Food Technology-II-Meat, Poultry, & Fish Industry in India PDF

Food Technology-II Module 6. Meat and poultry processing Lesson 19 PRESENT STATUS OF MEAT, POULTRY AND FISH INDUSTRY IN INDIA 19.1 Current Status of Meat Industry in India Animal f...

Food Technology-II Module 6. Meat and poultry processing Lesson 19 PRESENT STATUS OF MEAT, POULTRY AND FISH INDUSTRY IN INDIA 19.1 Current Status of Meat Industry in India Animal food is considered as good source of quality nutrients viz. fat, protein, carbohydrates and minerals. Digestibility of animal source protein is 90-97% while vegetable origin proteins have 75-99%. However, proteins of animal origin are more completely digested and nutritionally superior than those of plant origin. Protein digestibility corrected amino acid score (PDCAAS), protein efficiency ratio (PER) and biological value (BV) of animal and plant proteins are 0.9-1.0 and 0.42-0.70; 3-4 and 1.5-2.6; 74-94 and 65-73 respectively. On the other hand, plant origin proteins are deficient in at least one of more essential amino-acids e.g. some cereals in lysine and some legumes in methionine but the animal proteins contain all essential amino acids. India has the largest livestock population (485 million) which represent about 55% (96 million) and 16% of the world’s buffalo and cattle populations respectively (17th Census 2003). The country ranks second in goats, third in sheep and camels, and seventh in poultry populations in the world. Although India has been the top producer of milk (>115 MT, 15% global production) which is one of the primary produce of the livestock sector, the meat production is only 5 million tones annually representing mere 2% of the world production. Nearly three million tonnes of broiler meat and about 2.86 million tonnes of eggs are produced annually in India. Growing at about 20 per cent annually the domestic poultry market is currently estimated at about Rs. 49,000 crore. The domestic market is mostly confined to fresh meat because of the eating habits of the Indians. Therefore hardly 40-50% of the total processing capacity of over 1 million tones per annum is utilized. Among processed meat, 6% of production of poultry meat is sold in the processed form of which only 1% is marketed as value added ready-to-eat/ready-to-cook types. Of the total meat produced, only about 1% is converted into value added products like sausages, ham, bacon, kababs, meatballs, etc. www.AgriMoon.Com 118 Food Technology-II Buffalo meat production was at 2.85 million tons in 2010 and is expected to increase marginally through 2012 (growing at 3%). The growth is primarily due to increasing domestic consumption, growing exports and a new trend of raising male buffalo calves for meat production. Spent buffalo cows are also used for meat purpose. Currently, the processing level of buffalo meat is estimated at 21%. The buffalo meat share in total meat exports from India is more than 90 percent (in value terms), followed by 3% per cent share of goat and sheep meat and the rest comprising of poultry meat and animal casings. Exports of other types of meats such as from pork, poultry, and processed meat are almost negligible due to higher costs, inadequate meat processing facilities, and infrastructure constraints. For exports mostly deboned frozen buffalo meat is used. The demand for bovine meat has increased over the years in the global markets resulting in higher prices of cattle meat. This has opened new opportunities for us and led to increase in buffalo meat exports from India in recent years. Beef exports are forecast to rise 5 percent in 2012 on robust global demand, particularly to Southeast Asia, the Middle East and North Africa. India accounts for nearly half of world growth in 2012 on increased supplies and price-competitive shipments to emerging markets. The export is restricted to very few products. The export from sheep and goat is very low. As per APEDA statistics (2010-11), the export of buffalo meat is 7, 09,437tonnes (Rs. 8412 crore), processed meat 1,19,08 tonnes (value Rs 253 crore), poultry products 6,19,150 tonnes (Rs 301 crore) while that of animal casings it is 1809 tonnes (Rs. 35 crores). Buffalo milk is not very remunerative because of competitive disadvantages and the export is largely restricted to few countries in the Middle East. Slaughter rate for cattle as a whole is 20%, for buffaloes it is 41%, pigs 99%, sheep 30% and 40% for goats. In India there are about 3,900 licensed & authorized slaughter houses besides around 26,000 unauthorized slaughter houses. Furthermore, there are 13 export-oriented, modern, integrated abattoirs or meat processing plants registered with the Agricultural and Processed Food Export Development Authority (APEDA). In addition to these, there are 24 meat processing and packaging units, which receive dressed carcasses from approved municipal slaughter houses for the export of meat. According to the Ministry of Food Processing Industries (MFPI), about 70% of poultry processing is in the organised sector and 30% is in the unorganised sector. Nearly 60- 70% of the broiler industry is located in the southern states, as is much of the layer industry. www.AgriMoon.Com 119 Food Technology-II Per capita consumption of meat from beef and veal put together in 2011 was only 1.6 kg. Mutton and lamb is relatively smaller segment where demand is outstripping supply, which explains the high prices in domestic market. The production levels have been almost constant at 950,000 MT with annual exports of less than 10,000 MT. This has restricted large processing companies from developing business interests in this sector. Production of meat is governed under local by-laws as slaughtering is a state subject. Processing of meat is licensed under the Meat Food Products Order (1973). 19.2 Status of Poultry Sector India is the third largest producer of eggs and ninth largest producer of poultry meat in the world. The poultry industry has registered significant growth. In 2010-11, India’s egg production reached 61.5 billion eggs, up 68% from 36.6 billion in 2000-01. As per FAOSTAT latest production data for the year 2010, India ranks 3rd in egg production in the world. Poultry exports are mostly to Maldives and Oman. Indian poultry meat products have good markets in Japan, Malaysia, Indonesia and Singapore. Among Indian states, Andhra Pradesh stands as the highest egg producer. Both public and private sector organizations have played important role in the poultry industry. India at present has only five egg powder plants which is inadequate considering the fact that export demand for different categories of powder viz., whole egg, yolk and albumen are increasing. There is a huge scope for the growth of poultry industry as the country's annual per capita consumption is only 2.4 kgs. Per capita consumption has grown from 1.22 kgs in 2001 to 2.26 kgs in 2010, an increase of 185%. The National Institute of Nutrition has recommended 180 eggs and 11 kg of meat per capita consumption for our country India's poultry product exports are mainly confined to eggs and egg powder, which are growing due to cost competitiveness and logistical advantages. There are no restrictions on exports of poultry and poultry products. The government provides some transportation subsidies (Rs 3-15 per kg) for its exports. For the development of meat export from India the industry has demanded some immediate measures like financial assistance for upgradation of export oriented abattoirs/processing plants. Inclusion of buffalo meat under APEDA's Transport Assistance Scheme for new markets in Africa/CIS (Commonwealth of Independent States) where freight cost from India for refrigerated containers is much higher than from competing countries. Restoration of DEPB rates for frozen buffalo meat. Exemption from Service Tax on transportation of meat www.AgriMoon.Com 120 Food Technology-II products processed for exports. This is presently applicable only for fruits, vegetables, eggs or milk even for domestic consumption. 19.3 Status of Fisheries Sector India is the second largest producer of fish in the world, contributing about 5.54 percent of the global production. The total fish production during 2010-11 was 8.29 million tonnes with a contribution of 5.07 million tonnes from the inland sector and 3.22 million tonnes from the marine sector. The value of output from the fisheries sector at current prices during 2009-10 was Rs. 67,913 crore which is 4.9 per cent of the total output of agriculture & allied sectors. India’s marine product exports have for the first time crossed USD 2 billion. During 2010- 11, the volume of fish and fish products exported was 8,13,091 tonnes worth Rs. 12,901 crore registering the highest growth rate of 10% in volume of fish exports in recent years. 19.4 Future Strategies for Sustainable Growth of Meat, Poultry and Fisheries Sectors In view of the immense potential of the meat, poultry and fisheries sector, policymakers have recommended certain critical measures to support this vital segment of the Indian agriculture. Modernization of abattoirs, setting up of rural abattoirs and registration of all slaughter houses in cities/towns are essential for quality meat production. Besides, setting up of large commercial meat farms have been recommended to address the traceability issues necessary for stringent quality standards of CODEX. It has also been suggested that the goat sector has immense potential and needs to be supported in terms of higher investment, community approach and establishment of proper linkages between the processing industry and the market. Similar approach is needed for sheep sector which has remained almost static for a long time. Poultry sector in the country has now emerged as organized industry and important issues like breeding farms, hatchery, feed mills, equipment manufacture, feed supplements, drug and vaccine production, etc. have been addressed in a very satisfactory way. However marketing of the final product still remains mostly in the hands of traders which need to be addressed properly. The other important issues for the poultry sector are improved Feed Conversion Ratios (FCR) and quick control measures for tackling disease outbreaks.The overall growth rate in livestock sector is proposed to be revised to 5 per cent during the current Plan with a 4 per cent growth rate for milk sector and 6–8 per cent for poultry and meat sector. www.AgriMoon.Com 121 Food Technology-II The marine fisheries sector is expected to grow at the rate of 2.0 percent annually and it is estimated that 3.669 MMT of marine fish would be harvested by the year 2016-17. With this production, the country will be exploiting about 83 percent of its potential harvest of 4.419 MMT. The developments and trends in fish production in the inland sector suggest that a growth rate of 8.0 percent can be achieved by the inland sector. With this growth rate, it is estimated to reach a fish production target of 7.910 MMT by the end of the Twelfth Plan Period (2016-17). The strategies adopted for achieving the targets are to include integrated approach for enhancing inland fish production and productivity with forward and backward linkages right from the production chain. This has to also include input requirements like quality fish seeds and fish feeds and creation of required infrastructure for harvesting, hygienic handling, value addition and marketing of fish. It is proposed to revamp the Existing Fish Farmers Development Authority (FFDAs) and cooperative sectors, besides actively involving the self help groups and youths in intensive aquaculture activities. Sustainable exploitation of marine fishery resources especially deep sea resources and enhancement of marine fish production through sea farming, mariculture, resource replenishment programme like setting up of artificial reefs etc are the other measures that could enhance marine fisheries sector. *****☺***** www.AgriMoon.Com 122 Food Technology-II Module 6. Meat and poultry processing Lesson 20 PRE SLAUGHTER HANDLING AND INSPECTION OF ANIMALS 20.1 Introduction Pre-slaughter handling of meat animals includes procedures adopted during transportation, pre-slaughter rest and ante mortem inspection. 20.2 Transportation of meat animals Animals are taken to the slaughter house either on hoof or through road/rail/sea transport. Whatever the means, what is of paramount importance is that the animals must not be subjected to cruelty. There are legislations against cruelty to animals and procedures recommended need to be strictly adhered to. If the animals are carried by road or rail care needs to be taken to avoid overcrowding which may lead to suffocation and physical injuries in the form of bruises, fractures etc. Tying or chaining of the animals is to be avoided. There are specially designed trucks and wagons available to take care of such issues and should be used as far as possible. 20.3 Pre-slaughter rest Pre-slaughter rest is the period before slaughter when animals are rested in order to improve the meat quality and reduce the chances of contamination with gastrointestinal bacteria. During pre-slaughter rest fatigue could have negative influence on protective functions of the animals (low immunity) allowing rapid penetration of the microorganisms especially E Coli through mucous membrane of the intestine to the blood stream and ultimately to the organs. Normal feeding and resting for 48 hours brings gradual freeing of muscles and other organs from microorganisms, improve bleeding and keeping quality of meat. Pre-slaughter rest also helps in preserving glycogen level in the muscles and during the later phase this glycogen undergoes anaerobic respiration and results in production of lactic acids which has mild preservation effect on meat quality. Under stressed conditions muscles do not receive enough oxygen which leads to higher lactic acid production often associated with comprised quality in terms of colour, texture and water holding capacity. www.AgriMoon.Com 123 Food Technology-II 20.4 Ante-mortem inspection It refers to inspection of food animals conducted prior to (12 to 24 hr) slaughter to ascertain fitness or otherwise of the animals for slaughter. 20.4.1 Objectives of ante-mortem inspection 1) To detect the animals suffering from infectious or scheduled diseases (communicable to animals or human beings) such as FMD, Rabies, Anthrax, etc. 2) To detect diseases causing toxic or infectious conditions and which may escape detection in post mortem examination. 3) To prevent outbreaks of food poisoning resulting from the consumption of meat from animals which were ill at slaughter 4) To make post-mortem inspection more efficient and less laborious. 5) To document information on animal diseases prevalent in the region. To prevent the use of meat from animals suffering from febrile condition. 20.4.2 Facilities for conducting ante-mortem inspection 1. For successful ante-mortem examination, procedure for adequate identification of the animals to be slaughtered need to be followed. 2. The lairage should be properly designed, well lighted and ventilated 3. The lairage should have provision for isolation pens 4. There should be competent assistant staff for handling of livestock and above all a competent veterinary officer must be available. 5. A well designed code on veterinary ante-mortem inspection procedures, judgement principles and documentation of findings need to be maintained. 20.4.3 Procedure for ante-mortem inspection Immediately after the animals arrive at the slaughterhouse, they are examined by qualified veterinary personnel before being sent to the lairage where ante-mortem inspection is carried out 12 to 24 hours before slaughter by the qualified veterinarians. Ante-mortem inspection can be carried out in two stages: www.AgriMoon.Com 124 Food Technology-II 20.4.3.1 Stage-I: General examination The animals are to be examined collectively to assess the overall health status so as to segregate them into three groups: 1) Healthy 2) Unhealthy (diseased) 3) Apparently healthy (doubtful cases) The animals are examined while they are at rest and also in motion They are observed for the gait, posture, fatigueness and for their response to external stimuli. They are examined for abnormal behavior like walking in circles, state of alertness, symptoms of tiredness and agitation Animals are examined for abnormal discharge from natural orifices like eyes, nose, mouth, anus, vagina etc. and/or swellings on any part of the body. It is also important to observe for any evidence of cruelty to animals such as any sign of bruises, torn skin, and fractured bone indicating carelessness during transportation. At the end of the first stage of examination, healthy animals are cleared as “fit” for slaughter whereas the other two groups are taken to the next stage of examination. 20.4.3.2 Stage-II. Detailed clinical examination The animals classified as unhealthy (diseased) are subjected to further examination to correctly diagnose the illness while the animals placed in group three (Apparently healthy or doubtful cases) are examined to ascertain whether these animals are really sick and if so what could be the nature of illness. Animals are subjected to the following investigations: (i) Temperature, pulse and respiration rate should be recorded and animals suffering from fever must be retained for treatment preferably outside the meat plant. (ii) The lymph nodes are palpated and examined for any swelling and abnormalities and on this basis the animals are either rejected or passed with clear instructions for careful post-mortem examination (iii) Pregnant animals or animals having delivered a calf within the last 48 hours are not permitted for slaughter. Animals undergoing treatment or with a recent history of treatment as also experimental animals are not to be slaugthered unless a ‘no objection certificate’ has been issued by veterinarians. (iv) Blood, urine and faeces samples to be drawn for laboratory tests www.AgriMoon.Com 125 Food Technology-II (v) Pathoganomonic clinical symptoms of the diseases for suspected animal to be carefully studied. (vi) The species, class, age, condition, colour and markings re recorded in case of diseased or sick animals and in case of the animals in poor condition. Table 20.1: Diseases and abnormalities encountered in ante-mortem inspection General Specific infections conditions Cattle Calves Sheep Swine Moribund and Actinomycosis Immaturity Pneumonia Arthritis, exhausted status Emaciation Actinobacillosis Calf Caseous Atrophic diphtheria lymphadenitis Anasarca Tuberculosis Arthritis Enterotoxaemia Rhinitis Poorness Blackleg Ringworm FMD Swine Fever External injuries FMD White Scour Swine Localized Anthrax Salmonellosis Erysipelas swellings a) tumours b) abscesses c) oedema d) haematoma e) hernia Inflammatory Rinderpest Swine conditions of skin a) urticaria b) eczema Pregnancy Mastitis Tuberculosis Fractures Ringworm FMD Pneumonia Dysnoea Retained placenta Discharges from natural orifices www.AgriMoon.Com 126 Food Technology-II 20.4.4 Judgment decisions at ante-mortem inspection Post anti-mortem inspections, the animals can be subjected to any of the following three decisions. Passed/Accepted/ Fit for slaughter: The animals free from any disease and normal can be directly sent for slaughter. Rejected/ Condemned/ Unfit for slaughter: Animals suffering from fever (106oF or more), emaciated or dead animals, immature or pregnant animals are considered unfit and not passed for slaughter. Animals with established symptoms of diseases are not sent for slaughter. Suspect: Animals falling under this category are those for which decision regarding fitness for slaughter cannot be made at the ante-mortem inspection stage. The following possibilities exist under these circumstances. (a) Slaughter under special precautions: Animals under suspect category if having symptoms of diseases. (b) Delayed/Detained slaughter: If the animals require treatment, or have history of recent treatment/vaccination, animals in febrile condition, fatigued and exited state may require treatment before they are slaughtered. (c) Segregated slaughter: Such decisions are made under special conditions such as dirty stock or animal suspected for some contagious diseases etc. Such animals are slaughtered at the end of the day’s kill or separately slaughtered and a thorough post- mortem examination is performed. (d) Casualty and emergency slaughter: Casualty slaughter is required when an animal is not in acute pain or immediate danger of death but affected with a more chronic condition like benign superficial tumors, obturator paralysis and post- partum paraplegia etc. When an animal is in acute pain or suffering from condition like, fractures, severe injuries, uterine prolapsed etc., where a delay in slaughter would be contrary to the animal welfare, then animals requires emergency slaughter. Prolonged recumbency in cows and sows after parturition, abscess formation in pigs due to Corynaebacterium pyogenes, pregnancy toxaemia and enterotoxaemia in sheep and injuries and affections of udder and uterus in cattle are the several other causes of emergency slaughter. www.AgriMoon.Com 127 Food Technology-II I. “Fit” for slaughter. II. “Unfit” for slaughter and the animal is condemned at ante-mortem. III. “Suspect Animals” which fall under 2 categories (a) “slaughter under strict supervision” (b) “retain for a specified period” enabling +he symptoms to develop or subside and thereupon take a final decision on slaughter (fit/unfit/slaughter under strict supervision). *****☺***** www.AgriMoon.Com 128 Food Technology-II Module 6. Meat and poultry processing Lesson 21 SLAUGHTERING TECHNIQUES AND POST-MORTEM INSPECTIONS 21.1 Slaughtering Procedures After the animals have been rested for sufficient time, they are quietly taken to the stunning area. Animals may be facilitated through mechanical means like canvass straps or rolled plastic or prodded to move forward. However tail twisting or beating is forbidden. Slaughter animals are properly restrained before stunning or bleeding. Different types of restraints are used for different species. 21.1.1 Stunning It is a process to inactivate animals so that it is not able to move. It is an obligatory process with large animals. Stunning ensures that the animal is unconscious before it is slaughtered in order to eliminate pain, discomfort and stress from the procedure. Many countries have legislation that requires pre-slaughter stunning. Care should be taken not to affect the heart and it should function normally to ensure complete bleeding which ensures better meat quality. Stunning is done in special stunning pan (box with movable side wall). 21.1.1.1 Stunning methods 1. Most common method employed is striking on the head with a wooden hammer or captive bolt. However blow should not damage the frontal bones as it may cause brain hemorrhage. 2. Electrical stunning: An electric current of 75-120 volt is passed for 15-70 seconds through the hind part of the animal head in the regions of parietal boxes by puncturing the skin. This causes unconsciousness of the animals which may last for 5 min and it is enough to transfer the animal from stunning pan to bleeding runway. 3. Anesthetization: Anaesthetization may be carried out on swine using a mixture of CO2 and air in equal volume with 0.18% chloroform and the inhalation period may last for one min. www.AgriMoon.Com 129 Food Technology-II 21.1.2 Slaughter The most common methods of slaughter practiced worldwide are the Halal (Islamic), the Kosher (Jewish) and the Jhakta (Sikh) methods. Halal: Halal is one of the most popular method of slaughter. This method prescribes slaughtering of animals with a sharp knife to make a swift, deep incision that cuts the front of the throat, the carotid artery, wind pipe and jugular veins but leaves the spinal cord intact. The animal is then hung upside-down and left to exsanguinate i.e drainage of blood. The Halal slaughter requires that the name of Allah (or God) should be mentioned at the initiation of the operation. This method of slaughter ensures that the blood flows out completely from the animal. Jhatka: It is an instant decapitation process limited mostly to sheep and goats and practiced in countries like India by few religious sects. The animals are killed by a single strike of a sword or axe by severing the head Jewish Slaughter (Kosher): “Kosher” is the term applied to the procedures and techniques of slaughter practiced under the Jewish faith. In Hebrew language, Kosher means fit to be used as food. Under this method of slaughter, the animals in fully conscious state are killed and bled thoroughly by one clean stroke of the knife. Animals are however hoisted and shackled first. A 16-inch (40.6 cm) razor-sharp steel knife called the chalaf is stuck into the throat by a trained slaughterer, the shohet, in an operation in which the animal is killed and bled at the same time. Skinning is made from the chest down to the level of the belly, and the chest is cut open first for inspection and later evisceration. 21.1.3 Bleeding Bleeding is a procedure in the slaughter process which is performed by cutting jugular vein in the neck and carotid artery in order to allow blood to drain from the carcass, resulting in the death of the animal from cerebral anoxia. The bleeding knife should be continuously sharpened as a blunt knife may prolong the incision and damage the cut ends of the blood vessels. This may result in premature clotting and blockage of the vessels thus delaying the bleeding process. A prolonged delay in bleeding could result in the animal regaining consciousness. The delayed bleeding may also result in an increase in blood pressure causing the blood vessels to rupture and haemorrhage of muscle. The extra blood in the tissues may lead to meat getting decomposed quickly. Incisions www.AgriMoon.Com 130 Food Technology-II should be therefore swift and precise. In poultry, sheep, goats and ostriches, the throat is cut behind the jaw. 21.1.4 Skinning After successful bleeding, first the head is skinned, separated from the body, marked with the same number as the body and then hung on hook for post mortem examination. ‘Skinning’ is a term mostly used for small ruminants and the method of skinning is known as “case-on”. The skinned materials are called as “skins”. Skin is the most valuable byproduct economically. In sheep and goats, skin is first cut around the leg to expose and loosen the tendon of the hock and used for hanging the carcass. This process is called legging. The second step that follows is called skinning which involves removal of the entire skin and preparation of the animal body for evisceration. Skinning can be done either in the horizontal or hanging position depending on the convenience and available facilities. If animal body is in hanging position, legging is generally started at the back of the free leg by removing the skin around the hock and continued towards the toes. This exposes the tendon on the back leg and the foot is cut off at the joint above the toe. The body skin is removed by making an opening in the front legs, cutting towards the jaw and continuing over the brisket to the naval. Once the brisket has skinned, knife is seldom used to protect the “fell” (a fine membrane between the skin and the carcass). This helps in improving carcass appearance and reducing surface shrinkage. This is largely accomplished by using fist/hand. After the skin has been removed, the carcass is washed and placed on a hook. In horizontal skinning the animal is placed on its back on a flat raised surface and similar process repeated. This operation is absent in pigs, because skin is a part of the carcass. In the case of large ruminants (cattle and buffaloes), cuts are made on the skin along the mid-ventral line and also on the medial side of the limbs connecting to the respective points (sternum and pelvis) in the mid-ventral line. Skinning of large ruminants is known as “flaying” and the incisions made on the skins are known as “ripping lines”. The deskinned materials are called as “hides. 21.1.5 Evisceration It should be carried out without damaging the internal organs or disturbing the internal surface of the carcass. Damage to the gastro-instestinal tract (GIT) may contaminate the carcass with the www.AgriMoon.Com 131 Food Technology-II microorganisms. The first step in evisceration is to cut around the tied bung or rectum and free it completely from all attachments. The breastbone is then cut along the midline up to its tip. Another cut is made from the cod or udder down the midline into the breast cut. Then the ureter connections to the kidneys are severed and the intestines loosened. The stomach and intestinal mass are removed. The lever could be detached from its connecting tissues and then pulled out along with the contents of the abdominal cavity. The gall-bladder is carefully removed from the liver so that its content does not spill out and contaminate the carcass. The pluck consisting of heart, lungs, trachea and esophagus can be pulled out as a unit. The carcass is then washed and carried manually or mechanically to the inspection area. 21.1.6 Carcass splitting and sizing In the slaughterhouses, carcasses of small ruminants are not split into sides or quarters; carcasses of large ruminants are split into four quarters; and carcasses of pigs are split into two sides. Therefore, at the retail meat stalls selling buffalo meat, pork and mutton, we find quarters, sides and whole carcasses of respective animals. Carcasses are sawed by electric or pneumatic saws starting from the hind part to the central vertebrae. This facilitates transport, storage and efficient refrigeration. 21.2 Post Mortem Examination Postmortem examination/inspection refers to inspection of carcass and organs by qualified veterinarians to ensure that carcass and organs are fit for human consumption. During inspection, care should be taken not to contaminate the carcass and organs from diseased animals. The knives and other instruments used for cutting and examining organs, glands and tissues should be properly sterilized before and after use. The particular sequence should be followed during postmortem examination so that each carcass and thereof organs are checked thoroughly. 21.2.1 Objectives of postmortem examination Carcasses should not be sent to the chilling section without inspection after dressing. Some of the diseases are not apparent during ante mortem examination can be detected easily in postmortem examination. Thus, post mortem inspection ensures safe meat to the consumers and also controls diseases right at the farm level itself. It also directs to adopt a proper disposal procedure for www.AgriMoon.Com 132 Food Technology-II condemned meat and offal. Since postmortem inspection is performed for carcasses as well as their viscera, it ensures a systematic way of evisceration and handling of offals. 21.2.2 Facilities required for postmortem examination The area where the examination is being conducted should have sufficient and well distributed light. The natural light is considered better than artificial light. The intensity of light must be 540 lux The person carrying inspection need clean, sharp, stainless knives There must be provision for hot and cold water There should be a sterilizer to sterilize the knives, saws and cleavers. The postmortem examination should be carried out under hygienic conditions. The knives should be sterilized by dipping them in boiling water for 30 minutes or by autoclaving them for 10-15 minutes. (The sterilization of anthrax contaminated knives requires special consideration). To put a mark on carcass and its viscera, marking dyes should also be provided, which should be cheap, non-toxic and non-corrosive in nature. Marking indicates that the carcass has been inspected and guarantees the consumer about is wholesomeness. Marking of meat is done by (i) using a stamp (ii) branding or (iii) labeling. Common method – Metal stamp dipped in a stamping ink. There should be provision of detained room side by the inspection site. 21.2.3 General consideration Following points should be considered during postmortem examination/ inspection: The examination must be done as soon as possible. Carcasses of beef and pork set rapidly and if the inspection is delayed especially in cold weather the examination of lymph nodes becomes difficult. Carcass and organs are to be examined methodically following a definite sequence. Healthy carcass should be examined before inspecting the diseased or suspected ones. Great care must be taken at the time of inspection particularly in cases suspected for zoonotic diseases. The identity of carcass and its viscera should be maintained. www.AgriMoon.Com 133 Food Technology-II Inspector should avoid unnecessary cuts considering the value of high quality food. One should incise the carcass in such a way that the surface of the carcass appears clean and undistorted. 21.2.4 Postmortem principles 21.2.4.1 Visual perception First the carcass and visceral organs should be examined visually for any visible abnormalities. Examination is done for any change of colour, atrophy, hypertrophy, neoplastic condition etc. 21.2.4.2 Palpation The organs are palpated for any change in consistency, sliminess or gelation, cyst, etc. 21.2.4.3 Incisions The organs are incised, if needed. This is done to examine any parasite inside organ, structural deformity etc. 21.2.4.4 Laboratory tests These are done for confirmation and support the observation made by macroscopic examination. While examining the organs of carcass, lymph node of adjoining area must be examined. 21.2.5 Postmortem Examination of Carcasses 21.2.5.1 Large animals In case of large animals like cattle, sequence of postmortem examination is as follows: Head Verify the number, age and sex of the animal Inspect gums, lips and tongue for FMD, necrotic and other forms of stomatitis, actinomycosis and actinobacillosis (Palpate the tongue for the latter). Incise the internal and external masticatory muscles and tongue for Cysticercus bovis. Incise retropharyngeal, submaxillary and parotid lymph nodes for tuberculosis (TB) lesions. www.AgriMoon.Com 134 Food Technology-II For sheep & goat, the lips, gums and nasal cavities should be examined for contagious ecthyma. Lungs Examine visually and then palpate for the detection of pleurisy, pneumonia, tuberculosis, fascioliasis and hydatid cysts. Incise the bronchial and mediastinal lymph nodes and expose the lung by giving deep incision from the base to apex (for checking TB lesions). Check the tumors, abscesses etc. by palpation. Heart Examine the pericardium for traumatic or tubercular pericarditis. Incise the ventricles of the heart and pay attention to look for petechial hemorrhages on the epicardium and endocardium and cuts in the myocardium. Flavy condition of the myocardium is indicative of septic conditions. Liver A visual examination should be made for fatty changes, abscesses, hydatid cysts, actinobacillosis etc. For examination of fascioliasis, incise thin portion of left lobe of liver and examine the contents. For sheep and goat, lungs, heart and liver: (i) Palpate lungs, heart and liver and accompanying lymph glands for abscesses. (ii) Cut the bile duct for examining possible fluke infestation Stomach and intestines www.AgriMoon.Com 135 Food Technology-II Check the serous surface of the intestine for TB lesions and actinobacillosis. Palpate the mesenteric lymph node and if necessary incise and examine the same. Spleen Examine the surface and substance for TB lesion, anthrax, hematoma and presence of infarcts. Uterus Check for septic conditions by viewing, palpating and incising if necessary. Udder Check the supramammary lymph nodes by incising for the evidence of TB lesions. Check for abscesses if any. General inspection of carcass Look for the injuries and bruises. Bruises are dark colour after 24 hours and there is watery condition after 24 to 38 hours. After 3 days, the area becomes rusty orange colour and soapy to touch. Look for inflammation, abscesses and TB lesions in the thoracic and abdominal cavities. Examine the kidneys. Incise and examine renal lymph nodes. 21.2.6 Postmortem judgement Similar to ante-mortem examination, a competent veterinarian has to submit its judgment report: Fit for human consumption Unfit for human consumption or total condemnation www.AgriMoon.Com 136 Food Technology-II The affected organs must be condemned while rest can be passed for human consumption (partially condemned). The condemned carcass/ organs should be disposed off following scientific procedure. 21.2.7 Diseases and conditions for which carcass is totally or partially condemned The carcass is totally condemned for rabies, anthrax, glanders, rinderpest, foot and mouth disease, acute enzootic meningoencephalitis, acute pleurisy, contagious bovine pleuropneumonia, ovine foot rot, sheep pox, swine fever, swine erysipelas, salmonellosis, fibrinous rhinitis, black leg, bovine viral diarrhea, haemorrhagic septicaemia, listeriosis, pasteurellosis, coccidiosis, calf diphtheria, calf diarrhoea, malignant oedema, tetanus etc. The carcass in case of actinomycosis, actinobacillosis and Johne’s disease, is totally condemned if accompanied with emaciation and in generalized form, otherwise the carcass is passed for human consumption after local condemnation. In case of corynebacterium infection, carcass is passed after removal of affected organs. In case of heavy infestation (more than 10 cysts) with Cysticercus bovis and Cysticercus cellulose, carcass is totally condemned, otherwise the carcass is passed after removal of head, heart, diaphragm and esophagus. Trichinella spiralis infected carcass is totally condemned. If carcass show the sign of fascioliasis with emaciation then it is totally condemned, otherwise it is passed after trimming of liver. Carcass is passed for consumption after removal of lung in case of emphysema and broncheolitis. If there is no fever, then carcass with sign of gastroenteritis is unconditionally passed. The judgement of carcass suffered from tuberculosis depends on method of spread, extent of disease, character and age of lesion and general condition of the animal. Carcass is totally condemned when tuberculosis spreads through portal or pulmonary or systemic circulation. In case of localized tuberculosis, the carcass is passed after removal of the affected organs and associated lymph nodes. 21.2.7.1 Metabolic and nutritional disorders and intoxication The carcasses are totally condemned if they show any of the following sign: Anaemia with emaciation, (ii) grass tetany, (iii) haemoglobinuria, (iv) jaundice, (v) ketosis with chronic indigestion, (v) poisoning, (vii) bloat or (viii) impaction etc. www.AgriMoon.Com 137 Food Technology-II Abnormal conditions: Abnormal conditions like, abnormal colour, taste and smell, buck smell, bore smell etc. results in total condemnation of the carcass. *****☺***** www.AgriMoon.Com 138 Food Technology-II www.AgriMoon.Com 139 Food Technology-II Module 6. Meat and poultry processing Lesson 22 RIGOR MORTIS: BIOCHEMICAL AND HISTOLOGICAL CHANGES 22.1 Introduction Meat is basically defined as the flesh of animals used as food. The term meat generally differs from the muscle in the sense its structural and physicochemical nature as it (muscle) has undergone certain chemical and biochemical changes following death of an animal which is a postmortem aspect. Thus, during the time elapsed between death of an animal and its processing, a series of biochemical and physico-chemical changes takes place which lead to conversion of muscle into meat. 22.2 Muscle: Structure, Composition & functioning Muscle is made of number of fiber bundles (1.0 mm thick), comprised of a group of fibers, (0.1 mm thick) held together by a structure of connective tissues or perimysium (figure 22.1). Connective tissues which provide edible texture, structure and flexibility to the muscles, comprised of fibrous protein collagen, reticulin, and elastin. Muscle fiber, a unit of muscle contraction, is a multinucleate, cylindrical cell bounded by an outer membrane or sarcolemma and is consist of myfribils of 1-2 micron size. Myofibrils are separated by sarcoplasmic reticulum, a fine network of tubules. Each fiber is filled with sarcoplasm containing mitochondria, enzymes, glycogen, ATP, creatine, and myoglobin. The myofribrils are cross striated to give rise to understanding of physical structure of muscles (dark or A and light or I/Z bands). The unit of fibril is sacromere which lies between adjacent two Z- bands. Fibrils are consist of two set of filaments i.e. myosin and F-actin. Contraction and relaxation of striated muscles takes place due to interaction between actin, myosin and ATP. In the presence of magnesium and calcium ions, myosin liberates ATP which results in muscle contraction. The composition of muscle is highly variable depending upon specie, type of muscle, animal’s maturity and the treatments given to the animal before its slaughtering. Variation in the composition ultimately affects the nutritional and functional profile muscle tissues. www.AgriMoon.Com 140 Food Technology-II The lipid components of muscle tissue vary more widely than do the amino acid in fish muscle, the differences have been made in the concept of lean or white fish and fatty fish. In lean fish, storage fat is carried in the liver. Muscle of lean fish contains 2.0%) d) Sodium silicates e) Sodium phosphates 2. Acids: Remove hard deposits Strong acids are corrosive to metal such as water stones, such surface and dangerous also a) Nitric Acid deposits do not dissolve in b) Sulphuric Acid alkalies, generally HNO3 c) Hydrochloric Acid (0.5%) Phosphoric acid (2.0%) used d) Phosphoric Acid e) Acetic Acid 3. Complex Phosphates: Water softening, soil Excellent but unstable in hot solution displacement by and in presence of strong alkalies. a) Tetra sod. pyrophosphate emulsification, peptization b) Sod. tripolyphosphate prevention of redeposition c) Sod. tetraphosphate of soil d) Sod. hexametaphosphate 4. Chelating Agents: Sequestering, water softening, removal of EDTA (Ethylene diamine -- mineral deposition. tetra acetic acid) www.AgriMoon.Com 175 Food Technology-II 5. Wetting Agents: -- Wetting and penetrating properties a) Anionic (sod. salt of in soil various complex organic QAC are expensive. materials -- Stable dispersion b) Non ionic e.g. teepol -- Emulsion formation Alkaline cleaning agents are generally suitable for removing organic dirt, protein residues and fat, while acid cleaning agents are used particularly for removal of encrusted residues of dirt or protein or of inorganic deposits (“scaling”) such as waterstone, milkstone, lime etc. On the other hand, Neutral cleaning agents have much less effect than alkaline or acid cleaning agents, but have mild impact on skin and materials and are useful for manual cleaning of smooth surfaces without encrusted dirt. In practice alkaline and acid cleaning substances should be used alternatively. 25.2.3 Disinfection techniques The elimination of microorganisms is achieved through disinfection, either by using hot water (or better steam) or chemical disinfectants. Chemical disinfectants are preferred for most applications in the meat industries as they are easy to use and do not involve the risk of accidents or other negative side effects such as damage to equipment by generating high humidity or water condensation, which may occur when using steam. Best results are achieved when chemical disinfection is preceded by intensive dry/wet cleaning. 25.2.4 Disinfectants for the meat industry Disinfectants should be effective and rapidly acting in killing microorganisms. In principle the following groups of substances are generally used as disinfectants: (i) Chlorine containing compounds e.g. Na/Ca hypochlorite or chlorine gas, has a corroding effect on equipment. (ii) Aldehydes (used in animal production, e.g. Formaldedyde) Phenoles / Kresols (used in medicine, households Alcohols (used in medicine, e.g. skin) Alkalines (pH 10 or higher) (e.g. NaOH, used in animal production) Acids (some organic acids used in food industries). Quaternary ammonium www.AgriMoon.Com 176 Food Technology-II compounds Amphotensids (used in food industries, as not corrosive) Low efficiency on spores. They have effect on cell walls, not corrosive, odourless, additional cleaning properties (surfactant) (iii) Oxygen releasing compounds e.g. Peroxide compounds (H2O2) Per-acetic acid (use in food industries). Penetrate into cells, good effect on all microorganisms including on spores and virus, odourless, may be corrosive in concentrations >1% An example of the optimal combination of disinfectant commercially used is organic acids surfactants (= surface active agents) peroxide compounds The organic acids, apart from their sanitizing effect, decrease the pH as some disinfectants are more efficient at lower pH. The surfactants assist in penetrating organic material. The peroxide compounds have the direct antimicrobial effect by coagulation and denaturation of proteins (virus) and penetration through cell walls causing cell destruction (bacteria). 25.2.5 Cleaning and disinfection (sanitation) schemes Several daily disinfections (by hot water or chemicals) are necessary for hand tools, meat saws and cutting boards. Daily disinfection is useful for dismantled equipment such as parts of grinders, fillers, stuffers, etc. Disinfection once a week is recommended for other equipment and floors and walls of processing and chilling rooms. 25.2.5.1 Cleaning and disinfection plans Specific cleaning and sanitization plans should be developed for specific processing areas eg. Meat storage, processing etc. An example of such plan is given in table 25.2 for disinfection of meat processing equipment, in this case for a meat grinder. This type of equipment is an integral part of www.AgriMoon.Com 177 Food Technology-II almost every meat processing line. Meat grinders require particular careful and frequent cleaning and sanitation, as the output product minced meat is hygienically very sensitive. Table 25.3 Cleaning and disinfection plan Equipment: Meat grinder Pre-cleaning Potable water Temp.: 40-50°C Pressure: 20-30 bars Cleaning Daily 1 x monthly Agent: A Agent: B Concentr.: 1.0% Concentr.: 1.5% Temp.: 40-50°C Temp.: 40-50°C Time: 20-30 min Time: 20-30 min pH: approx. 12 pH: approx. 1.8 Rinsing Potable water Temp.: 30-50°C Pressure: 5-10 bars Drying Disinfection 2 x weekly 3 x weekly Agent: C Agent: D Concentration.: 0.5% Concentr.: 1.0% www.AgriMoon.Com 178 Food Technology-II Temp.: 30-40°C Temp.: 30-40°C Time: 30 min Time: 30 min pH: approx. 5.7 pH: approx. 10.2 Rinsing Potable water Temp.: 30-50°C Pressure: 5-10 bars Agent A: Alkaline cleaning substance (Source:Heinz and Hautzinger, 2007) Agent B: Acid cleaning substance Agent C: Disinfectant Agent D: Disinfectant chemically different from C and supplementing impact of C *****☺***** www.AgriMoon.Com 179 Food Technology-II Module 7. Egg and egg processing Lesson 26 EGG: STRUCTURE, COMPOSITION AND QUALITY 26.1 Introduction Egg is a complete food consumed throughout the world. Eggs of various birds may be eaten however eggs of hen and duck are most commonly consumed. Egg protein contains all the essential amino acid and has got highest biological value. Thus egg proteins are considered by the WHO to be the reference protein, to which all other proteins are compared. An average weight of hen egg is about 2 ounce i.e. 57g 26.2 Structure and Composition of the Egg Whole Egg can be divided into three major components 1. Shell 2. Egg white 3. Egg yolk 26.3 Composition of Egg Table 28.1 Composition of Egg Component % Water % Protein % Fat % Ash % Whole egg 100 65.5 11.8 11 11.7 Egg white 58-60% 88 11 0.2 0.8 Egg yolk 31-33% 48 17.5 32.5 2 Shell 9 – 12% www.AgriMoon.Com 180 Food Technology-II 26.3.1 Shell It is the Outer covering of Egg, contributes to 9 – 11% of the whole egg weight. 94% of the egg shell is composed of calcium carbonate. It Acts as a barrier against harmful bacteria and other contaminants. Shell has got numerous pores on its surface, permitting moisture and carbon dioxide to move out and oxygen to move in as egg ages. Strength of the shell indicates the quality of the egg and strength is influenced by mineral and vitamin content of the hen’s diet, mainly calcium, phosphorous and Vitamin D. Inside surface of the Shell is lined by a mucous layer also known as protective layer called cuticle or bloom. Cuticle preserves the freshness of the egg by blocking the pores on the shell. 26.3.2 Egg white It is also known as Egg albumin, it contributes to about 65% of the egg’s liquid weight. It contains more than half of the egg’s total protein. Egg white becomes thin as an egg ages because protein changes in character. Hence fresh eggs sit up tall and firm in the pan while older ones tend to spread out. As the egg ages, carbon dioxide escapes out, so the albumin becomes more transparent than the fresh ones 26.3.3 Egg yolk The yolk or yellow portion makes upto about 33% of the liquid weight of the egg. It contains all of the fat in the egg and about 45% of total egg proteins. 26.4 Structure of the Egg www.AgriMoon.Com 181 Food Technology-II Source: USDA Fig. 28.1 Structure of the egg 26.4.1 Factors affecting quality of egg 1. Age of the egg 2. Storage atmosphere 3. Temperature of storage 4. Relative humidity 5. Pre-treatments given before storage www.AgriMoon.Com 182 Food Technology-II 26.4.2 Testing the quality of egg 1. Water test: this test is based on the principle of density. Eggs are simply dropped into water. Good quality eggs sink to bottom and poor quality ones float. Loss in weight is due to dehydration and thus increased air cell size. 2. Sensory test: Cracked, smelly, rough surface indicates poor quality 3. Candling test: This is the most commonly used test to determine the spoilage of egg. The egg shell is porous and allows the light to pass through. The eggs to be tested are placed in front of sharp, bright light and assessed for following factors a. Cracks on the shell b. Air cell size and position c. Albumin and yolk position and firmness d. Presence of any blood clot or foreign elements in the egg 26.4.3 Nutritional qualities of egg Eggs are nutritionally rich and one of the nature’s most complete food. They provide 173Kcals/100g. 26.4.4 Proteins Egg contains high quality complete protein with all the essential amino acid in well balanced proportion. Biological value of egg protein is 100, indicating all of the protein consumed is retained by the body. Egg white, also known as Albumin, contributes to the 60% of total proteins present in Egg and the rest is from Egg yolk. Nearly 50% of the protein in egg white is Ovalbumin, followed by Conalbumin (13%), Ovomucoid (10%), Lysozymes (3.5%), Ovomucin (2%), Avidin, Ovoglobulin and Ovoinhibitor. www.AgriMoon.Com 183 Food Technology-II Vitellin is the protein present in Egg yolk, which is present in a lipoprotein complex as lipovitellin and lipovitellinin. Phosvitin phosphorus-containing and Livetin sulfur-containing protein are also present in egg yolk. Avidin is protein present in the egg while which binds the vitamin biotin thus makes it unavailable to the body. 26.4.5 Fat Fat is concentrated in the Egg yolk. Yolk fat can be divided into 3 major parts i.e. Triglycerides, phospholipids and lipoproteins. Lipoproteins are present in conjugation with phospholipids. The primary phospholipid present in egg is lecithin and major sterol is cholesterol. The major Triglycerides present in egg yolk are Oleic acid 38.45% Palmetic acid 23.50% Linoleic acid 16.4% Stearic acid 14.0% of total fatty acids 26.4.6 Carbohydrate Glucose, Mannose and galactose are present in small amounts. This will take part in maillard reaction producing an undesirable brown discoloration in both dried and cooked egg whites. 26.4.7 Micronutrients The major micronutrients present in egg are vitamins and minerals. Egg is the rich source of all known vitamins except vitamin C. All the fat soluble vitamins A, D, E are concentrated in yolk. Minerals such as iron, phosphorus, zinc, iodine, potassium, sodium, chlorine and sulphur are present in good amounts. Iron present in egg is bound to conalbumin and therefore its absorption is poor while Zinc is present in the most abundant biologically active form. www.AgriMoon.Com 184 Food Technology-II Module 7. Egg and egg processing Lesson 27 PROCESSING OF EGG 27.1 Introduction Egg products are processed and convenience forms of eggs for commercial, foodservice and home use. These are refrigerated liquid products, frozen products, dried and specialty products. When shell eggs are delivered to the breaking plant, they are put into refrigerated holding rooms. Before breaking, they are washed in water at least 20 degrees warmer than that of the egg and spray-rinsed with a sanitizing agent. They may be moist, but not wet, when they are broken. 27.2 Classification of Egg Products Egg is processed to produce convenience forms of eggs for commercial, food service and home uses. Egg products can be classified as follows 1. Refrigerated Liquid products Egg whites, Egg yolk, various blends of Yolk and white 2. Frozen products Egg white, Egg yolk, Salted yolks, Sugared yolks, Whole eggs, Salted whole egg 3. Dried/Dehydrated products Spray dried egg white solids, Instant egg white solids, whole egg or yolk solids, free flowing whole egg or Yolk solids (sodium silicoaluminate added as a free flowing agent). www.AgriMoon.Com 185 Food Technology-II 4. Specialty Products Freeze dried scrambled eggs, Frozen precooked products like Egg patties, Fried eggs, crepes, Egg pizza etc. Egg products are preferred to shell eggs by commercial bakers, food manufacturers and the foodservice industry because they have many advantages including convenience, labor savings, minimal storage requirements, ease of portion control, and product quality, stability and uniformity. As per egg product inspection act all egg processing plants must follow below conditions: Pasteurization of all egg products is mandatory. Shell eggs used for egg products must be clean and of edible interior quality. 27.3 Frozen Egg Products These include separated whites and yolks, whole eggs, blends of whole eggs and yolks or whole eggs and milk and these same blends with sugar, corn syrup or salt added. 27.3.1 Production of frozen egg www.AgriMoon.Com 186 Food Technology-II Fig. 27.1 Process flow chart for frozen eggs Eggs are frozen to preserve them for use in food manufacturing. Before freezing, egg contents are separated from the shell and which may be frozen as whole egg, Egg yolk, Egg white or various mixtures of yolk and white. Freezing plants are generally combined with egg breaking facilities where eggs are received, washed and dried. Then the eggs are broken to remove the egg content this could be done by hand or with the help of machines. While breaking the spoiled eggs are rejected as this could spoil the good product. The whole or separated eggs are mixed for uniformity, filtered to remove chalazae, membranes or bits of shell. Thus prepared egg contents are pasteurized at 60-62oC/3-4 min and filled into suitable container for freezing. Freezing generally is done in a sharp freezer room with circulating air at -30oC. Freezing may take about 48-72h. www.AgriMoon.Com 187 Food Technology-II Egg white and whole egg can be frozen as such without any additives but it is difficult in case of egg yolk. While freezing egg yolk becomes gummy and thick due to gelation. This can be prevented by the addition of 10% sugar or salt or glycerin 5%. Sugar yolk will be used by bakers, confectioners and salted yolk may be used by mayonnaise manufacturers. These ingredients should be dissolved in the yolk during mixing and prior to screening. 27.3.2 Production of spray dried whole egg Fig. 27.2 Process flow gram for spray dried whole egg The whites, Yolks and whole eggs may be dried by several methods, like spray drying, tray drying, foam drying or freeze drying. Egg white contains traces of glucose and galactose which react with egg protein leading to maillard browning. This discolors the dried egg white. Browning can be prevented by removing glucose through fermentation by yeast or with commercial enzymes. This is known as desugaring and this is practiced prior to the drying of all egg white. www.AgriMoon.Com 188 Food Technology-II 27.4 Functional Properties of Egg content Eggs provide many desirable attributes as a food ingredient. The functional properties derived by egg contents are Coagulation, Emulsification and Foam formation. 27.4.1 Coagulation The egg protein coagulates upon heating accompanied by binding of moisture and increase in viscosity. Heating causes denaturation of egg protein and gradually aggregates to form a three dimensional gel network. Thus eggs can be used as thickening agent in many food formulations mainly custards, cakes, pie fillings, cream puddings etc. The coagulation temperature is influenced by pH, salts, other ingredients and duration of heating. Egg white coagulates at 62 – 65oC and egg yolk at 65-70oC. Heat coagulated protein helps to hold the shape of the product in which these are used. Thus eggs are used as binding agent in cutlets, chops etc. 27.4.2 Emulsification The phospholipids i.e. lecithin and certain proteins present in egg acts as an excellent emulsifying agent. In mayonnaise egg yolk acts as an emulsifier to keep oil suspended in vinegar. 27.4.3 Foaming Eggs when beaten form elastic films, which can trap air. Egg and egg products are good foaming agents. They produce large foam volume and relatively stable for cooking. Thus entrapped air expands during baking and gives fluffy and spongy product. Thus eggs are extensively used as leavening agent in baked products such as cakes and muffins. 27.4.4 Quality checks and storage of egg Like any other food product, Eggs start deteriorating soon after it is laid. So it is very important to check the quality of the egg before its consumption. Good quality egg should possess following qualities once it is broken. www.AgriMoon.Com 189 Food Technology-II 1. Yolk is firm and stands up in the centre of white 2. Egg white forms a definite ring around the yolk and thick white holds its shape 3. No blood spots are present 4. No bad odour 27.4.5 Changes occur in egg during storage 1. Increase in the size of air cell due to loss of moisture 2. Increased pH due to escape of carbon dioxide. pH increases from 7.6 to 9.7 3. Percentage of thin white increases, thus egg white loses its shape and runs easily. 4. Water passes from white to yolk, thus fluid content of yolk increases. 27.5 Indicators to Determine Spoilage in Eggs 1. White index: White index = Height of thickest egg white portion/Egg diameter Range: 0.08 – 0.1 2. Yolk Index Yolk index = Height of Yolk/Yolk width Range: 0.35 – 0.45 3. Hough’s Unit (HU) Commonly used index to check the egg quality HU = Height of thick white/weight of Egg www.AgriMoon.Com 190 Food Technology-II For good quality egg HU is 72 and above and HU about 30 to 60 indicates poor quality. 4. Air cell size should be 2-3cm 27.6 Preservation of the Shell Eggs Eggs can be preserved by 4 different methods 27.6.1 Wet immersion method In this method only infertile, fresh, good quality eggs should be used 27.6.1.1 Lime sealing method In this method saturated solution of lime water is used. Eggs are held in lime water for 14 -16hr, during immersion CO2 released from the egg combined with lime to form calcium carbonate which deposits and seals shell pores. Then it is removed and stored at room temperature. Such eggs can be stored for 3 -4 weeks at room temperature 27.6.1.2 Water glass method 10% solution of sodium silicate is commonly called water glass. In this method Water should be boiled and cooled to 24 – 26oC, to remove the dissolved CO2, before the addition of calculated amount of sodium silicate. Eggs are kept overnight and then removed and stored at room temperature. 27.6.2 Dry methods 27.6.2.1 Oiling In this method the quality of eggs is preserved by sealing the shell pores using suitable oil and thus preventing evaporation of water, CO2 and other changes. Oiling can be done by Dip method or Spray method. Oiled eggs can be preserved upto 3 weeks at room temperature. www.AgriMoon.Com 191 Food Technology-II 27.6.2.2 Gaseous atmosphere Modified atmosphere packing of eggs proved to improve its shelf life. Maintenance of higher CO2 pressure surrounding the eggs prevent CO2 loss from the egg thus improves the egg quality. 27.6.3 Thermization or heat treatment methods Fertile, fresh eggs can be preserved by this method. Eggs are thermo- stabilized by immersing it in boiling water for 3 to 5 min while keeping the water stirred constantly. This heat treatment coagulates the albumin very close to the shell and thus prevents CO2 loss. Thermized eggs can be stored at room temperature for 3-4 weeks. 27.6.4 Cold storage or refrigeration: Eggs can be stored well for a long time up to 5 – 6 months at -1.1oC and 85-90% relative humidity. For storage up to 3 – 4 weeks a temperature of -12.8oC and relative humidity of 60-70% is sufficient. *****☺***** www.AgriMoon.Com 192 Food Technology-II Module 8. Fish and its processing Lesson 28 FISH HARVESTING, HANDLING AND TRANSPORTATION; CLASSIFICATION 28.1 Introduction Fish is a source of valuable animal protein and is now considered as a health food. This has resulted in increased consumer demand. Indian fisheries and aquaculture provides nutritional security to the human food and contributes to the agricultural exports and engages very large number of people in different activities. India is the 3rd largest fish producing nations (after Chine and Indonesia) in the world with the production of 7.3 million MT (FAO 2007). Presently, fisheries and aquaculture contribute 1.10 % to the national GDP, and 5.30 % to agriculture and allied activities, while the average annual value of output during the Tenth Five Year Plan (2002-2007) was Rs31, 682.50 crores. 28.1.1 Classification of fisheries Fisheries can be broadly categorized into two types - fin fisheries and non-fin fisheries. Fin fisheries means fisheries of true fishes, whereas non-fin fisheries is the fisheries of organisms other than true fish like prawn, crab, lobster, mussel, oyster, sea cucumbers, frog, sea weeds, etc. Fin fisheries can be further categorized into two types – capture fisheries and culture fisheries. 28.1.1.1 Capture fisheries It is the exploitation of aquatic organisms without stocking the seed. Recruitment of the species occurs naturally. Capture fisheries is carried out in the sea, rivers, reservoirs, etc. Fish yield decreases gradually in capture fisheries due to indiscriminate catching of fish. Capture fisheries practiced in the sea is referred as marine fisheries and Inland capture fisheries if it is in the rivers or reservoirs. www.AgriMoon.Com 193 Food Technology-II 28.1.1.2 Culture fisheries It is the cultivation of selected fishes in confined areas with utmost care to get maximum yield. The seed is stocked, nursed and reared in confined waters and then the crop is harvested. Culture takes place in ponds, which are fertilized and supplementary feeds are provided to fish to get maximum yield. 28.1.2 Fishing techniques Fishing techniques are methods for catching fish. Use of fishing methods varies, depending on the types of fisheries, and can range from as simple process as gathering of aquatic organisms by hand picking to highly sophisticated fish harvesting systems, viz. aimed mid-water trawling or purse seining conducted from large fishing vessels. The targets of capture fisheries can range from small invertebrates to large tunas and whales. 28.1.2.1 Principles of catching fish The large diversity of targets in capture fisheries and their wide distribution requires a variety of fishing gears and methods for efficient harvest. These technologies have been developed around the world according to local traditions and technological advances in various disciplines like hydrodynamics, acoustics and electronics. Filtering the water, luring and outwitting the prey and hunting, are the basis for most of the fishing gears and methods used even today. Harvest technologies, as they are practiced today generally fall into 3 main groups: Catching fish singly or in schools by use of nets or spears Trapping fish in stationary gears such as fish traps or set nets Attracting fish to get caught on hooks by use of bait, artificial lures or other means such as light. www.AgriMoon.Com 194 Food Technology-II 28.1.2.2 Fish harvesting methods Fish harvesting systems includes fishing vessels (craft) and fishing gear. The term fishing vessels is used to denote the mobile floating objects engaged in catching operations. Fishing gear is synonymous for ‘fishing net’ which is used to catch the fish in the water bodies. Most significant among the technological developments which support the evolutions of fish harvest technology are Developments in craft technology and mechanization of propulsion, gear and catch handling, Introduction of synthetic gear materials Developments in acoustic fish detection and satellite based remote sensing techniques, Advances in electronic navigation and position fixing equipment, 28.1.2.3 The traditional methods of fish harvesting Ring seine, Stake net, Chinese dip net, Cast net, Shore seine, Trammel net, Mini trawls, Gill nets, Hook and line, traps and pots 28.1.2.4 Modern methods of fish harvesting Trawling, Purse seining, Hook and line mechanized Jigging and Trolling lines. 28.1.3 Handling of fishes Since fish is highly perishable commodity, it is to be immediately processed into various products to preserve its quality and to increase the shelf life. Fish requires proper handling and preservation to increase its shelf life and retains its nutritional attributes. Fish are particularly prone to rapid pathogenic contamination. The main safety concerns are unhygienic handling during and after fish harvest, insufficient refrigeration, substandard processing and poor packaging. Maintaining the quality of the fish begins with harvest and carries through the harvest to consumption chain. Handling of fish varies with type of the fish, the processing methods and the intended final product. The earliest practice of fish handling in many part of the world is to keep caught fish alive until cooking and consumption. Till today, this remains to be one of the common fish handling practices. www.AgriMoon.Com 195 Food Technology-II For harvested fish, the general handling practices after capture are Transferring catch from gear to vessel Washing/Sorting Bleeding/gutting Chilling Chilled storage and unloading The most important factors to be considered in the initial handling and transport are the temperature, duration of storage/ transport and the hygiene in all respects including that of the handlers. 28.1.3.1 Washing and sorting of fish The harvested fish should be washed well with potable water to free it from dirt and other extraneous matter. Slime accumulating on the skin surface of dying fish is a protection mechanism against harmful conditions. In some freshwater species slime constitutes 2-3% of body weight. Slime excretion stops before rigor mortis; it creates a perfect environment for the growth of micro- organism and should be removed by thorough washing. Water chlorinated at 10ppm level is ideal for initial cleaning. After washing the catch should be sorted species wise and size wise. Bruised, damaged and decomposed fish shall be separated from the catch during sorting. 28.1.3.2 Dressing Dressing operations of the catch include deheading, bleeding and gutting. This has to be carried out as fast as possible without significant bacterial contamination. Gills and viscera harbour several spoilage bacteria in large number. Therefore, where possible, it is advisable to remove the gills and viscera before the fish is preserved and stored. www.AgriMoon.Com 196 Food Technology-II 28.1.3.3 Deheading The head constitutes 10-20% of the total fish weight and it is cut off as an inedible part. Although many mechanized deheading machines had been developed for processing marine fish, freshwater fish are usually deheaded manually. 28.1.3.4 Bleeding When fish dies, the blood in the fish can clot and turn black or brown in color adversely affecting the color and appearance of the meat. Therefore bleeding is done to preserve the quality of the meat. Slitting the throat followed by hanging the fish by tail or slitting the throat and immersing in cold water are the methods for bleeding. 28.1.3.5 Gutting The purpose of gutting is to remove those fish body parts most likely to reduce product quality, as well as to remove gonads and sometimes the swim bladder. Gutting consists of cutting down the belly (fish may be deheaded or not), removal of internal organs, and, optionally, cleaning the body cavity of the peritoneum, kidney tissue and blood. 28.1.3.6 Chilling and storage Decreasing the temperature of the fish to about 0°C slows down the microbiological, chemical and biochemical decomposition processes and extends fish stability. Thus when the raw material is cooled quickly, just after capture, and kept at low temperature during transport, processing and distribution, it meets the basic processing requirements. Its usefulness is extended and at the same time fish quality is maintained. The most common means of chilling is by the use of ice. Ice is available is several forms such as blocks, plates, tubes, shells, soft and flakes. In modern fish processing plants, especially the small ones, flake ice generators dominate as flake ice ensures major contact surface with fish hence higher cooling capacity, low production cost, relatively dry and will not stick together to form clumps when stored. www.AgriMoon.Com 197 Food Technology-II Fish spoil more quickly if It has struggled for long in the net or inboard, than a fish, which is killed quickly. Its stomach is full while catching, It is bruised while catching or handling 28.1.4 Transportation of chilled fish Fish is transported both through air and land. Land transportation of chilled fish is carried out in insulated or mechanically refrigerated vehicles with minimum inside temperature of 70C. Boxes for land transportation are made of wood, aluminum, high density polyethylene, expanded polystyrene or polyurethane. The ideal fish transpiration box should be light weight yet strong enough to withstand the combined weight of fish, ice and stacking and should have good insulating properties. Boxes are usually made of double bottom to collect the melt water. Air shipment of chilled fish requires a lightweight and protective container. Modern insulated containers are made of high-density polypropylene with polyurethane insulation. Instead of ice, pads of nonwoven fabric encapsulating synthetic absorbent powder are used for chilling of air shipped fish. These pads could be soaked in water and deep frozen for use. Plywood boxes insulated with 2.5cm thick foamed polystyrene slabs are found to be more useful to transport fish over longer distances involving duration of 60-80hrs. 28.1.5 Marketing practices The fish marketing is normally done at the collection centers which are mainly situated in the area of fish landing. The fishermen visit the fishing grounds and tend to bring the produce to the nearby market for sale as soon as possible. The fishermen who actually catch fish play only an insignificant role in the disposal of catches. Their role is only to hand over the fish catch to fish merchants at the landing centers for sale. The final distribution and marketing of catch is done by commission agents who step in at this stage. www.AgriMoon.Com 198 Food Technology-II 28.1.5.1 Functions of the fish market Fish markets are bridges between producers and consumers. The following are the functions of the market. 1. All types of fishes are brought together for selling. 2. Transportation of fishes 3. Storage of fishes 4. Business problems can be solved 5. Fishes can be graded here 6. Money transactions take place in markets 7. Time and distance is saved. 28.1.5.2 Types of markets Based on the marketing place, production importance and products, the markets can be classified into the following types. 1. Whole sale market: More amounts of fish comes to this market, then distributed to other types of markets. Whole sale market can be grouped into two types, a. Primary whole sale market: More amount of sale of fish takes place in this market. Collection of the fishes from surrounding places and selling the fish to wholesalers takes place. These types of markets are found either in a village or a place covering a group of villages or towns or cities. These are known as shandies. b. Secondary whole sale market: These are also called as gunjs. The fishes are brought from the primary whole sale markets and sold to the wholesalers. 2. Terminal markets: The fishes are sold to the retailers or consumers or to the agents. www.AgriMoon.Com 199 Food Technology-II 3. Retail markets: The fishes are sold to the consumers by the retailers or wholesalers. 4. Fairs: These are found temporarily during festival times or in fairs. The fishes are sold directly to consumers. *****☺***** www.AgriMoon.Com 200 Food Technology-II Module 8. Fish and its processing Lesson 29 PROCESSING AND PRESERVATION OF FISH; VALUE ADDED FISHERY PRODUCTS 29.1 Introduction Fish, however, is more susceptible to spoilage than certain other animal protein foods, such as meat and eggs. To prevent spoilage of fish, some form of preservation is necessary. Preservation means keeping the fish, after it has landed, in a condition wholesome and fit for human consumption for a short period to few days or for longer periods of over few months. During the period of preservation the fish is kept as ‘fresh’ as possible, with minimum losses in flavour, taste, odor, form, nutritive value, weight and digestibility of flesh. This preservation should cover the entire period from the time of capture of fish to its sale at the retailer’s counter. 29.2 Methods of Preservation Preservation can be done, both for short and long duration 29.2.1 Preservation for short duration 29.2.1.1 Chilling This is obtained by covering the fish with layers of ice. Ice is effective for short term preservation such as is needed to transport landed fish to nearby markets or to canning factories, etc. Here autolytic enzyme activities are checked by lowering the temperature. 29.2.2 Preservation for long time When the preservation is required for a long period of time, the fishes are passed through the cleaning, gutting and conservation and storage. 29.2.2.1 Cleaning and gutting During cleaning, the caught first are fish washed thoroughly in cold, clean water to remove bacteria, slime, blood, faeces, and mud, etc. from the body surface of the fish. It is being done under proper sanitary www.AgriMoon.Com 201 Food Technology-II conditions. Large fishes are gutted (i.e. all the internal organs or viscera are removed) and the body cavity is washed. 29.3 Conservation and storage Conservation is necessary to keep the dead fish in fresh condition for quite a long time. This is achieved by employing any one of the methods like freezing, drying, salting, smoking and canning. 29.3.1 Freezing Freezing means removal of heat from the body. To check the enzymal, bacterial action and putrefaction it is preferred to store the fish under lower temperatures. When fish is intended to be stored for a long period, quick freezing is preferred which inhibits bacterial action. During quick freezing every part of the product comes within the range of 0o to -5oC. Properly frozen fish at -20oC retains its physical properties and nutritive values for a year or more and is almost as good as fresh fish. There are three ways effecting quick freezing: a) Direct immersion of fish in the refrigerating medium, b) Indirect contact with the refrigerant through plates c) Forced convection of refrigerated air directed at heat transfer surfaces. In general different methods of freezing are adapted through sharp freezer, air blast freezer, contact plate freezer, immersion freezing, liquid freon freezing, liquid nitrogen freezing, fluidized bed freezer, cryogenic freezing, etc. Among the various types of quick freezing plants installed in India the carrier air blast type is widely used. The air blast freezer is in the form of a tunnel and heat transfer is affected rapidly by the circulation of air. The temperature used ranges from 0 to -30oC and air velocity varies from 30 to 1050 meters/min. 29.3.2 Freeze drying This is modified deep freezing, completely eliminating all chances of denaturation. The deep frozen fish at -20oC is then dried by direct sublimation of ice to water vapour with any melting into liquid water. This is achieved by exposing the frozen fish to 140oC in a vacuum chamber. The fish is then packed or canned in dried condition. The product is quite fresh looking in appearance, flavour, colour and quality. www.AgriMoon.Com 202 Food Technology-II 29.3.3 Salting Salting is a process where the common salt, sodium chloride, is used as a preservative which penetrates the tissues, thus checks the bacterial growth and inactivates the enzymes. Some of the factors involved in salting of fish which play an important role are purity of salt, quantify of salt used, method of salting and weather conditions like temperature, etc. During the process the small fishes are directly salted without being cleaned. In the medium and large sized fish the head and viscera are removed and longitudinal cuts are made with the help of knives in the fleshy area of the body. Then the fish is washed and filled with salt for uniform penetration through flesh. Large fishes like sharks are cut into convenient sized pieces. Generally, sardines, mackerels, seer fishes, cat fishes, sharks and prawns are used for salting. Dry salting and wet salting and are the methods employed in salting of fish. a) Dry salting In this process the fish is first rubbed in salt and packed in layers in the tubs and cemented tanks. The salt is applied in between the layers of fishes in the proportion of 1:3 to 1:8 salt to fish. The proportion of salt to fish varies with the fish since the oily fish require more salt. At the end of 10 - 24 hours the fishes are removed from the tubs and washed in salt brine and dried in the sun for 2 or 3 days. b) Wet salting The cleaned fish are put in the previously prepared concentrated salt solution. It is stirred daily till it is properly picked. With large sized fishes, longitudinal slits are made in the flesh to allow penetration of salt. After pickling for 7-10days, the salty water that oozes out from the fish is allowed to drain off. This can be stored upto 3-4months. 29.3.4 Smoking In this method, landed fish is cleaned and brined. It is then exposed to cold or hot smoke treatment. In cold smoking, first a temperature of 38oC is raised from a smokeless fire. After this heating, cold smoke at a temperature below 28oC is allowed to circulate past the fish. In case of hot smoking, first a strong fire produces a temperature around 130oC.This is followed by smoking at a temperature of 40oC. The smoke has to be wet and dense. Good controls are necessary over density, temperature, humidity, speed of circulation, pattern of circulation and time of contact with fish of the smoke. The phenol content of the www.AgriMoon.Com 203 Food Technology-II smoke acts as an antiseptic and it also imparts a characteristic colour and flavour. For making fire and smoke, only hard wood (Conifer wood, Saw dust etc.) are used. 29.3.5 Canning Canning is a method of preservation in which spoilage can be averted by killing micro-organisms through heat. Oily fish are the most suitable for canning. Salmon, tuna, sardine, herring, lobster, shrimp, etc. are canned. The raw material should be processed properly since it contains most dangerous Clostridium botulinum which should be destroyed. There are some other heat resistant bacteria like Clostridium sporogenes which can be eliminated at a temperature of 5 - 6 times more than Clostridium botulinum. It needs a temperature of 120oC for 4 minutes or at 115oC for 10 minutes to kill them in large numbers. Canning is done by putting cleaned dressed and cut fish into a saline solution. The cans holding the fish and the saline are then double seamed under vacuum. Thereafter, sterilization of cans takes place at 121oC for 90min under steam pressure. Sterilization is followed by cooling of the cans under room temperature by running water. 29.3.6 Drying Drying involves dehydration i.e. the removal of moisture contents of fish, so that the bacterial decomposition or enzymic autolysis does not occur. When moisture contents reduce upto 10%, the fishes are not spoiled provided they are stored in dry conditions. Fish drying is achieved either naturally or by artificial means. In natural drying the fishes after being caught are washed and dried in the sunshine. In artificial drying the killed fishes are cleaned, gutted and have their heads removed. They are then cut lengthwise to remove large parts of their spinal column, followed by washing and drying them mechanically. 29.4 Value Added Fisheries Products Value addition is one of the most practical ways to increase the profitability in fish processing and sale in domestic as well as international markets. It is also becoming a market requirement as the wholesale traders, retail outlets and finally the consumers are on the lookout for fish products that require minimum preparation. Some of the value added fish products are Fish sausages, Fish fillets, Fish cutlets, dehydrated fish products, Fish pickles, Fish flakes/wafers, Fish noodles. Some are described below. www.AgriMoon.Com 204 Food Technology-II 29.4.1 Fish sausages Fish sausage is the ground fish meat with various ingredients (additives) like salt, sugar, starch, spices, fat, chemicals, etc., packed in a synthetic casing, properly sealed, boiled and cooled product. In other words fish sausage is a ready to eat proteinacious food which is heat processed. 29.4.1.1 Recipe Ingredients Percentage 1. Minced fish meat 70.0% 2. Salt 2.0% 3. Sugar 1.5% 4. Polyphosphate 2.0% 5. Spices 1.0% a) Coriander 0.3% b) Chilli powder 0.3% c) Pepper 0.2% d) Garlic 0.1% e) Ginger 0.1% 6. Mono Sodium Glutamate 0.2% 7. Preservatives 0.2% 8. 5% colour solution 0.13% a) 2 % of carmosine www.AgriMoon.Com 205 Food Technology-II b) 3% of ponceau – 4R 9. Starch 9.0% 10. Cold water 10.0% 11. Fat / Vegetable Oil 5.0% 29.4.1.2 Method of preparation Fig. 29.1 Method of preparation www.AgriMoon.Com 206 Food Technology-II 29.4.2 Dehydrated fish products Value added dehydrated fish products available in the market are fish protein concentrate, fish soup powder, fish chutney powder etc. 29.4.3 Preparation of fish protein concentrate (FPC) Fish protein concentrate (FPC) is collective term used for dried fish powders, which contain comparatively little fat. Three grades of FPC available are: 1. FPC type C - fish meal (used for animal consumption). 2. FPC type B - fish meal of standard quality prepared mainly for human consumption. This has a strong taste and flavour of fish. Hence its use was restricted to countries where dried fish is common in their diet. 3. FPC type A - high quality FPC used for human consumption. Solvents are used to remove lipids. It has only 0.05 –0.75% lipid. 29.4.3.1 Method of preparation Fig. 29.2 Method of preparation www.AgriMoon.Com 207 Food Technology-II 29.4.4 Preparation of fish pickle ‘Pickling’ is one of the safest means of preservation of fish. Pickles prepared from fish are gaining acceptance in recent days, since they add to the palatability to starch based bland tasting Asian dishes; besides being nutritious. Fish pickles are good appetizers too. At present there is an expanding export and domestic market for fish pickles. It is prepared by cutting the edible portion of the fish into small pieces, followed by deep frying in vegetable oil and are subsequently mixed with vinegar and salt for preservation, along with fried condiments and species for flavour development. The material is then generally kept for a minimum of 24 hrs for maturing before packing. This is a traditional product of the country and is now gaining popularity. Fig. 29.3 Method of preparation 29.5 Other Value Added Fishery Products 29.5.1 Fish cakes www.AgriMoon.Com 208 Food Technology-II Tuna and mackerels are used commonly to prepare fish cakes. Fishes are cleaned and steam boiled, then separated in layers. Potatoes are boiled with salt, pepper and citric acid. Layered fish are mixed with the above mixture and packed in vacuum to prepare fish cakes. 29.5.2 Fish salads The fishes are cleaned and pieces are boiled with steam. The boiled fish or prawns are mixed with tomatoes, salt, garlic, maida, pepper and oil to prepare fish salad. This can be used in fresh condition or can be stored. 29.5.3 Fish flakes/wafers Thread fin breams and cat fishes are used in the preparation of flakes or wafers. Fish flesh is boiled, and then mixed with maida, salt, etc. to prepare flakes or wafers. *****☺***** www.AgriMoon.Com 209