Food Technology 1 - PDF

Food Technology 2 Dr. Yanl AlLbawarshi 1  made by Echo https://t.me/mkfrbot Page (1) Food technology 1 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬1 ‫ﻨﻮﻟﻮﺟﻴﺎ اﻷﻏﺬﻳﺔ‬‫ﺗ‬ Page (1)  S...

Food Technology 2 Dr. Yanl AlLbawarshi 1  made by Echo https://t.me/mkfrbot Page (1) Food technology 1 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬1 ‫ﻨﻮﻟﻮﺟﻴﺎ اﻷﻏﺬﻳﺔ‬‫ﺗ‬ Page (1)  Spoilage due to Enzymatic Activity Enzymes are complex chemical substances, which are present in all living organisms and tissues, which control essential metabolic processes. Different biochemical reactions in foods and plants tissues are catalysed by enzymes. Enzymatic spoilage is the greatest cause of food deterioration. They are responsible for certain undesirable or desirable changes in fruits, vegetables and other foods. Examples involving endogenous enzymes include: 1- polyphenol oxidases (PPO), phenolases. 2- Peroxidase, Catalase, Lipooxygenase 3- pectic enzyme 4- lipase 5- amylase Dr. Yanl AlLbawarshi 2  made by Echo https://t.me/mkfrbot Page (2) 2 What is Food Science and food technology? Food Science is the discipline in which biology, physical sciences, and engineering are used to study the nature of foods, the causes of their deterioration, and the principles underlying food processing. ‫ واﻟﻬﻨﺪﺳﺔ‬، ‫ اﻻﻧﻀﺒﺎط اﻟﺬي ﺗﻘﻮم ﻓﻴﻪ ﻋﻠﻢ اﻷﺣﻴﺎء واﻟﻌﻠﻮم اﻟﻔﻴﺰﻳﺎﺋﻴﺔ‬‫ﻨﻮﻟﻮﺟﻴﺎ اﻷﻏﺬﻳﺔ؟ ﻋﻠﻮم اﻷﻏﺬﻳﺔ ﻫ‬‫ ﻋﻠﻮم اﻷﻏﺬﻳﺔ وﺗ‬‫ ﻣﺎ ﻫ‬2.‫ﺎﻣﻨﺔ ﻣﻌﺎﻟﺠﺔ اﻷﻏﺬﻳﺔ‬‫ واﻟﻤﺒﺎدئ اﻟ‬، ‫ أﺳﺒﺎب ﺗﺪﻫﻮرﻫﻢ‬، ‫ﺗﺴﺘﺨﺪم ﻟﺪراﺳﺔ ﻃﺒﻴﻌﺔ اﻷﻃﻌﻤﺔ‬ Food Technology is the application of food science to the selection, preservation, processing, packaging, distribution, and use of safe, nutritious, and wholesome food. Yanal ALbawarshi ‫ واﺳﺘﺨﺪام ﻃﻌﺎم آﻣﻦ وﻣﻐﺬي‬، ‫ اﻟﺘﻮزﻳﻊ‬، ‫ اﻟﺘﻐﻠﻴﻒ‬، ‫ اﻟﻤﻌﺎﻟﺠﺔ‬، ‫ اﻟﺤﻔﻆ‬، ‫ اﻻﺧﺘﻴﺎر‬‫ ﺗﻄﺒﻴﻖ ﻋﻠﻮم اﻷﻏﺬﻳﺔ ﻋﻠ‬‫ﻨﻮﻟﻮﺟﻴﺎ اﻷﻏﺬﻳﺔ ﻫ‬‫ﺗ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬.‫وﺻﺤ‬ Page (2)  the post-harvest senescence and spoilage of fruit and vegetables; oxidation of phenols in plant tissues to orthoquinones by phenolases, peroxidases and polyphenol oxidases (PPO). These orthoquinones rapidly polymerize to form brown pigments known as melanin leading to enzymic browning; sugar – starch conversion in plant tissues by amylases; post-harvest demethylation of pectic substances in plant tissues (leading to softening of plant tissues during ripening, and firming of plant tissues during processing). If enzymatic reactions are uncontrolled, the off-odours, and off-colors may develop in foods. Dr. Yanl AlLbawarshi 3  made by Echo https://t.me/mkfrbot Page (3) QUALITY people choose foods based on a number of factors which can in sum be thought of as "quality. “ Quality has been defined as degree of excellence and includes such things as taste, appearance, and nutritional content. Quality and price need not go together ‫ أﻧﻬﺎ‬‫ ﺗﻢ ﺗﻌﺮﻳﻒ اﻟﺠﻮدة ﻋﻠ‬."‫ﻌﺘﻘﺪ أﻧﻪ "اﻟﺠﻮدة‬‫ﻦ ﺑﺎﺧﺘﺼﺎر ﻳ‬‫ ﻳﻤ‬‫ ﻋﺪد ﻣﻦ اﻟﻌﻮاﻣﻞ اﻟﺘ‬‫ ﻋﻠ‬‫ﺟﻮدة ﻳﺨﺘﺎر اﻷﺷﺨﺎص اﻷﻃﻌﻤﺔ ﺑﻨﺎء‬ ‫ﺎ‬‫ ﻻ ﺗﺤﺘﺎج اﻟﺠﻮدة واﻟﺴﻌﺮ ﻣﻌ‬.‫درﺟﺔ ﻣﻦ اﻟﺘﻤﻴﺰ وﺗﺸﻤﻞ أﺷﻴﺎء ﻣﺜﻞ اﻟﺬوق واﻟﻤﻈﻬﺮ واﻟﻤﺤﺘﻮى اﻟﻐﺬاﺋ‬ 3 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺒﺎرﺷ‬3 Page (3)  Factors Affecting the Postharvest Quality of Fruits and Vegetables Two types of factors are involved in the postharvest quality of fruits and vegetables. They are biological or internal factors and environmental or external factors. 1 Biological factors a. Respiration rate Even after harvesting fruits and vegetables behave as living commodity (entity) and continues to respire. C6H12O6 + 6O2 6CO2 + 6H2O + 673 K.cal Dr. Yanl AlLbawarshi 4  made by Echo https://t.me/mkfrbot Page (4) "value" is thought of as a composite of cost and quality. More expensive foods can be a good value if their quality is very high. The nutrient value of the different grades of canned fruits and vegetables is similar for all practical purposes, yet the price can vary as much as threefold depending on other attributes of.‫ﻠﻔﺔ ﻗﻴﻤﺔ ﺟﻴﺪة إذا ﻛﺎﻧﺖ ﺟﻮدﺗﻬﺎ ﺟﺪًا ﻋﺎﻟ‬‫ﻮن اﻷﻃﻌﻤﺔ اﻷﻛﺜﺮ ﺗ‬‫ﻦ أن ﺗ‬‫ ﻳﻤ‬.‫ﻠﻔﺔ واﻟﺠﻮدة‬‫ﻌﺘﻘﺪ أن "اﻟﻘﻴﻤﺔ" ﻣﺮﻛﺐ ﻣﻦ اﻟﺘ‬‫ ﻳ‬ ‫ﻮن‬‫ﻦ أن ﻳ‬‫ وﻣﻊ ذﻟﻚ ﻳﻤ‬، ‫اﻟﻘﻴﻤﺔ اﻟﻤﻐﺬﻳﺔ ﻟﻠﺪرﺟﺎت اﻟﻤﺨﺘﻠﻔﺔ ﻣﻦ اﻟﻔﻮاﻛﻪ اﻟﻤﻌﻠﺒﺔ و اﻟﺨﻀﺮوات ﻣﺘﺸﺎﺑﻬﺔ ﻟﺠﻤﻴﻊ اﻷﻏﺮاض اﻟﻌﻤﻠﻴﺔ‬ ‫ ﺳﻤﺎت أﺧﺮى‬‫ا ﻋﻠ‬‫ ﺛﻼﺛﺔ أﺿﻌﺎف اﻋﺘﻤﺎد‬‫اﻟﺴﻌﺮ ﺗﺨﺘﻠﻒ ﻣﺎ ﻳﺼﻞ إﻟ‬ quality. This is why processors will go to extremes to control quality. 4 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬4.‫ اﻟﺠﻮدة‬‫ اﻟﺤﺪود ﻟﻠﺴﻴﻄﺮة ﻋﻠ‬‫ أﻗﺼ‬‫ أن اﻟﻤﻌﺎﻟﺠﺎت ﺳﺘﺬﻫﺐ إﻟ‬‫ ﻫﺬا ﻫﻮ اﻟﺴﺒﺐ ﻓ‬.‫ﺟﻮدة‬ Page (4)  Fruits, on the basis of their respiration pattern during ripening, can be classified as either 1- climacteric or 2- non-climacteric. Non-climacteric fruits are not capable of continuing their ripening process once removed from the plant e.g. dates, grapes, pineapple, lemon, lime, pomegranate, etc. while climacteric fruits can be harvested mature and ripened off the plant e.g. apple, papaya, banana, mango, guava, etc. Dr. Yanl AlLbawarshi 5  made by Echo https://t.me/mkfrbot Page (5) When we select foods and when we eat, we use all of our physical senses, including sight, touch, smell, taste, and even hearing. The snap of a potato chip, the crackle of a breakfast cereal, and crunch of celery are textural characteristics, but we also hear them. ‫ وﺣﺘ‬، ‫ اﻟﺬوق‬، ‫ اﻟﺮاﺋﺤﺔ‬، ‫ اﻟﻠﻤﺲ‬، ‫ ذﻟﻚ اﻟﺒﺼﺮ‬‫ ﺑﻤﺎ ﻓ‬، ‫ ﻧﺴﺘﺨﺪم ﺟﻤﻴﻌﻨﺎ اﻟﺤﻮاس اﻟﺠﺴﺪﻳﺔ‬، ‫ ﻋﻨﺪﻣﺎ ﻧﺨﺘﺎر اﻷﻃﻌﻤﺔ وﻋﻨﺪﻣﺎ ﻧﺄﻛﻞ‬.‫ﺎ اﺳﻤﻌﻬﻢ‬‫ﻨﻨﺎ أﻳﻀ‬‫ ﻟ‬، ‫ ﺧﺼﺎﺋﺺ ﻧﺼﻴﺔ‬‫ ﻫ‬Crunch of Celery ‫ و‬، ‫ ﺧﺸﺐ ﺣﺒﻮب اﻹﻓﻄﺎر‬، ‫ اﻟﻤﻔﺎﺟﺌﺔ ﻟﺮﻗﺎﻗﺔ اﻟﺒﻄﺎﻃﺲ‬.‫ﺳﻤﻊ‬ Food quality detectable by our senses can be divided into three main categories: 1 - appearance factors, 2 - textural factors, and 3 - flavor factors. 5 Yanal ALbawarshi ‫ ‐ اﻟﻌﻮاﻣﻞ‬2 ، ‫ ‐ ﻋﻮاﻣﻞ اﻟﻤﻈﻬﺮ‬1 :‫ ﺛﻼث ﻓﺌﺎت رﺋﻴﺴﻴﺔ‬‫ﻦ اﻛﺘﺸﺎﻓﻬﺎ ﺑﻮاﺳﻄﺔ ﺣﻮاﺳﻨﺎ إﻟ‬‫ ﻳﻤ‬‫ﻦ ﺗﻘﺴﻴﻢ ﺟﻮدة اﻟﻄﻌﺎم اﻟﺘ‬‫ ﻳﻤ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬5.‫ﻬﺔ‬‫ ‐ ﻋﻮاﻣﻞ اﻟﻨ‬3 ‫ و‬، ‫اﻟﻨﺼﻴﺔ‬ Page (5) Fig. 6.1 Respiration pattern in climacteric (e.g. tomato) and non- climacteric (orange) fruits Dr. Yanl AlLbawarshi 6  made by Echo https://t.me/mkfrbot Page (6) ADDITIONAL QUALITY FACTORS Three very important quality factors that may not always be apparent by sensory observation are nutritional quality, sanitary quality, and keeping quality. 1 - Nutritional quality frequently can be assessed by chemical or instrumental analyses for specific nutrients. ‫ اﻟﺠﻮدة‬، ‫ ﺟﻮدة ﻏﺬاﺋﻴﺔ‬‫ﺎ ﻣﻦ ﺧﻼل اﻟﻤﻼﺣﻈﺔ اﻟﺤﺴﻴﺔ ﻫ‬‫ﻮن داﺋﻤ‬‫ﻋﻮاﻣﻞ ﺟﻮدة إﺿﺎﻓﻴﺔ ﺛﻼﺛﺔ ﻋﻮاﻣﻞ ﺟﻮدة ﻣﻬﻤﺔ ﺟﺪًا ﻗﺪ ﻻ ﺗ‬ ‫ﻴﻤﻴﺎﺋﻴﺔ أو ﺗﺤﻠﻴﻼت‬‫ ﻛﺜﻴﺮ ﻣﻦ اﻷﺣﻴﺎن ﻋﻦ ﻃﺮﻳﻖ اﻟﻤﻮاد اﻟ‬‫ﻦ ﺗﻘﻴﻴﻢ اﻟﺠﻮدة اﻟﺘﻐﺬوﻳﺔ ﻓ‬‫ ‐ ﻳﻤ‬1.‫ اﻟﺠﻮدة‬‫ واﻟﺤﻔﺎظ ﻋﻠ‬، ‫اﻟﺼﺤﻴﺔ‬.‫ﻣﻔﻴﺪة ﻟﻤﻐﺬﻳﺎت ﻣﺤﺪدة‬ 2 - Sanitary quality usually is measured by counts of bacteria, yeast, mold, and insect fragments, as well as by sediment levels. 6 Yanal ALbawarshi.‫ وﻛﺬﻟﻚ ﺑﺎﻟﺮواﺳﺐ ﻣﺴﺘﻮﻳﺎت‬، ‫ ﺷﻈﺎﻳﺎ اﻟﺨﻤﻴﺮة واﻟﻌﻔﻦ واﻟﺤﺸﺮات‬، ‫ﺘﻴﺮﻳﺎ‬‫ ‐ ﻋﺎدة ﻣﺎ ﻳﺘﻢ ﻗﻴﺎس اﻟﺠﻮدة اﻟﺼﺤﻴﺔ ﻋﻦ ﻃﺮﻳﻖ ﺗﻬﻢ اﻟﺒ‬2 ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬6 Page (6) Fig. 6.2 Respiration rate of a climacteric fruit during different stages of growth Dr. Yanl AlLbawarshi 7  made by Echo https://t.me/mkfrbot Page (7) 3 - Keeping quality or storage stability is measured under storage and handling conditions that are set up to simulate or somewhat exceed the conditions the product is expected to encounter in normal distribution and use. 7 Yanal ALbawarshi ‫ ﺣﺪ ﻣﺎ اﻟﻈﺮوف‬‫ ﺗﻢ إﻋﺪادﻫﺎ ﻟﻤﺤﺎﻛﺎة أو ﻳﺘﺠﺎوز إﻟ‬‫ ‐ ﻳﺘﻢ ﻗﻴﺎس اﻟﺠﻮدة أو اﺳﺘﻘﺮار اﻟﺘﺨﺰﻳﻦ ﺗﺤﺖ ﻇﺮوف اﻟﺘﺨﺰﻳﻦ واﻟﻤﻨﺎوﻟﺔ اﻟﺘ‬3 ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬7.‫ واﻻﺳﺘﺨﺪام‬‫ اﻟﺘﻮزﻳﻊ اﻟﻄﺒﻴﻌ‬‫ ﻣﻦ اﻟﻤﺘﻮﻗﻊ أن اﻟﻤﻨﺘﺞ ﻣﻮاﺟﻬﺔ ﻓ‬‫اﻟﺘ‬ Page (7)  Environmental factors a. Temperature Temperature is the most important environmental factor that influences the deterioration rate of harvested fruits and vegetables, for each increase of 10 C above the optimum temperature, the rate of deterioration increases by two- or three-fold. The term Q10 if often used to denote the ratio of reaction rates with 10 C rise in temperature Dr. Yanl AlLbawarshi 8  made by Echo https://t.me/mkfrbot Page (8) Food Preservation and Storage Introduction Food is the basic necessity of life and is invaluable for healthy existence of human beings. Most of our food consists of agricultural and livestock products, which are usually seasonal and spoil quickly. ‫ ﻣﻌﻈﻢ ﻃﻌﺎﻣﻨﺎ‬.‫ اﻷﻏﺬﻳﺔ وﺗﺨﺰﻳﻨﻬﺎ ﻣﻘﺪﻣﺔ اﻟﻐﺬاء ﻫﻮ اﻟﻀﺮورة اﻷﺳﺎﺳﻴﺔ ﻟﻠﺤﻴﺎة وﻫﻮ ﻻ ﻳﻘﺪر ﺑﺜﻤﻦ ﻟﻠﺼﺤﺔ وﺟﻮد اﻟﺒﺸﺮ‬‫اﻟﺤﻔﺎظ ﻋﻠ‬.‫ﻮن ﻣﻮﺳﻤﻴﺔ وﻳﻨﻔﺪ ﺑﺴﺮﻋﺔ‬‫ ﻋﺎدة ﻣﺎ ﺗ‬‫ واﻟﺘ‬، ‫ﻮن ﻣﻦ اﻟﻤﻨﺘﺠﺎت اﻟﺰراﻋﻴﺔ واﻟﻤﺎﺷﻴﺔ‬‫ﻳﺘ‬ Foods gradually undergo deterioration or spoilage from the time they are harvested, caught, slaughtered or manufactured unless it is preserved. Deterioration of food in some cases is accompanied by production of toxic substances while in other cases it results in losses of nutritional value. 8 Yanal ALbawarshi ‫ﻦ ﻳﺘﻢ اﻟﺤﻔﺎظ‬‫ ﺗﺨﻀﻊ اﻷﻃﻌﻤﺔ ﺗﺪرﻳﺠﻴﺎً ﺗﺪﻫﻮر أو ﺗﻠﻒ ﻣﻦ اﻟﻮﻗﺖ ﻳﺘﻢ ﺣﺼﺎدﻫﻢ أو ﺗﻢ اﻟﻘﺒﺾ ﻋﻠﻴﻬﻢ أو ذﺑﺤﻬﻢ أو ﺗﺼﻨﻴﻌﻬﻢ ﻣﺎ ﻟﻢ ﻳ‬ ‫ ﻓﻘﺪان اﻟﻘﻴﻤﺔ‬‫ ﺗﺆدي إﻟ‬‫ ﻏﻴﺮﻫﺎ اﻟﺤﺎﻻت اﻟﺘ‬‫ ﺑﻌﺾ اﻟﺤﺎﻻت ﻫﻮ ﻳﺮاﻓﻘﻪ إﻧﺘﺎج اﻟﻤﻮاد اﻟﺴﺎﻣﺔ أﺛﻨﺎء وﺟﻮده ﻓ‬‫ ﺗﺪﻫﻮر اﻟﻄﻌﺎم ﻓ‬.‫ﻋﻠﻴﻪ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬8.‫اﻟﻐﺬاﺋﻴﺔ‬ Page (8) Pectic substances nomenclature Protopectin (insoluble) Immature plant material Pectinic acid (colloidal and soluble) mature plant material Pectin mature plant material Pectic acid Overmature plant material Dr. Yanl AlLbawarshi 9  made by Echo https://t.me/mkfrbot Page (9) it is essential to possess knowledge of processing and preservation methods that produce/ preserve best possible foods over a long period of time with minimum loss of nutritive value. 9 Yanal ALbawarshi ‫ ﻣﺪى ﻓﺘﺮة ﻃﻮﻳﻠﺔ ﻣﻦ‬‫ﻦ اﻷﻃﻌﻤﺔ ﻋﻠ‬‫ أﻓﻀﻞ ﻣﺎ ﻳﻤ‬‫ اﻟﺤﻔﺎظ ﻋﻠ‬/‫ ﺗﻨﺘﺞ‬‫ ﻣﻦ اﻟﻀﺮوري اﻣﺘﻼك ﻣﻌﺮﻓﺔ اﻟﻤﻌﺎﻟﺠﺔ و ﻃﺮق اﻟﺤﻔﻆ اﻟﺘ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬9.‫ ﻗﻴﻤﺔ‬‫ ﻣﻦ ﻓﻘﺪان اﻟﻐﺬاﺋ‬‫اﻟﺰﻣﻦ ﻣﻊ اﻟﺤﺪ اﻷدﻧ‬ Page (9)  Pectic enzyme 1- Protopectin protopectinase pectinic acid 2- pectinesterase 3- Pectin polygalacturonase Dr. Yanl AlLbawarshi 10  made by Echo https://t.me/mkfrbot Page (10) Definition of Food Storage Food storage is the process in which both cooked and raw materials are stored in appropriate conditions for future use without any entry or multiplication of microorganisms. Types of Storage Different foods need different types of storage. ‫ اﻟﻈﺮوف اﻟﻤﻨﺎﺳﺒﺔ ﻟﻼﺳﺘﺨﺪام ﻓ‬‫ ﺗﻢ ﻃﻬﻴﻬﺎ وﺧﺎم ﻳﺘﻢ ﺗﺨﺰﻳﻦ اﻟﻤﻮاد ﻓ‬‫ ﺗﻌﺮﻳﻒ ﺗﺨﺰﻳﻦ اﻟﻄﻌﺎم ﺗﺨﺰﻳﻦ اﻟﻄﻌﺎم ﻫﻮ اﻟﻌﻤﻠﻴﺔ اﻟﺘ‬ ‫ أﻧﻮاع ﻣﺨﺘﻠﻔﺔ ﻣﻦ‬‫ أﻧﻮاع اﻟﺘﺨﺰﻳﻦ اﻷﻃﻌﻤﺔ اﻟﻤﺨﺘﻠﻔﺔ ﺗﺤﺘﺎج إﻟ‬.‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ‬‫اﻟﻤﺴﺘﻘﺒﻞ ﺑﺪون أي دﺧﻮل أو ﻣﻀﺎﻋﻔﺔ اﻟ‬.‫اﻟﺘﺨﺰﻳﻦ‬ There are basically two types of storage, 1 -dry storage and 2 - low temperature. These are further classified on the basis of storage temperature required for different foods. 10 Yanal ALbawarshi ‫ ﻋﻠ‬‫ﻞ إﺿﺎﻓ‬‫ ﻳﺘﻢ ﺗﺼﻨﻴﻒ ﻫﺬه ﺑﺸ‬.‫ ‐ درﺟﺔ ﺣﺮارة ﻣﻨﺨﻔﻀﺔ‬2 ‫ و‬Dry Storage- 1 ، ‫ اﻷﺳﺎس ﻧﻮﻋﺎن ﻣﻦ اﻟﺘﺨﺰﻳﻦ‬‫ ﻳﻮﺟﺪ ﻓ‬ ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬10.‫أﺳﺎس ﻣﻦ درﺟﺔ ﺣﺮارة اﻟﺘﺨﺰﻳﻦ اﻟﻤﻄﻠﻮﺑﺔ ﻟﻸﻃﻌﻤﺔ اﻟﻤﺨﺘﻠﻔﺔ‬ Page (10) Dr. Yanl AlLbawarshi 11  made by Echo https://t.me/mkfrbot Page (11) 1 - Dry storage is meant for longer holding of non - and semi -perishable foods , the latter being stored for a shorter time. It is the space designed for the storage of foods usually at room temperatures ranging between 20 -25 °C with the relative humidity maintained at 60 -65 percent. 2 - Low temperature storage is further divided into three types based on temperature requirement. ‫ إﻧﻬﺎ اﻟﻤﺴﺎﺣﺔ‬.‫ ﻳﺘﻢ ﺗﺨﺰﻳﻦ اﻷﺧﻴﺮ ﻟﻔﺘﺮة أﻗﺼﺮ‬، ‫ ‐ اﻟﺘﺨﺰﻳﻦ اﻟﺠﺎف ﻣﺨﺼﺺ ﻟﻼﺣﺘﻔﺎظ أﻃﻮل ﻟﻸﻃﻌﻤﺔ ﻏﻴﺮ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻄﺒﻴﻖ‬1 ‫ ﻳﺘﻢ اﻟﺤﻔﺎظ‬‫ درﺟﺔ ﻣﺌﻮﻳﺔ ﻣﻊ اﻟﺮﻃﻮﺑﺔ اﻟﻨﺴﺒﻴﺔ اﻟﺘ‬25 ‫ إﻟ‬20 ‫ درﺟﺎت ﺣﺮارة اﻟﻐﺮﻓﺔ ﺗﺘﺮاوح ﺑﻴﻦ‬‫اﻟﻤﺼﻤﻤﺔ ﻟﺘﺨﺰﻳﻦ اﻷﻃﻌﻤﺔ ﻋﺎدة ﻓ‬.‫ أﺳﺎس ﻣﺘﻄﻠﺒﺎت درﺟﺔ اﻟﺤﺮارة‬‫ ﺛﻼﺛﺔ أﻧﻮاع ﻋﻠ‬‫ ‐ ﻳﺘﻢ ﺗﻘﺴﻴﻢ ﺗﺨﺰﻳﻦ درﺟﺔ اﻟﺤﺮارة اﻟﻤﻨﺨﻔﻀﺔ إﻟ‬2.‫ اﻟﻤﺌﺔ‬‫ ﻓ‬65-60 ‫ﻋﻠﻴﻬﺎ ﻋﻨﺪ‬ – Refrigerated storage is a storage space maintained at temperature between 3 to 10 °C. It is used to store perishable foods for short term say 3 -5 days. Milk, meat, fish, poultry and eggs are generally stored under refrigerated storage. – Cold storage is one in which temperature is maintained between 0 and 3 °C. Such storage spaces are also called as chill rooms. These can hold perishables over a week and in the case of fruits and vegetables, even up to a month depending upon variety and stage of ‫ ﻳﺴﺘﺨﺪم‬‫ ﻫﻮ ‐ ﻫ‬.‫ درﺟﺎت ﻣﺌﻮﻳﺔ‬10 ‫ إﻟ‬3 ‫‐ اﻟﺘﺨﺰﻳﻦ اﻟﻤﺒﺮد ﻫﻮ ﻣﺴﺎﺣﺔ ﺗﺨﺰﻳﻦ ﻳﺘﻢ اﻟﺤﻔﺎظ ﻋﻠﻴﻬﺎ ﻋﻨﺪ درﺟﺔ ﺣﺮارة ﺗﺘﺮاوح ﺑﻴﻦ‬ ‫ اﻟﺤﻠﻴﺐ واﻟﻠﺤﻮم واﻷﺳﻤﺎك واﻟﺪواﺟﻦ و ﻳﺘﻢ ﺗﺨﺰﻳﻦ‬.‫ أﻳﺎم‬5-3 ‫ اﻟﻤﺪى اﻟﻘﺼﻴﺮ ﻳﻘﻮل‬‫ﻟﺘﺨﺰﻳﻦ اﻷﻃﻌﻤﺔ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ ﻟﻔﺘﺮة ﻗﺼﻴﺮة ﻋﻠ‬ ‫ ﻣﺜﻞ‬.‫ درﺟﺔ ﻣﺌﻮﻳﺔ‬3 ‫ و‬0 ‫ درﺟﺔ اﻟﺤﺮارة ﺑﻴﻦ‬‫ ‐ اﻟﺘﺨﺰﻳﻦ اﻟﺒﺎرد ﻫﻮ واﺣﺪ ﻳﺘﻢ ﻓﻴﻬﺎ اﻟﺤﻔﺎظ ﻋﻠ‬.‫ﺎ ﺗﺤﺖ اﻟﺘﺨﺰﻳﻦ اﻟﻤﺒﺮد‬‫اﻟﺒﻴﺾ ﻋﻤﻮﻣ‬ ‫ ﺣﺎﻟﺔ اﻟﻔﻮاﻛﻪ‬‫ﻦ أن ﺗﻤﺴﻚ ﺑﻘﺎﻳﺎ اﻟﻄﻌﺎم أﻛﺜﺮ ﻣﻦ أﺳﺒﻮع وﻓ‬‫ ﻫﺬه ﻳﻤ‬.‫ اﻟﻤﺴﺎﺣﺎت أﻳﻀﺎ ﻛﻐﺮف اﻟﺒﺮد‬‫ﻫﺬا اﻟﺘﺨﺰﻳﻦ وﺗﺴﻤ‬ ‫ ﺷﻬﺮ ﺣﺴﺐ اﻟﺘﻨﻮع واﻟﻤﺮﺣﻠﺔ‬‫ ﻣﺎ ﻳﺼﻞ إﻟ‬‫ ﺣﺘ‬، ‫واﻟﺨﻀﺮوات‬ maturity. Fruits and vegetables are usually stored in this type of storage. – Freezer storage is apt for long term storage of perishable foods and the temperature ranges from -20 °C to 0 °C. Pretreatments like blanching, quick cooling to freezing temperature and packing in air tight containers are necessary for successful freezing.. 11 Yanal ALbawarshi ‫ اﻟﻤﺪى اﻟﻄﻮﻳﻞ‬‫ ‐ ﺗﺨﺰﻳﻦ اﻟﻔﺮﻳﺰر ﻣﻨﺎﺳﺐ ﻟﻠﺘﺨﺰﻳﻦ ﻋﻠ‬.‫ ﻫﺬا اﻟﻨﻮع ﻣﻦ اﻟﺘﺨﺰﻳﻦ‬‫ ﻋﺎدة ﻣﺎ ﻳﺘﻢ ﺗﺨﺰﻳﻦ اﻟﻔﻮاﻛﻪ واﻟﺨﻀﺮوات ﻓ‬.‫ﻧﻀﺞ‬ ‫ ﻣﻌﺎﻟﺠﺎت ﻣﺜﻞ اﻟﺘﺨﻠﺺ ﻣﻦ اﻟﺘﺒﺮﻳﺪ اﻟﺴﺮﻳﻊ‬.‫ درﺟﺔ ﻣﺌﻮﻳﺔ‬0 ‫ درﺟﺔ ﻣﺌﻮﻳﺔ إﻟ‬20‐ ‫ﻟﻸﻃﻌﻤﺔ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ ودرﺟﺔ اﻟﺤﺮارة ﻳﺘﺮاوح ﻣﻦ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬11.. ‫ ﺣﺎوﻳﺎت اﻟﻬﻮاء ﺿﺮورﻳﺔ اﻟﺘﺠﻤﻴﺪ اﻟﻨﺎﺟﺢ‬‫ﻣﻦ اﻟﻀﺮوري ﻟﺪرﺟﺔ أن درﺟﺔ اﻟﺤﺮارة واﻟﺘﻌﺒﺌﺔ ﻓ‬ Page (11)  polyphenol oxidases oxidation of phenols in plant tissues to orthoquinones by phenolases, peroxidases and polyphenol oxidases (PPO). Dr. Yanl AlLbawarshi 12  made by Echo https://t.me/mkfrbot Page (12) Essential features of food Storage Areas The proper storage of preprocessed as well as post - processed foods is a key factor in the shelf -life of the food. The essential features of any food storage areas are as follows: It should be fit for purpose (dry store, chill, frozen etc.) i.e. it must provide proper temperatures and humidity for prolonging shelf life of foods ‫ﺎ ﻋﺎﻣﻞ ﻓ‬‫ اﻟﻤﻴﺰات اﻷﺳﺎﺳﻴﺔ ﻟﻤﻨﺎﻃﻖ ﺗﺨﺰﻳﻦ اﻷﻏﺬﻳﺔ ﻳﻌﺪ اﻟﺘﺨﺰﻳﻦ اﻟﻤﻨﺎﺳﺐ ﻟﻸﻃﻌﻤﺔ اﻟﻤﻌﺎﻟﺠﺔ ﻣﺴﺒﻘًﺎ وﻛﺬﻟﻚ ﺑﻌﺪ اﻟﻤﻌﺎﻟﺠﺔ ﻣﻔﺘﺎﺣ‬ ، ‫ﺎ ﻟﻠﻐﺮض )اﻟﻤﺘﺠﺮ اﻟﺠﺎف‬‫ﻮن ﻣﻨﺎﺳﺒ‬‫ ﻳﺠﺐ أن ﻳ‬:‫ اﻟﻤﻴﺰات اﻷﺳﺎﺳﻴﺔ ﻷي ﺗﺨﺰﻳﻦ ﻃﻌﺎم اﻟﻤﻨﺎﻃﻖ ﻛﻤﺎ ﻳﻠ‬.‫اﻟﺠﺮف ‐ﺣﻴﺎة اﻟﻄﻌﺎم‬ ‫ أي ﻳﺠﺐ أن ﻳﻮﻓﺮ درﺟﺎت اﻟﺤﺮارة اﻟﻤﻨﺎﺳﺒﺔ واﻟﺮﻃﻮﺑﺔ ﻹﻃﺎﻟﺔ ﻣﺪة اﻟﺼﻼﺣﻴﺔ ﻟﻸﻃﻌﻤﺔ‬، (‫ ذﻟﻚ‬‫ اﻟﻤﺠﻤﺪ وﻣﺎ إﻟ‬، ‫اﻟﺒﺮد‬ The separate area could be designated for different types of food. For example raw and cooked should be stored separately. It should be able to provide protection from contamination/ infestation It should be weatherproof It should be able to keep out direct sunlight/ heat It should have suitable space and structural arrangement for providing ‫ﻮن‬‫ ﻳﺠﺐ أن ﺗ‬.‫ﻞ ﻣﻨﻔﺼﻞ‬‫ ل ﻳﺠﺐ ﺗﺨﺰﻳﻦ ﻣﺜﺎل اﻟﺨﺎم واﻟﻤﻄﺒﻮخ ﺑﺸ‬.‫ﻦ ﺗﻌﻴﻴﻦ اﻟﻤﻨﻄﻘﺔ اﻟﻤﻨﻔﺼﻠﺔ ﻷﻧﻮاع ﻣﺨﺘﻠﻔﺔ ﻣﻦ اﻟﻄﻌﺎم‬‫ ﻳﻤ‬ /‫ إﺑﻌﺎد أﺷﻌﺔ اﻟﺸﻤﺲ‬‫ا ﻋﻠ‬‫ﻮن ﻗﺎدر‬‫ﻮن ﻣﻘﺎوﻣﺔ ﻟﻠﻄﻘﺲ ﻳﺠﺐ أن ﻳ‬‫ اﻹﺻﺎﺑﺔ ﻳﺠﺐ أن ﺗ‬/‫ ﺗﻮﻓﻴﺮ اﻟﺤﻤﺎﻳﺔ ﻣﻦ اﻟﺘﻠﻮث‬‫ﻗﺎدرة ﻋﻠ‬ ‫ ﻟﺘﻮﻓﻴﺮﻫﺎ‬‫ﻠ‬‫ﻮن ﻟﻬﺎ ﻣﺴﺎﺣﺔ ﻣﻨﺎﺳﺒﺔ وﺗﺮﺗﻴﺐ ﻫﻴ‬‫اﻟﺤﺮارة اﻟﻤﺒﺎﺷﺮة ﻳﺠﺐ أن ﻳ‬ sufficient light and ventilation. It should be easily cleanable. It should provide easy access to materials It should be accessible for transport of food 12 Yanal ALbawarshi ‫ﻮن‬‫ اﻟﻤﻮاد ﻳﺠﺐ أن ﻳ‬‫ ﻳﺠﺐ أن ﻳﻮﻓﺮ ﺳﻬﻮﻟﺔ اﻟﻮﺻﻮل إﻟ‬.‫ﻮن ﻗﺎﺑﻠﺔ ﻟﻠﺘﻨﻈﻴﻒ ﺑﺴﻬﻮﻟﺔ‬‫ ﻳﺠﺐ أن ﺗ‬.‫ واﻟﺘﻬﻮﻳﺔ‬‫ﺎﻓ‬‫اﻟﻀﻮء اﻟ‬ ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬12 ‫ﺎ ﻟﻨﻘﻞ اﻟﻄﻌﺎم‬‫ﻣﺘﺎﺣ‬ Page (12)  Prevention of browning 1- Eliminating oxygen (storing in an inert atmosphere or vacuum) 2- Lowering enzyme enzyme activity a- The optimum pH for phenoloxidase is 7, and so citric or malic acid can be added to retard browning b- Briefly heat to deactivate enzyme (blanching) 3- Add reducing agents (ascorbic acid, sulfites) Oxidation occurs The apple is protected when when the apple is left dipped in orange juice containing exposed to air the antioxidant vitamin C Dr. Yanl AlLbawarshi 13  made by Echo https://t.me/mkfrbot Page (13) Table 1 : Storage life of some foods Food product Storage life (days) at 21 oC Raw beef and mutton 1 -2 Raw fish 1 -2 Raw poultry 1 -2 Dried salted or smoked 2‐ 1 ‫ درﺟﺔ ﻣﺌﻮﻳﺔ ﻟﺤﻢ اﻟﺒﻘﺮ اﻟﺨﺎم وﻟﺤﻢ اﻟﻀﺄن‬21 ‫ ﻋﻤﺮ ﺗﺨﺰﻳﻦ ﺑﻌﺾ اﻷﻃﻌﻤﺔ ﻋﻤﺮ ﺗﺨﺰﻳﻦ اﻟﻤﻨﺘﺠﺎت اﻟﻐﺬاﺋﻴﺔ )أﻳﺎم( ﻓ‬:1 ‫اﻟﺠﺪول‬ ‫ ﻣﺠﻔﻒ ﻣﻤﻠﺢ أو ﻣﺪﺧﻦ‬2‐ 1 ‫ اﻟﺪواﺟﻦ اﻟﺨﺎم‬2‐ 1 ‫اﻷﺳﻤﺎك اﻟﺨﺎم‬ meat and fish 360 or more Fresh fruits 1 -7 Dried fruits 360 or more Leafy vegetables 1 -2 Root crops 1 -20 1 ‫ ﻣﺤﺎﺻﻴﻞ اﻟﺠﺬر‬2‐ 1 ‫ أو أﻛﺜﺮ اﻟﺨﻀﺮوات اﻟﻮرﻗﻴﺔ‬360 ‫ اﻟﻔﻮاﻛﻪ اﻟﻤﺠﻔﻔﺔ‬7‐ 1 ‫ أو أﻛﺜﺮ اﻟﻔﻮاﻛﻪ اﻟﻄﺎزﺟﺔ‬360 ‫اﻟﻠﺤﻮم واﻷﺳﻤﺎك‬ 20‐ Dried seeds 360 or more 13 Yanal ALbawarshi ‫ أو أﻛﺜﺮ‬360 ‫اﻟﺒﺬور اﻟﻤﺠﻔﻔﺔ‬ Page (13)  Oxidoreductases: 1- PEROXIDASE (POD) Iron-containing enzyme. Has a heme prosthetic group N N Thermo-resistant – denaturation at ~ 85 C o Fe N N Since is thermoresistant - indicator of proper blanching (no POD activity in properly blanched vegetables) 2- Catalase When coupled with glucose oxidase the net result is uptake of ½ O2 per molecule of glucose Dr. Yanl AlLbawarshi 14  made by Echo https://t.me/mkfrbot Page (14) Definition of Food Preservation Food preservation can be defined as the science that deals with the process of prevention of decay or spoilage of food thus, allowing it to be stored in a fit condition for future use. Microorganisms are responsible for causing or accelerating spoilage but also in some cases, use of benign bacteria ‫ أﻧﻪ اﻟﻌﻠﻢ اﻟﺬي ﻳﺘﻌﺎﻣﻞ ﻣﻌﻪ ﻋﻤﻠﻴﺔ اﻟﻮﻗﺎﻳﺔ ﻣﻦ اﻻﻧﺤﻼل أو ﺗﻠﻒ‬‫ اﻟﻄﻌﺎم ﻋﻠ‬‫ﻦ ﺗﻌﺮﻳﻒ اﻟﺤﻔﺎظ ﻋﻠ‬‫ اﻟﻄﻌﺎم ﻳﻤ‬‫ ﺗﻌﺮﻳﻒ اﻟﺤﻔﺎظ ﻋﻠ‬ ‫ اﻟﻤﺴﺆوﻟﺔ ﻋﻦ اﻟﺘﺴﺒﺐ أو‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻫ‬‫ اﻟ‬.‫ اﻟﻤﺴﺘﻘﺒﻞ‬‫ ﺣﺎﻟﺔ ﻣﻼﺋﻤﺔ ﻟﻼﺳﺘﺨﺪام ﻓ‬‫ اﻟﺴﻤﺎح ﺑﺘﺨﺰﻳﻨﻬﺎ ﻓ‬، ‫ﺬا‬‫اﻟﻐﺬاء ﻫ‬ ‫ﺘﻴﺮﻳﺎ اﻟﺤﻤﻴﺪة‬‫ اﺳﺘﺨﺪام اﻟﺒ‬، ‫ ﺑﻌﺾ اﻟﺤﺎﻻت‬‫ﺎ ﻓ‬‫ﻦ أﻳﻀ‬‫اﻟﺘﺴﺎرع ﺗﻠﻒ وﻟ‬ and yeasts add specific qualities and preserve food e.g. cheese, wine. Spoilage results in loss of quality, edibility or nutritive value of food. Preservation usually involves the process of treating and handling food to stop or greatly slow down spoilage as well as maintaining or creating nutritional value, texture and flavor of ‫ ﻓﻘﺪان اﻟﺠﻮدة أو ﻗﺎﺑﻠﻴﺔ‬‫ ﻳﺆدي اﻟﺘﻠﻒ إﻟ‬.‫ ﺧﻤﺮ‬، ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل اﻟﺠﺒﻦ‬‫ اﻟﻄﻌﺎم ﻋﻠ‬‫وﺗﻀﻴﻒ اﻟﺨﻤﻴﺮة ﺻﻔﺎت ﻣﺤﺪدة واﻟﺤﻔﺎظ ﻋﻠ‬ ‫ﻞ ﻛﺒﻴﺮ‬‫ ﻋﻤﻠﻴﺔ ﻋﻼج و اﻟﺘﻌﺎﻣﻞ ﻣﻊ اﻟﻄﻌﺎم ﻟﻠﺘﻮﻗﻒ أو اﻟﺘﺒﺎﻃﺆ ﺑﺸ‬‫ ﻋﺎدة ﻣﺎ ﻳﻨﻄﻮي اﻟﺤﻔﺎظ ﻋﻠ‬.‫اﻻﺳﺘﺨﺪام أو اﻟﻘﻴﻤﺔ اﻟﻐﺬاﺋﻴﺔ ﻟـ ﻃﻌﺎم‬ ‫ﻬﺔ‬‫ أو ﺧﻠﻖ ﻗﻴﻤﺔ ﻏﺬاﺋﻴﺔ وﻣﻠﻤﺲ وﻧ‬‫اﻟﺤﻔﺎظ ﻋﻠ‬ food. 14 Yanal ALbawarshi Yalhawa ‫ اﻟﺘﺤﺮﻳﺮ واﻟﺴﺮد‬14.‫ﻃﻌﺎم‬ Page (14) Oxidoreductases: 3- Lipoxygenase Catalyzes peroxidation of fatty acids, Oxidation of lipids with cis, cis groups into conjugated cis, trans hydroperoxides.. Abstracts an H , allows reaction with O2, free radicals produced - Leads to rancidity and flavor - Co-oxidations - Bleaching flour - Thiols - Vitamins Dr. Yanl AlLbawarshi 15  made by Echo https://t.me/mkfrbot Page (15) Importance of Food Preservation Food preservation activities are as old as human race. It had an important role in the spread of civilization. Delay in the consumption or processing of fresh foods alters its freshness, color , texture, palatability and nutritive value, organoleptic desirability, aesthetic appeal and safety..‫ اﻧﺘﺸﺎر اﻟﺤﻀﺎرة‬‫ ﻛﺎن ﻟﺪﻳﻪ دور ﻣﻬﻢ ﻓ‬.‫ اﻷﻏﺬﻳﺔ ﻗﺪﻳﻤﺔ ﻗﺪم اﻟﺠﻨﺲ اﻟﺒﺸﺮي‬‫ اﻟﻄﻌﺎم أﻧﺸﻄﺔ اﻟﺤﻔﺎظ ﻋﻠ‬‫ أﻫﻤﻴﺔ اﻟﺤﻔﺎظ ﻋﻠ‬ ‫ اﻟﺤﺴﻢ اﻟﻌﻀﻮي اﻟﺮﻏﺒﺔ‬، ‫ اﻟﻠﻮن واﻟﻤﻠﻤﺲ واﻟﺴﻌﺔ واﻟﻘﻴﻤﺔ اﻟﻐﺬاﺋﻴﺔ‬، ‫ ﻳﻐﻴﺮ اﺳﺘﻬﻼك أو ﻣﻌﺎﻟﺠﺔ اﻷﻃﻌﻤﺔ اﻟﻄﺎزﺟﺔ ﻧﻀﺎرة‬‫ﺗﺄﺧﻴﺮ ﻓ‬.‫واﻟﺠﺎذﺑﻴﺔ اﻟﺠﻤﺎﻟﻴﺔ واﻟﺴﻼﻣﺔ‬ 15 Yanal ALbawarshi ‫ ﺟﺎﻧﺎل أﻟﺒﺎرﺷ‬15 Page (15) Amylase a-amylase (endo-splitting) glucoamylase Starch Dextrins Glucose Highly viscous Glucose suspension of isomerase polymerized corn starch Fructose 105°C Dr. Yanl AlLbawarshi 16  made by Echo https://t.me/mkfrbot Page (16) Need for Food Preservation Eat what you can and CAN what you can ’t. Preservation of fresh produce is needed for following reasons: - For increasing availability of certain foods which have a short growing season such as fruits and vegetables, for use throughout the year. - For utilization of surplus crops and prevent wastage. :‫ اﻟﻤﻨﺘﺠﺎت اﻟﻄﺎزﺟﺔ ﻷﺳﺒﺎب اﻟﺘﺎﻟﻴﺔ‬‫ اﻟﺤﻔﺎظ ﻋﻠ‬‫ ﻫﻨﺎك ﺣﺎﺟﺔ إﻟ‬.‫ﻨﻚ‬‫ اﻟﻄﻌﺎم أﻛﻞ ﻣﺎ ﺗﺴﺘﻄﻴﻊ وﻣﺎ ﻳﻤ‬‫ اﻟﺤﻔﺎظ ﻋﻠ‬‫ اﻟﺤﺎﺟﺔ إﻟ‬ ‫ ‐ ﻻﺳﺘﺨﺪام ﻓﺎﺋﺾ‬.‫ ﻣﺪار اﻟﻌﺎم‬‫ ﻟﻼﺳﺘﺨﺪام ﻋﻠ‬، ‫ ﻟﻬﺎ ﻣﻮﺳﻢ ﻧﻤﻮ ﻗﺼﻴﺮ ﻣﺜﻞ ﻛﻔﻮاﻛﻪ واﻟﺨﻀﺮوات‬‫‐ ﻟﺰﻳﺎدة ﺗﻮاﻓﺮ ﺑﻌﺾ اﻷﻃﻌﻤﺔ اﻟﺘ‬.‫اﻟﻤﺤﺎﺻﻴﻞ وﻣﻨﻊ اﻟﻬﺪر‬ - For saving money by preserving foods when they are most plentiful, cheaper and are of good quality. - For producing food which is easier to store, distribute and transport and that can be made available in all places at all times. - For meeting the needs of the people for food in secluded and difficult areas. - For ensuring supply of protective foods in homes, hotels and other such places. ‫ ‐ ﻹﻧﺘﺎج اﻟﻄﻌﺎم اﻟﺬي ﻳﺴﻬﻞ‬.‫ﻮن أﻛﺜﺮ وﻓﺮة وأرﺧﺺ و ذات ﻧﻮﻋﻴﺔ ﺟﻴﺪة‬‫ اﻷﻃﻌﻤﺔ ﻋﻨﺪﻣﺎ ﺗ‬‫‐ ﻟﺘﻮﻓﻴﺮ اﻟﻤﺎل ﻣﻦ ﺧﻼل اﻟﺤﻔﺎظ ﻋﻠ‬ ‫ ‐ ﻟﺘﻠﺒﻴﺔ اﺣﺘﻴﺎﺟﺎت اﻟﻨﺎس ﻣﻦ أﺟﻞ اﻟﻄﻌﺎم ﻓ‬.‫ ﺟﻤﻴﻊ اﻷوﻗﺎت‬‫ ﺟﻤﻴﻊ اﻷﻣﺎﻛﻦ ﻓ‬‫ﻨﻪ إﺗﺎﺣﺔ ﻓ‬‫ﺗﺨﺰﻳﻨﻪ وﺗﻮزﻳﻌﻪ وﻧﻘﻠﻪ واﻟﺬي ﻳﻤ‬.‫ اﻟﻤﻨﺎزل واﻟﻔﻨﺎدق وﻏﻴﺮﻫﺎ ﻣﻦ اﻷﻣﺎﻛﻦ‬‫ ‐ ﻟﻀﻤﺎن ﺗﻮﻓﻴﺮ اﻷﻃﻌﻤﺔ اﻟﻮاﻗﻴﺔ ﻓ‬.‫ﻣﻨﺎﻃﻖ ﻣﻨﻌﺰﻟﺔ وﺻﻌﺒﺔ‬ 16 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬16 Page (16)  Factors Affecting Enzymatic Activity Factors responsible for controlling enzymatic activities are 1- temperature, 2- water activity, 3- pH and 4- chemicals which can inhibit or enhance enzyme activity. Enzymes can act between 0°C and 60°C but 37°C is optimum temperature. Enzymes can be permanently inactivated by heat. It has been seen that for each 10°C rise in temperature, the activity of microorganisms and enzymes increases by at least twice, in the range 0- 60°C. Above this, heat quickly destroys enzymes and stops living cells from working. (Q10) All enzymes are inactivated at 80°C. Decreased temperatures therefore work by slowing down these changes. Dr. Yanl AlLbawarshi 17  made by Echo https://t.me/mkfrbot Page (17) It also includes process preservation mainly prevents the growth of bacteria, fungi, and other microorganisms. the oxidation of fats which causes " Rancidification"rancidity and to inhibit natural ageing and discolouration due to enzymatic browning. In some cases, preservation also includes sealing of food materials after ‫ أﻛﺴﺪة‬.‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ اﻷﺧﺮى‬‫ﺘﻴﺮﻳﺎ واﻟﻔﻄﺮﻳﺎت واﻟ‬‫ ﻳﻤﻨﻊ اﻟﻨﻤﻮ ﻣﻦ اﻟﺒ‬‫ﻞ أﺳﺎﺳ‬‫ اﻟﻌﻤﻠﻴﺔ ﺑﺸ‬‫ﺎ اﻟﺤﻔﺎظ ﻋﻠ‬‫ ﻳﺸﻤﻞ أﻳﻀ‬ ‫ﺎ ﺧﺘﻢ‬‫ ﻳﺸﻤﻞ اﻟﺤﻔﻆ أﻳﻀ‬، ‫ ﺑﻌﺾ اﻟﺤﺎﻻت‬‫ ﻓ‬.‫ ﺗﺘﺴﺒﺐ وﻣﻨﻊ اﻟﺸﻴﺨﻮﺧﺔ اﻟﻄﺒﻴﻌﻴﺔ وﺗﻐﻴﺮ ﻟﻮﻧﻬﺎ ﺑﺴﺒﺐ اﻷﻧﺰﻳﻤﻴﺔ ﺑﺮاوﻧﻨﺞ‬‫اﻟﺪﻫﻮن اﻟﺘ‬ ‫اﻟﻤﻮاد اﻟﻐﺬاﺋﻴﺔ ﺑﻌﺪ‬ heat treatment to avoid recontamination with microbes, such as canning. Methods like drying, allow food to be stored without any special control for long periods. A number of preservation methods include drying, spray drying, freeze drying, freezing, vacuum -packing, canning, food irradiation, and adding ‫ اﺳﻤﺢ ﻟﺘﺨﺰﻳﻦ اﻟﻄﻌﺎم دون أي‬، ‫ ﻃﺮق ﻣﺜﻞ اﻟﺘﺠﻔﻴﻒ‬.‫ ﻣﺜﻞ ﻣﺜﻞ اﻟﺘﻌﻠﻴﺐ‬، ‫ﺮوﺑﺎت‬‫اﻟﻤﻌﺎﻟﺠﺔ اﻟﺤﺮارﻳﺔ ﻟﺘﺠﻨﺐ إﻋﺎدة اﻟﺘﻠﻮث ﻣﻊ اﻟﻤﻴ‬ ، ‫ ﺗﻌﺒﺌﺔ اﻟﻔﺮاغ‬، ‫ اﻟﺘﺠﻤﻴﺪ‬، ‫ اﻟﺘﺠﻤﻴﺪ اﻟﺘﺠﻔﻴﻒ‬، ‫ ﺗﺠﻔﻴﻒ اﻟﺮش‬، ‫ ﻳﺸﻤﻞ ﻋﺪد ﻣﻦ ﻃﺮق اﻟﺤﻔﻆ اﻟﺘﺠﻔﻴﻒ‬.‫ﺳﻴﻄﺮة ﺧﺎﺻﺔ ﻟﻔﺘﺮات ﻃﻮﻳﻠﺔ‬ ‫ وإﺿﺎﻓﺔ‬، ‫ ﺗﺸﻌﻴﻊ اﻟﻄﻌﺎم‬، ‫ﺗﻌﻠﻴﺐ‬ preservatives or inert "Gas “ gases such as carbon dioxide. Other methods that not only help to preserve food, but also add flavor, include pickling, salting, smoking, preserving in sugar syrup and curing. 17 Yanal ALbawarshi ‫ﺎ‬‫ﻦ أﻳﻀ‬‫ وﻟ‬، ‫ اﻟﻄﻌﺎم‬‫ اﻟﺤﻔﺎظ ﻋﻠ‬‫ ﻻ ﺗﺴﺎﻋﺪ ﻓﻘﻂ ﻓ‬‫ اﻟﻄﺮق اﻟﺘ‬.‫ﺮﺑﻮن‬‫ أﻛﺴﻴﺪ اﻟ‬‫اﻟﻤﻮاد اﻟﺤﺎﻓﻈﺔ أو اﻟﻐﺎزات "اﻟﻐﺎز" اﻟﺨﺎﻣﻠﺔ ﻣﺜﻞ ﺛﺎﻧ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬17.‫ﺮ واﻟﻤﻌﺎﻟﺠﺔ‬‫ ﺷﺮاب اﻟﺴ‬‫ اﻟﺤﻔﺎظ ﻋﻠ‬، ‫ اﻟﺘﺪﺧﻴﻦ‬، ‫ اﻟﺘﻤﻠﻴﺢ‬، ‫ ﺗﺸﻤﻞ اﻟﺘﺨﻠﻴﻞ‬، ‫ﻬﺔ‬‫إﺿﺎﻓﺔ اﻟﻨ‬ Page (17)  Spoilage Due to Insects, Pests and Rodents The main categories of foods subject to insects and pest attack are fruits, vegetables, grains and their processed products. Warm humid environment promote insect growth, although most insects will not breed if the temperature exceeds above 35°C or falls below 10°C. Many insects cannot reproduce satisfactorily unless the moisture content of their food is greater than 11 percent. The presence of insects and pests and their excreta in foods may render consumable loss in the nutritional quality, production of off-flavours and acceleration of decay processes due to creation of higher temperatures and moisture levels and release of enzymes. The products of insect and pests activities such as webbing, clumped-together food particles and holes can also reduce the food values. Rats and mice carry disease-producing microorganisms on their feet and/or in their feces and urine and contaminate the food by their presence. Dr. Yanl AlLbawarshi 18  made by Echo https://t.me/mkfrbot Page (18) Food Spoilage Introduction Healthy tissues inside foods and foods in their natural form resist infection and they do not harbour microorganisms. It is a gradual process occurring because of poor sanitation, enzymatic or chemical reactions, improper temperature controls, microbial growth or ‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ‬‫ ﻣﻘﺎوﻣﺔ اﻟﻌﺪوى وﻫﻢ ﻻ ﻳﺆوي اﻟ‬‫ﻠﻬﺎ اﻟﻄﺒﻴﻌ‬‫ ﺷ‬‫ﺗﻠﻒ اﻟﻐﺬاء ﻣﻘﺪﻣﺔ اﻷﻧﺴﺠﺔ اﻟﺼﺤﻴﺔ داﺧﻞ اﻷﻃﻌﻤﺔ واﻷﻃﻌﻤﺔ ﻓ‬ ‫ اﻟﻀﻮاﺑﻂ ﻏﻴﺮ اﻟﺼﺤﻴﺤﺔ‬، ‫ﻴﻤﻴﺎﺋﻴﺔ‬‫ أو اﻟﺘﻔﺎﻋﻼت اﻟ‬‫ أو اﻷﻧﺰﻳﻤ‬‫ إﻧﻬﺎ ﻋﻤﻠﻴﺔ ﺗﺪرﻳﺠﻴﺔ ﺗﺤﺪث ﺑﺴﺒﺐ ﺿﻌﻒ اﻟﺼﺮف اﻟﺼﺤ‬.‫اﻟﺪﻗﻴﻘﺔ‬ ‫ﺮوﺑﺎت أو‬‫ ﻧﻤﻮ اﻟﻤﻴ‬، ‫ درﺟﺔ اﻟﺤﺮارة‬‫ﻓ‬ physical abuse starting from the time food is harvested, slaughtered or manufactured till it is consumed. Physical changes, such as bruising or puncturing of tissue and water loss and chemical changes, such as those caused by enzymes; or the effects of microbial growth can make food unappealing. ‫ ﻣﺜﻞ‬، ‫ اﻟﺘﻐﻴﻴﺮات اﻟﺠﺴﺪﻳﺔ‬.‫ ﻳﺘﻢ اﺳﺘﻬﻼﻛﻬﺎ‬‫ا ﻣﻦ اﻟﻮﻗﺖ اﻟﺬي ﻳﺘﻢ ﻓﻴﻪ ﺣﺼﺎد اﻟﻄﻌﺎم أو ذﺑﺤﻪ أو ﻣﺼﻨﻌﺔ ﺣﺘ‬‫ ﺑﺪء‬‫اﻹﻳﺬاء اﻟﺒﺪﻧ‬ ‫ﻦ‬‫ﺮوﺑﺎت ﻳﻤ‬‫ ﺗﺴﺒﺒﻬﺎ اﻹﻧﺰﻳﻤﺎت ؛ أو آﺛﺎر ﻧﻤﻮ اﻟﻤﻴ‬‫ ﻣﺜﻞ ﺗﻠﻚ اﻟﺘ‬، ‫ﻴﻤﻴﺎﺋﻴﺔ‬‫ﺪﻣﺎت أو ﺛﻘﺐ اﻷﻧﺴﺠﺔ وﻓﻘﺪان اﻟﻤﺎء و اﻟﺘﻐﻴﺮات اﻟ‬‫اﻟ‬.‫أن ﺗﺠﻌﻞ اﻟﻐﺬاء ﻏﻴﺮ ﺟﺬاب‬ Spoilage of food refers to the undesirable alterations in foods or the food undergoes some physiological, chemical and biological changes, which reduces it inedible or hazardous to eat 18 Yanal ALbawarshi ‫ﻴﻤﻴﺎﺋﻴﺔ‬‫ اﻷﻃﻌﻤﺔ أو اﻟﻄﻌﺎم ﻳﺨﻀﻊ ﻟﺒﻌﺾ اﻟﺘﻐﻴﻴﺮات اﻟﻔﺴﻴﻮﻟﻮﺟﻴﺔ واﻟ‬‫ اﻟﺘﻌﺪﻳﻼت ﻏﻴﺮ اﻟﻤﺮﻏﻮب ﻓﻴﻬﺎ ﻓ‬‫ ﻻ ﻳﺸﻴﺮ ﺗﻠﻒ اﻟﻄﻌﺎم إﻟ‬ ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬18 ‫ ﻳﻘﻠﻞ ﻣﻦ ذﻟﻚ ﻏﻴﺮ ﻗﺎﺑﻞ ﻟﻠﺘﻄﺒﻴﻖ أو ﺧﻄﻴﺮ ﻟﺘﻨﺎول اﻟﻄﻌﺎم‬‫ واﻟﺘ‬، ‫واﻟﺒﻴﻮﻟﻮﺟﻴﺔ‬ Page (18)  Spoilage Due to Chemical Reactions Chemical reactions take place in the presence of atmospheric oxygen and sunlight. Two major chemical changes, which occur during the processing and storage of fruits and vegetables, are: 1- lipid oxidation and 2- non-enzymatic browning which deteriorate sensory quality, color and flavor. 1- Lipid oxidation is influenced by light, oxygen, high temperature and the presence of iron and copper, and water activity. Control of these factors can significantly reduce the extent of lipid oxidation or rancidity in foods. Oxidation of fatty acids to other chemicals like aldehydes, ketones, alcohols and esters also results in off-flavors. Dr. Yanl AlLbawarshi 19  made by Echo https://t.me/mkfrbot Page (19) Major reasons for a food being rejected as spoiled 1. Organoleptic changes brought about by the growth of microorganisms. 2. Chemical changes in a food e.g. oxidative rancidity of fats, browning of fruits and vegetables. 3. Physical changes e.g. burning, drying, pressure, freezer burn etc. ‫ﻴﻤﻴﺎﺋﻴﺔ‬‫ اﻟﺘﻐﻴﺮات اﻟ‬.2.‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ‬‫ اﻟﺘﻐﻴﻴﺮات اﻟﺤﺴﻢ اﻟﻨﺎﺗﺠﺔ ﻋﻦ ﻧﻤﻮ اﻟ‬.1 ‫ أﻧﻪ ﻣﺪﻟﻞ‬‫ أﺳﺒﺎب رﺋﻴﺴﻴﺔ ﻟﺮﻓﺾ اﻟﻄﻌﺎم ﻋﻠ‬ ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل ﺣﺮق‬‫ اﻟﺘﻐﻴﻴﺮات اﻟﻤﺎدﻳﺔ ﻋﻠ‬.3.‫ ﺑﺮاون ﻣﻦ اﻟﻔﻮاﻛﻪ واﻟﺨﻀﺮوات‬، ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل ﻛﺮوﻳﺔ ﻣﺆﻛﺴﺪة ﻟﻠﺪﻫﻮن‬‫ اﻟﻄﻌﺎم ﻋﻠ‬‫ﻓ‬.‫ ذﻟﻚ‬‫ ﺣﺮق اﻟﻔﺮﻳﺰر وﻣﺎ إﻟ‬، ‫ اﻟﻀﻐﻂ‬، ‫ ﺗﺠﻔﻴﻒ‬، 4. Staling due to changes in H 2 O content giving a change in texture e.g. stale baked products. 5. Over Ripening overripe fruits are considered spoiled. 6. Contamination with chemical agents e.g. sanitizers that give rise to unacceptable odors and flavors. 7. Microorganisms and Insects. ‫ ﺗﻌﺘﺒﺮ اﻟﻔﻮاﻛﻪ‬.5.‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل ﻣﻨﺘﺠﺎت ﻣﺨﺒﻮزة ﻗﺪﻳﻤﺔ‬‫ اﻟﻤﻠﻤﺲ ﻋﻠ‬‫ إﻋﻄﺎء ﺗﻐﻴﻴﺮ ﻓ‬H 2 o ‫ ﻣﺤﺘﻮى‬‫ اﻟﺘﺜﺒﻴﺖ ﺑﺴﺒﺐ اﻟﺘﻐﻴﻴﺮات ﻓ‬.4.7.‫ﻬﺎت ﻏﻴﺮ ﻣﻘﺒﻮﻟﺔ‬‫ رواﺋﺢ وﻧ‬‫ ﺗﺆدي إﻟ‬‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل اﻟﻤﻄﻬﺮات اﻟﺘ‬‫ ﻋﻠ‬، ‫ﻴﻤﻴﺎﺋﻴﺔ‬‫ اﻟﺘﻠﻮث ﺑﺎﻟﻌﻮاﻣﻞ اﻟ‬.6.‫ﺔ‬‫اﻟﻨﺎﺿﺠﺔ اﻟﻨﺰﻳﻬﺔ ﻣﺪﻟ‬.‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ واﻟﺤﺸﺮات‬‫اﻟ‬ 19 Yanal ALbawarshi Janal Albawarshi 19 Page (19)  Dehydrated green peas and beans packed in glass containers undergo photo-oxidation and loss of desirable color occurs. Freezer induced damage observed in frozen foods affects its quality. Anthocyanins, the pigment in fresh and processed foods, form complexes with metals resulting in the change in color. E.g. Red sour cherries react with tin and form undesirable purple complex. Carotenoid, another color pigment, degrades by oxidation in the presence oxygen, light and heat. Dr. Yanl AlLbawarshi 20  made by Echo https://t.me/mkfrbot Page (20) Factors Affecting food Spoilage The types of spoilage of a particular food item depend to a great extent on the following: The composition of food: The composition of food influences its susceptibility to spoilage. For example - presence of proteins and carbohydrates especially sugars are preferred by microorganisms for energy source. Very few utilize fat for energy production. ‫ﻮﻳﻦ‬‫ ﻳﺆﺛﺮ ﺗ‬:‫ﻮﻳﻦ اﻟﻄﻌﺎم‬‫ ﺗ‬:‫ ﻣﺎ ﻳﻠ‬‫ ﺣﺪ ﻛﺒﻴﺮ ﻋﻠ‬‫ ﻣﻌﻴﻦ إﻟ‬‫ ﺗﻠﻒ اﻟﻐﺬاء ﺗﻌﺘﻤﺪ أﻧﻮاع ﺗﻠﻒ ﻋﻨﺼﺮ ﻏﺬاﺋ‬‫ ﺗﺆﺛﺮ ﻋﻠ‬‫ اﻟﻌﻮاﻣﻞ اﻟﺘ‬ ‫ﺎﺋﻨﺎت‬‫ﺮﻳﺎت ﻣﻔﻀﻠﺔ ﻣﻦ ﻗﺒﻞ اﻟ‬‫ﺮﺑﻮﻫﻴﺪرات وﺧﺎﺻﺔ اﻟﺴ‬‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل ‐ وﺟﻮد اﻟﺒﺮوﺗﻴﻨﺎت واﻟ‬‫ ﻋﻠ‬.‫ ﻗﺎﺑﻠﻴﺘﻪ ﻟﻠﺘﻠﻒ‬‫اﻟﻄﻌﺎم ﻋﻠ‬.‫ ﻋﺪد ﻗﻠﻴﻞ ﺟﺪا ﻣﻦ اﺳﺘﺨﺪام اﻟﺪﻫﻮن ﻹﻧﺘﺎج اﻟﻄﺎﻗﺔ‬.‫اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻟﻠﻄﺎﻗﺔ ﻣﺼﺪر‬ Structure of the food item: Whole healthy tissues of food from inside are sterile or low in microbial content. Skin, rind or shell on food works as its protective covering from spoilage microorganisms. Types of microorganisms involved: The types of microorganisms present in food depend on its composition of food. Conditions of storage of the food: ‫ ﻗﺸﺮة‬، ‫ اﻟﺠﻠﺪ‬.‫ﺮوﺑ‬‫ اﻟﻤﺤﺘﻮى اﻟﻤﻴ‬‫ﺎﻣﻠﺔ ﻣﻦ اﻟﻐﺬاء ﻣﻦ اﻟﺪاﺧﻞ ﻣﻌﻘﻤﺔ أو ﻣﻨﺨﻔﻀﺔ ﻓ‬‫ اﻷﻧﺴﺠﺔ اﻟﺼﺤﻴﺔ اﻟ‬:‫ﻞ اﻟﻌﻨﺼﺮ اﻟﻐﺬاﺋ‬‫ ﻫﻴ‬ ‫ ﺗﻌﺘﻤﺪ أﻧﻮاع‬:‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ اﻟﻤﻌﻨﻴﺔ‬‫ أﻧﻮاع اﻟ‬.‫ اﻟﺘﻠﻒ‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻓ‬‫ اﻟﻐﺬاء ﺗﻌﻤﻞ ﻛﻐﻄﺎء واﻗﻴﺔ ﻣﻦ اﻟ‬‫أو ﺷﻞ ﻋﻠ‬ :‫ ﻇﺮوف ﺗﺨﺰﻳﻦ اﻟﻄﻌﺎم‬.‫ﻮﻳﻦ اﻟﻄﻌﺎم‬‫ ﺗ‬‫ اﻟﻐﺬاء ﻋﻠ‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ اﻟﻤﻮﺟﻮدة ﻓ‬‫اﻟ‬ Conditions of storage of food affect the growth of microorganisms. Even if the proper storage of food is done, the food loses its freshness and nutritive value if it is stored for too long. 20 Yanal ALbawarshi ‫ واﻟﻄﻌﺎم ﻳﻔﻘﺪ ﻧﻀﺎرﺗﻪ وﻗﻴﻤﺘﻪ‬، ‫ ﻟﻮ ﻛﺎن اﻟﺼﺤﻴﺢ ﻳﺘﻢ ﺗﺨﺰﻳﻦ اﻟﻄﻌﺎم‬‫ ﺣﺘ‬.‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ‬‫ ﻧﻤﻮ اﻟ‬‫ﺗﺆﺛﺮ ﻇﺮوف ﺗﺨﺰﻳﻦ اﻟﻄﻌﺎم ﻋﻠ‬ ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬20.‫ﺎ ﻃﻮﻳﻞ‬‫اﻟﻐﺬاﺋﻴﺔ إذا ﺗﻢ ﺗﺨﺰﻳﻨﻪ أﻳﻀ‬ Page (20) 2- Non-enzymatic browning is one of the major causes of deterioration which takes place during frying, cooking, storage of dried and concentrated foods through Maillard, caramelization and ascorbic acid oxidation. a.Maillard reaction occurs due to reactions between reducing sugars and amino acids in the presence of heat and results in formation of black brown insoluble pigments. b. Caramelization of sugars occurs in presence of high heat and low moisture content in the food. Dr. Yanl AlLbawarshi 21  made by Echo https://t.me/mkfrbot Page (21) Classification of Foods by ease of Spoilage ( Perishability ) Foods are classified into three groups based on ease of their spoilage. 1 - Relatively stable or non -perishable foods: Foods that do not spoil unless handled carefully. E.g. grains, flour, sugar, pulses etc. 2 - Protectable or semi -perishable foods: Foods those remain unspoiled for a fairly long period if properly handled and stored. E.g. potatoes, apples, ‐ 1.‫ أﺳﺎس ﺳﻬﻮﻟﺔ ﺗﻠﻔﻬﺎ‬‫ ﺛﻼث ﻣﺠﻤﻮﻋﺎت ﻋﻠ‬‫ ﺗﺼﻨﻴﻒ اﻷﻃﻌﻤﺔ ﻋﻦ ﻃﺮﻳﻖ ﺳﻬﻮﻟﺔ اﻟﺘﻠﻒ )ﻗﺎﺑﻠﻴﺔ اﻟﺘﻠﻒ( ﻳﺘﻢ ﺗﺼﻨﻴﻒ اﻷﻃﻌﻤﺔ إﻟ‬ ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل اﻟﺤﺒﻮب واﻟﺪﻗﻴﻖ‬‫ ﻋﻠ‬.‫ ﻻ ﺗﻔﺴﺪ إﻻ إذا ﺗﻢ اﻟﺘﻌﺎﻣﻞ ﻣﻌﻬﺎ ﺑﻌﻨﺎﻳﺔ‬‫ اﻷﻃﻌﻤﺔ اﻟﺘ‬:‫ﺎ أو ﻏﻴﺮ ﻗﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ‬‫اﻷﻃﻌﻤﺔ اﻟﻤﺴﺘﻘﺮة ﻧﺴﺒﻴ‬ ‫ ﺗﻈﻞ ﻏﻴﺮ ﻣﻠﻮﺛﺔ ل ﻓﺘﺮة ﻃﻮﻳﻠﺔ إﻟ‬‫ اﻷﻃﻌﻤﺔ اﻟﺘ‬:‫ﻦ ﺣﻤﺎﻳﺘﻬﺎ أو ﺷﺒﻪ ﻗﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ‬‫ ﻳﻤ‬‫ ‐ اﻷﻃﻌﻤﺔ اﻟﺘ‬2 ‫ ذﻟﻚ‬‫ﺮ واﻟﺒﻘﻮل وﻣﺎ إﻟ‬‫واﻟﺴ‬ ، ‫ اﻟﺘﻔﺎح‬، ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل اﻟﺒﻄﺎﻃﺎ‬‫ ﻋﻠ‬.‫ﻞ ﺻﺤﻴﺢ‬‫ﺣﺪ ﻣﺎ إذا ﺗﻢ اﻟﺘﻌﺎﻣﻞ ﻣﻌﻬﺎ وﺗﺨﺰﻳﻨﻬﺎ ﺑﺸ‬ onions etc. 3 - Perishable foods: Foods that spoil readily unless special preservative methods are used. E.g. milk, eggs, meat, fish, poultry, most fruits and vegetables. Perishable foods can be kept at room temperature for only few hours or 1 or 2 days before spoiling. For example - milk and milk products, meat, fish, ‫ ﻋﻠ‬.‫ﻦ ﺣﺎﻓﻈﺔ ﺧﺎﺻﺔ ﻳﺘﻢ اﺳﺘﺨﺪام اﻟﻄﺮق‬‫ ﺗﻔﺴﺪ ﺑﺴﻬﻮﻟﺔ ﻣﺎ ﻟﻢ ﻳ‬‫ اﻷﻃﻌﻤﺔ اﻟﺘ‬:‫ ‐ اﻷﻃﻌﻤﺔ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ‬3 ‫ ذﻟﻚ‬‫اﻟﺒﺼﻞ وﻣﺎ إﻟ‬ ‫ﻦ اﻻﺣﺘﻔﺎظ ﺑﺎﻷﻃﻌﻤﺔ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ ﻓ‬‫ ﻳﻤ‬.‫ﺳﺒﻴﻞ اﻟﻤﺜﺎل اﻟﺤﻠﻴﺐ واﻟﺒﻴﺾ واﻟﻠﺤﻮم واﻷﺳﻤﺎك واﻟﺪواﺟﻦ وﻣﻌﻈﻢ اﻟﻔﻮاﻛﻪ و اﻟﺨﻀﺎر‬ ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل ‐ ﻣﻨﺘﺠﺎت اﻟﺤﻠﻴﺐ واﻟﺤﻠﻴﺐ واﻟﻠﺤﻮم‬‫ ﻋﻠ‬.‫ ﻗﺒﻞ أﻳﺎم ﻣﻦ اﻹﻓﺴﺎد‬2 ‫ أو‬1 ‫درﺟﺔ ﺣﺮارة اﻟﻐﺮﻓﺔ ﻟﺒﻀﻊ ﺳﺎﻋﺎت أو‬ ، ‫واﻷﺳﻤﺎك‬ poultry, fruits, leafy vegetables and cooked food. 21 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬21.‫اﻟﺪواﺟﻦ واﻟﻔﻮاﻛﻪ واﻟﺨﻀﺮوات اﻟﻮرﻗﻴﺔ واﻟﻄﻌﺎم اﻟﻤﻄﺒﻮخ‬ Page (21)  Spoilage Due to Physical Factors Physical factors such as temperature, moisture and pressure can also cause food spoilage. Physico-chemical reactions are caused by freezing burning, drying and bruising of fruits and vegetables during storage, handling and transportation, which result in food deteriorations. Food processing or storage causes some deterioration in color of fruits and vegetables due to the degradation of the chlorophyll resulting dull olive- brown color. Dr. Yanl AlLbawarshi 22  made by Echo https://t.me/mkfrbot Page (22) 1 - Non - perishable foods will keep for months or years without spoiling unless handled and stored carelessly. Examples of such foods are all preserved food products (canned, dried, pickled etc.), whole cereal, pulse and millet grains, oil seeds, nuts, fats and oils, honey, sugar, jaggery , salt, some spices and essence. 2 - Semi -perishable foods can be stored for a couple of weeks or ‫ أﻣﺜﻠﺔ‬.‫ ‐ اﻷﻃﻌﻤﺔ ﻏﻴﺮ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ ﺳﺘﺤﺘﻔﻆ ﺑﻬﺎ ﻟﻌﺪة أﺷﻬﺮ أو ﺳﻨﻮات ﺑﺪوﻧﻬﺎ إﻓﺴﺎد ﻣﺎ ﻟﻢ ﻳﺘﻢ اﻟﺘﻌﺎﻣﻞ ﻣﻌﻬﺎ وﺗﺨﺰﻳﻨﻬﺎ ﺑﻼ ﻣﺒﺎﻻة‬1 ‫ﺎﻣﻠﺔ واﻟﻨﺒﻀﺎت‬‫ اﻟﺤﺒﻮب اﻟ‬، (‫ ذﻟﻚ‬‫ اﻟﻤﺨﻠﻠﺔ وﻣﺎ إﻟ‬، ‫ اﻟﻤﺠﻔﻔﺔ‬، ‫ ﻫﺬا اﻷﻃﻌﻤﺔ ﺟﻤﻴﻊ اﻟﻤﻨﺘﺠﺎت اﻟﻐﺬاﺋﻴﺔ اﻟﻤﺤﻔﻮﻇﺔ )اﻟﻤﻌﻠﺒﺔ‬‫ﻋﻠ‬ ‐ 2.‫ ﺑﻌﺾ اﻟﺘﻮاﺑﻞ واﻟﺠﻮﻫﺮ‬، ‫ اﻟﻤﻠﺢ‬، jaggery ، ‫ﺮ‬‫ اﻟﺴ‬، ‫ اﻟﻌﺴﻞ‬، ‫ﺴﺮات واﻟﺪﻫﻮن واﻟﺰﻳﻮت‬‫وﺣﺒﻮب اﻟﺪﺧﻦ وﺑﺬور اﻟﺰﻳﺖ واﻟﻤ‬ ‫ﻦ ﺗﺨﺰﻳﻦ اﻷﻃﻌﻤﺔ ﺷﺒﻪ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ ﻟﺒﻀﻌﺔ أﺳﺎﺑﻴﻊ أو‬‫ﻳﻤ‬ even a month or two without any detectable signs of spoilage. Temperature and humidity of the environment again affects the shelf stability of such foods. Proper handling and storage can result in fairly long storage without spoilage. Examples are all cereal and pulse products like wheat flour, semolina, vermicelli, broken wheat, and some fruits and vegetables like citrus fruits, apples, ‫ اﺳﺘﻘﺮار اﻟﺮف‬‫ ﺗﺆﺛﺮ درﺟﺔ ﺣﺮارة ورﻃﻮﺑﺔ اﻟﺒﻴﺌﺔ ﻣﺮة أﺧﺮى ﻋﻠ‬.‫ اﻟﺘﻠﻒ‬‫ﻦ اﻛﺘﺸﺎﻓﻬﺎ ﻋﻠ‬‫ ﺷﻬﺮ أو ﺷﻬﺮﻳﻦ دون أي ﻋﻼﻣﺎت ﻳﻤ‬‫ﺣﺘ‬ ‫ أﻣﺜﻠﺔ ﺟﻤﻴﻊ اﻟﺤﺒﻮب و‬.‫ ﺣﺪ ﻣﺎ دون ﺗﻠﻒ‬‫ اﻟﺘﺨﺰﻳﻦ اﻟﻄﻮﻳﻞ إﻟ‬‫ﻦ أن ﻳﻨﺘﺞ ﻋﻦ اﻟﻤﻨﺎوﻟﺔ واﻟﺘﺨﺰﻳﻦ اﻟﺴﻠﻴﻤﻴﻦ ﻓ‬‫ ﻳﻤ‬.‫ﻣﻦ ﻫﺬه اﻷﻃﻌﻤﺔ‬ ، ‫ وﺑﻌﺾ اﻟﻔﻮاﻛﻪ واﻟﺨﻀﺮوات ﻣﺜﻞ ﺛﻤﺎر اﻟﺤﻤﻀﻴﺎت‬، ‫ﺴﻮرة اﻟﻘﻤﺢ‬‫ ﻣ‬، ‫ ﻓﻴﺮﻣﻴﺴﻴﻠ‬، ‫ ﺳﻤﻴﺪ‬، ‫ﻣﻨﺘﺠﺎت اﻟﻨﺒﺾ ﻣﺜﻞ دﻗﻴﻖ اﻟﻘﻤﺢ‬ ، ‫واﻟﺘﻔﺎح‬ roots and tubers, potatoes, onions, garlic etc. 22 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺒﺎرﺷ‬22 ‫ ذﻟﻚ‬‫اﻟﺠﺬور واﻟﺪرﻧﺎت واﻟﺒﻄﺎﻃﺎ واﻟﺒﺼﻞ واﻟﺜﻮم وﻣﺎ إﻟ‬ Page (22)  Physiological disorders Physiological disorders that occur in fruits and vegetables are chilling injury, freezing injury, heat injury, disorders due to pre-harvest nutrient imbalances, breakdown of fruits and vegetables due to very low (< 1%) oxygen and elevated (> 20%) carbon dioxide concentrations. Freezing injury occurs when fruits and vegetables are held below the freezing temperatures of cell sap, they get damaged, which is referred as freezing injury. Chilling injury occurs when fruits and vegetables are held at temperatures above their freezing point and below 15C depending on the commodity. Chilling injury is more common in fruits which are of tropical or sub-tropical in origin. These include mango, papaya, banana, citrus, tomato, pineapple, guava, cucumber, eggplant and pepper. Chilling injury is manifested in a variety of symptoms, which include surface and internal discoloration (internal/external), surface pitting, appearance of water-soaked areas, necrotic (black spots) areas, uneven ripening or failure to ripen, and off-flavour development. Heat injury results from exposure to direct sunlight or to excessively high temperatures. Symptoms include surface scalding, uneven ripening and excessive softening and desiccation. Dr. Yanl AlLbawarshi 23  made by Echo https://t.me/mkfrbot Page (23) 3 - Perishable foods can be kept at room temperature for only few hours or 1 or 2 days before spoiling. For example - milk and milk products, meat, fish, poultry, fruits, leafy vegetables and cooked food.. The rate of spoilage varies with the temperature, moisture and or dryness of the environment. 23 Yanal ALbawarshi ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل‬‫ ﻋﻠ‬.‫ أو ﻳﻮﻣﻴﻦ ﻗﺒﻞ اﻹﻓﺴﺎد‬1 ‫ درﺟﺔ ﺣﺮارة اﻟﻐﺮﻓﺔ ﻓﻘﻂ ﺑﻀﻊ ﺳﺎﻋﺎت أو‬‫ﻦ اﻻﺣﺘﻔﺎظ ﺑﺎﻷﻃﻌﻤﺔ اﻟﻘﺎﺑﻠﺔ ﻟﻠﺘﻠﻒ ﻓ‬‫ ‐ ﻳﻤ‬3 ‫ ﻳﺨﺘﻠﻒ ﻣﻌﺪل اﻟﺘﻠﻒ‬.. ‫‐ اﻟﺤﻠﻴﺐ وﻣﻨﺘﺠﺎت اﻷﻟﺒﺎن واﻟﻠﺤﻮم واﻷﺳﻤﺎك واﻟﺪواﺟﻦ واﻟﻔﻮاﻛﻪ واﻟﺨﻀﺮوات اﻟﻮرﻗﻴﺔ واﻟﻄﻌﺎم اﻟﻤﻄﺒﻮخ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬23.‫ ﺟﻔﺎف اﻟﺒﻴﺌﺔ‬/ ‫ﻣﻊ درﺟﺔ اﻟﺤﺮارة واﻟﺮﻃﻮﺑﺔ و‬ Page (23)  Effects of Spoilage on Nutritional Quality Effect of spoilage on nutrient degradation cannot be generalized because of the diverse nature of the various nutrients as well as the chemical heterogeneity within each class of compounds and the complex interactions of the above variables. The major nutritional changes which occur in foods due to microbiological, enzymatic and chemical reactions are listed in below Table. Dr. Yanl AlLbawarshi 24  made by Echo https://t.me/mkfrbot Page (24) Causes of Food Spoilage There are mainly three types of causes of food spoilage 1 - Biological causes comprise of growth and activity of microorganisms such as bacteria, yeast and moulds; activity of food enzymes and damage due to pests, insects and rodents etc. ‫ﺎﺋﻨﺎت‬‫ﻮن ﻣﻦ ﻧﻤﻮ وﻧﺸﺎط اﻟ‬‫ ‐ اﻷﺳﺒﺎب اﻟﺒﻴﻮﻟﻮﺟﻴﺔ ﺗﺘ‬1 ‫ﺎ ﺛﻼﺛﺔ أﻧﻮاع ﻣﻦ أﺳﺒﺎب ﺗﻠﻒ اﻟﻐﺬاء‬‫ أﺳﺒﺎب ﺗﻠﻒ اﻟﻐﺬاء ﻫﻨﺎك أﺳﺎﺳ‬ ‫ﺘﻴﺮﻳﺎ واﻟﺨﻤﻴﺮة واﻟﻌﻔﻦ ؛ ﻧﺸﺎط ﻣﻦ إﻧﺰﻳﻤﺎت اﻟﻐﺬاء واﻷﺿﺮار ﺑﺴﺒﺐ اﻵﻓﺎت واﻟﺤﺸﺮات و اﻟﻘﻮارض وﻣﺎ إﻟ‬‫اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻣﺜﻞ اﻟﺒ‬ ‫ذﻟﻚ‬ 2 -Chemical causes include reaction with oxygen and light and chemical reactions within food constituents. 3 -Physical causes consist of temperature and physical abuse , changes caused by freezing, burning, drying, pressure, etc.. 24 Yanal ALbawarshi ‫ أﺳﺒﺎب ﻃﺒﻴﻌﻴﺔ‬3.‫ﻮﻧﺎت اﻟﻐﺬاﺋﻴﺔ‬‫ﻴﻤﻴﺎﺋﻴﺔ داﺧﻞ اﻟﻤ‬‫ﻴﻤﻴﺎﺋﻴﺔ اﻟﺘﻔﺎﻋﻞ ﻣﻊ اﻷﻛﺴﺠﻴﻦ واﻟﻀﻮء و اﻟﺘﻔﺎﻋﻼت اﻟ‬‫ ‐ﺗﺸﻤﻞ اﻷﺳﺒﺎب اﻟ‬2 ‫ ﻳﺎﻧﺎل‬24.‫ ذﻟﻚ‬‫ وﻣﺎ إﻟ‬، ‫ اﻟﻀﻐﻂ‬، ‫ اﻟﺘﺠﻔﻴﻒ‬، ‫ اﻟﺤﺮق‬، ‫ اﻟﺘﻐﻴﻴﺮات اﻟﻨﺎﺟﻤﺔ ﻋﻦ اﻟﺘﺠﻤﺪ‬، ‫ﻮن ﻣﻦ درﺟﺔ اﻟﺤﺮارة واﻻﻋﺘﺪاء اﻟﺒﺪﻧ‬‫ﺗﺘ‬ ‫أﻟﺰارﺷ‬ Page (24)  Shelf life The stated shelf life of a food is the period of time for which it remains safe and suitable for consumption, this means that the food: 1- must remain safe to consume, i.e. should not cause food-poisoning 2- has not deteriorated in quality or spoiled in any way that the consumer would find unacceptable; 3- has not lost significant amounts of any nutrients listed on the label. Yanal ALbawarshi 25  made by Echo https://t.me/mkfrbot Page (25) All of these factors can act together. For example, bacteria, insects, and light, all can be operating concurrently to spoil food in a field or in a warehouse. Similarly, heat, moisture, and air at the same time affect the multiplication and activities of bacteria and chemical activities of food enzymes. ‫ﻞ ﻣﺘﺰاﻣﻦ‬‫ﻦ أن ﺗﻌﻤﻞ ﺟﻤﻴﻌﻬﺎ ﺑﺸ‬‫ ﻳﻤ‬، ‫ اﻟﺤﺸﺮات واﻟﻀﻮء‬، ‫ﺘﻴﺮﻳﺎ‬‫ اﻟﺒ‬، ‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل‬‫ ﻋﻠ‬.‫ﺎ‬‫ﻦ أن ﺗﻌﻤﻞ ﻣﻌ‬‫ ﻛﻞ ﻫﺬه اﻟﻌﻮاﻣﻞ ﻳﻤ‬ ‫ﺘﻴﺮﻳﺎ‬‫ﺎﺛﺮ وأﻧﺸﻄﺔ اﻟﺒ‬‫ ﺗ‬‫ ﻧﻔﺲ اﻟﻮﻗﺖ ﻋﻠ‬‫ ﺗﺆﺛﺮ اﻟﺤﺮارة واﻟﺮﻃﻮﺑﺔ واﻟﻬﻮاء ﻓ‬، ‫ ﺑﺎﻟﻤﺜﻞ‬.‫ ﻣﺴﺘﻮدع‬‫ ﺣﻘﻞ أو ﻓ‬‫ﻹﻓﺴﺎد اﻟﻄﻌﺎم ﻓ‬.‫ﻴﻤﻴﺎﺋﻴﺔ أﻧﺸﻄﺔ إﻧﺰﻳﻤﺎت اﻟﻐﺬاء‬‫واﻟ‬ 25 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺒﺎرﺷ‬25 Page (25)  Packaged food items: Packaged food items carry date of manufacture or expiry dates to help assure quality. The most commonly used open dates seen on the food products are as under: Sell by date: This is the last recommended day of sale. The date allows for home storage and use. Use by date: This tells how long the product will retain top quality after one buys it. Expiration date: This is the last day the product should be used or eaten. Pack Date: Canned or packaged foods may have pack dates, which tells when the product was processed. This does not tell how long the food will be good. Notes: Packages of food that are not torn or broken should be bought. Canned goods should be free of dents, cracks and bulging lids. Refrigerated food should feel cold and frozen food should be frozen solid. Yanal ALbawarshi 26  made by Echo https://t.me/mkfrbot Page (26) The major types of spoilage that occur in foods are due to microbiological, biochemical, physical and chemical changes. These include: - Growth and activity of microorganisms such as bacteria, yeast and moulds - Activities of food enzymes, present in all raw foods, promote chemical reactions within the food affecting especially the food color, texture and flavor.‫ﻴﻤﻴﺎﺋﻴﺔ‬‫ﻴﻤﻴﺎﺋﻴﺔ واﻟﻔﻴﺰﻳﺎﺋﻴﺔ واﻟ‬‫ اﻟﺘﻐﻴﺮات اﻟ‬، ‫ﺮوﺑﻴﻮﻟﻮﺟﻴﺔ‬‫ اﻟﻤﻴ‬‫ اﻷﻃﻌﻤﺔ ﺗﺮﺟﻊ إﻟ‬‫ ﺗﺤﺪث ﻓ‬‫ اﻷﻧﻮاع اﻟﺮﺋﻴﺴﻴﺔ ﻣﻦ اﻟﺘﻠﻒ اﻟﺘ‬ ‫ ﺟﻤﻴﻊ‬‫ اﻟﻤﻮﺟﻮدة ﻓ‬، ‫ﺘﻴﺮﻳﺎ واﻟﺨﻤﻴﺮة واﻟﻘﻮاﻟﺐ ‐ أﻧﺸﻄﺔ إﻧﺰﻳﻤﺎت اﻟﻐﺬاء‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻣﺜﻞ اﻟﺒ‬‫ ‐ ﻧﻤﻮ وﻧﺸﺎط اﻟ‬:‫وﺗﺸﻤﻞ ﻫﺬه‬ ‫ﻬﺔ‬‫ﻴﻤﻴﺎﺋﻴﺔ ردود اﻟﻔﻌﻞ داﺧﻞ اﻟﻄﻌﺎم اﻟﺬي ﻳﺆﺛﺮ وﺧﺎﺻﺔ ﻟﻮن اﻟﻄﻌﺎم واﻟﻤﻠﻤﺲ و ﻧ‬‫ ﺗﻌﺰﻳﺰ اﻟ‬، ‫اﻷﻃﻌﻤﺔ اﻟﻨﻴﺌﺔ‬ - Inappropriate holding temperatures (heat and cold) for a given food - Gain or loss of moisture - Reaction with oxygen and light causing rancidity and colour changes due to oxidative reactions - Physical stress or abuse - Damage due to pests, insects and rodents etc. ‫‐ درﺟﺎت ﺣﺮارة اﻻﺣﺘﻔﺎظ ﻏﻴﺮ ﻣﻨﺎﺳﺒﺔ )اﻟﺤﺮارة واﻟﺒﺮودة( ﻟﻄﻌﺎم ﻣﻌﻴﻦ ‐ ﻛﺴﺐ أو ﻓﻘﺪان اﻟﺮﻃﻮﺑﺔ ‐ اﻟﺘﻔﺎﻋﻞ ﻣﻊ اﻷﻛﺴﺠﻴﻦ‬ ‫واﻟﻀﻮء ﻣﻤﺎ ﻳﺴﺒﺐ اﻟﺘﻐﻴﺮات واﻟﻠﻮن ﺑﺴﺒﺐ اﻟﺘﻔﺎﻋﻼت اﻟﻤﺆﻛﺴﺪة ‐ اﻟﻀﻐﻂ اﻟﺠﺴﺪي أو ﺳﻮء اﻟﻤﻌﺎﻣﻠﺔ ‐ ﺗﻠﻒ ﺑﺴﺒﺐ اﻵﻓﺎت‬.‫ ذﻟﻚ‬‫واﻟﺤﺸﺮات واﻟﻘﻮارض وﻣﺎ إﻟ‬ - Non -enzymatic reactions in food such as oxidation and mechanical damage 26 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬26 ‫ﻴﺔ‬‫ﺎﻧﻴ‬‫ اﻟﻐﺬاء ﻣﺜﻞ اﻷﻛﺴﺪة واﻷﺿﺮار اﻟﻤﻴ‬‫‐ اﻟﺘﻔﺎﻋﻼت ﻏﻴﺮ اﻟﻤﻨﺸﺄﻳﺔ ﻓ‬ Page (26) How to express shelf life: Best-before date, in relation to a package of food, means the date which signifies the end of the period during which the intact package of food, if stored in accordance with any stated storage conditions, will remain fully marketable and will retain any specific qualities for which express or implied claims have been made. Use-by date, in relation to a package of food, means the date which signifies the end of the estimated period if stored in accordance with any stated storage conditions, after which the intact package of food should not be consumed because of health (nutrient ) or safety reasons. Dr. Yanl AlLbawarshi 27  made by Echo https://t.me/mkfrbot Page (27) Causes of Food Spoilage 1 - biological causes 27 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬27 ‫ ‐ اﻷﺳﺒﺎب اﻟﺒﻴﻮﻟﻮﺟﻴﺔ‬1 ‫أﺳﺒﺎب ﺗﻠﻒ اﻟﻐﺬاء‬ Page (27) Using the FSANZ decision tree to determine when a ‘use-by’ date is needed http://www.foodstandards.gov.au/code/userguide/Pages/datemarking.aspx Yanal ALbawarshi 28  made by Echo https://t.me/mkfrbot Page (28) Spoilage due to growth and activity of microorganisms: Most significant deteriorative changes occur in foods due to microorganisms present in air, soil, water and on foods. They use our food supply as a source of nutrients for their own growth, which results in deterioration of food and render our food supply unfit for consumption. Microbes ‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ اﻟﻤﻮﺟﻮدة‬‫ اﻷﻃﻌﻤﺔ ﺑﺴﺒﺐ اﻷﻃﻌﻤﺔ اﻟ‬‫ ﺗﺤﺪث أﻫﻢ ﺗﻐﻴﻴﺮات ﻓ‬:‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ‬‫ ﺗﻠﻒ ﺑﺴﺒﺐ ﻧﻤﻮ وﻧﺸﺎط اﻟ‬ ‫ ﺗﺪﻫﻮر‬‫ ﻣﻤﺎ ﻳﺆدي إﻟ‬، ‫ ﻳﺴﺘﺨﺪﻣﻮن إﻣﺪاداﺗﻨﺎ اﻟﻐﺬاﺋﻴﺔ ﻛﻤﺼﺪر ﻟﻠﻤﻮاد اﻟﻤﻐﺬﻳﺔ ﻟﻬﻢ اﻟﻨﻤﻮ اﻟﺨﺎص‬.‫ اﻟﻬﻮاء واﻟﺘﺮﺑﺔ واﻟﻤﺎء واﻷﻃﻌﻤﺔ‬‫ﻓ‬ ‫ﺮوﺑﺎت‬‫ اﻟﻤﻴ‬.‫اﻟﻄﻌﺎم و ﺟﻌﻞ إﻣﺪاداﺗﻨﺎ اﻟﻐﺬاﺋﻴﺔ ﻏﻴﺮ ﻻﺋﻘﺔ ﻟﻼﺳﺘﻬﻼك‬ spoil any food in many ways viz. by increasing their number; by utilizing nutrients; by producing enzymatic changes; by contributing off -flavours ; by breakdown of a product; and by synthesis of new compounds. The three major types of microorganisms which cause food spoilage are bacteria, yeasts and moulds. ‫ ﻋﻦ ﻃﺮﻳﻖ إﻧﺘﺎج ﺗﻐﻴﻴﺮات إﻧﺰﻳﻤﻴﺔ ؛ ﺑﻮاﺳﻄﺔ‬.‫ ﺑﺰﻳﺎدة ﻋﺪدﻫﻢ ؛ ﻋﻦ ﻃﺮﻳﻖ اﺳﺘﺨﺪام اﻟﻌﻨﺎﺻﺮ اﻟﻐﺬاﺋﻴﺔ‬.‫ﺗﻔﺴﺪ أي ﻃﻌﺎم ﺑﻌﺪة ﻃﺮق ﺑﻤﻌﻨ‬ ‫ﺎﺋﻨﺎت‬‫ اﻷﻧﻮاع اﻟﺮﺋﻴﺴﻴﺔ اﻟﺜﻼﺛﺔ ﻣﻦ اﻟ‬.‫ ﻋﻦ ﻃﺮﻳﻖ اﻧﻬﻴﺎر اﻟﻤﻨﺘﺞ ؛ و ﻋﻦ ﻃﺮﻳﻖ ﺗﺨﻠﻴﻖ اﻟﻤﺮﻛﺒﺎت اﻟﺠﺪﻳﺪة‬.‫اﻟﻤﺴﺎﻫﻤﺔ ﻗﺒﺎﻟﺔ اﻟﻔﻼﻓﻮر‬.‫ﺘﻴﺮﻳﺎ واﻟﺨﻤﺎﺋﺮ واﻟﻘﻮاﻟﺐ‬‫ اﻟﺒ‬‫ ﺗﺴﺒﺐ ﺗﻠﻒ اﻟﻐﺬاء ﻫ‬‫اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ اﻟﺘ‬ 28 Yanal ALbawarshi ‫ ﺟﺎﻧﺎل أﻟﺒﺎرﺷ‬28 Page (28) Figure 1: How the growth of microorganisms impacts on shelf life and date marking Scenario A: Food supports the growth of both pathogenic and spoilage bacteria during storage; the pathogenic bacteria reach unsafe levels before the food is visibly spoiled Outcome: A ‘use-by’ date is required to ensure the food is not consumed when pathogen levels could be unsafe. Yanal ALbawarshi 29  made by Echo https://t.me/mkfrbot Page (29) Bacteria Yeasts Moulds Factors affecting growth of microorganisms Spoilage due to enzymatic activity Factors affecting enzymatic activity ‫ اﻟﻌﻮاﻣﻞ اﻟﺘ‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﺗﻠﻒ ﺑﺴﺒﺐ اﻟﻨﺸﺎط اﻷﻧﺰﻳﻤ‬‫ ﻧﻤﻮ اﻟ‬‫ ﺗﺆﺛﺮ ﻋﻠ‬‫ﺘﻴﺮﻳﺎ اﻟﺨﻤﺎﺋﺮ اﻟﻘﻮاﻟﺐ اﻟﻌﻮاﻣﻞ اﻟﺘ‬‫ اﻟﺒ‬ ‫ اﻟﻨﺸﺎط اﻷﻧﺰﻳﻤ‬‫ﺗﺆﺛﺮ ﻋﻠ‬ Spoilage due to insects, pests and rodents Spoilage due to chemical reactions Spoilage due to physical factors 29 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬29 ‫ﻴﻤﻴﺎﺋﻴﺔ ﺗﻠﻒ ﺑﺴﺒﺐ اﻟﻌﻮاﻣﻞ اﻟﻤﺎدﻳﺔ‬‫ ﺗﻠﻒ ﺑﺴﺒﺐ اﻟﺤﺸﺮات واﻵﻓﺎت واﻟﻘﻮارض ﺗﻠﻒ ﺑﺴﺒﺐ اﻟﺘﻔﺎﻋﻼت اﻟ‬ Page (29)  Scenario B: Food supports the growth of both pathogenic and spoilage bacteria during storage but the food is visibly spoiled before pathogenic bacteria have reached unsafe levels Outcome: A ‘best-before date’ may be appropriate Yanal ALbawarshi 30  made by Echo https://t.me/mkfrbot Page (30) Sources of microorganisms in food The primary sources of microorganisms in food include: 1. Soil and water 2. Plant and plant products 3. Food utensils 4. Intestinal tract of man and animals ‫ اﻟﻤﻨﺘﺠﺎت‬.2 ‫ اﻟﺘﺮﺑﺔ واﻟﻤﺎء‬.1 :‫ اﻟﻄﻌﺎم‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻓ‬‫ اﻟﻄﻌﺎم ﺗﺸﻤﻞ اﻟﻤﺼﺎدر اﻷوﻟﻴﺔ ﻟﻠ‬‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ ﻓ‬‫ﻣﺼﺎدر اﻟ‬ ‫ اﻟﺠﻬﺎز اﻟﻤﻌﻮي ﻟﻠﺮﺟﻞ واﻟﺤﻴﻮاﻧﺎت‬.4 ‫ اﻟﻐﺬاء‬‫ أواﻧ‬.3 ‫اﻟﻨﺒﺎﺗﻴﺔ واﻟﻨﺒﺎﺗﻴﺔ‬ 5. Food handlers 6. Animal hides and skins 7. Air and dust 30 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬30 ‫ اﻟﻬﻮاء واﻟﻐﺒﺎر‬.7 ‫ اﻟﺤﻴﻮاﻧﺎت واﻟﺠﻠﻮد‬‫ ﻳﺨﺘﺒ‬.6 ‫ ﻣﻌﺎﻟﺠﺎت اﻟﻄﻌﺎم‬.5 Page (30)  Scenario C: The pathogenic bacteria may sometimes be present at very low (safe) levels but do not grow in the food. Spoilage bacteria can grow and the food becomes visibly spoiled Outcome: A ‘best-before’ date is appropriate Yanal ALbawarshi 31  made by Echo https://t.me/mkfrbot Page (31) 31 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺒﺎرﺷ‬31 Page (31)  Principles and Methods of Food Preservation Introduction Food preservation is one of the oldest technologies used by the mankind. The perishable foods like fruits, vegetables, milk, meat and fish etc. deteriorate or decay easily, so considerable amounts of such commodities are wasted in various stages of food supply chain unless special methods are applied for their preservation. Food preservation is a process through which physical and /or chemical agents are used to prevent microbial spoilage of food. Food preservation aims at treating food in a manner to prolong its storage life. In food preservation, efforts are made to: 1- destroy organisms in the food,or 2- Increase the period taken by microorganism to adapt to the food environment before they start to spoil the food. Yanal ALbawarshi 32  made by Echo https://t.me/mkfrbot Page (32) How does food processing influence the spoilage rate and the type of spoilage that occurs? 1. Increase in the number of microorganisms during processing. 2. Destruction of the normal spoilage flora and the introduction of a new microflora. 3. Changes in the intrinsic and extrinsic parameters of the food..2.‫ﺎﺋﻨﺎت اﻟﺤﻴﺔ اﻟﺪﻗﻴﻘﺔ أﺛﻨﺎء اﻟﻤﻌﺎﻟﺠﺔ‬‫ ﻋﺪد اﻟ‬‫ زﻳﺎدة ﻓ‬.1 ‫ ﻣﻌﺪل اﻟﺘﻠﻒ و ﻧﻮع اﻟﺘﻠﻒ اﻟﺬي ﻳﺤﺪث؟‬‫ ﻛﻴﻒ ﺗﺆﺛﺮ ﻣﻌﺎﻟﺠﺔ اﻟﻄﻌﺎم ﻋﻠ‬.‫ اﻟﻤﻌﻠﻤﺎت اﻟﺠﻮﻫﺮﻳﺔ واﻟﺨﺎرﺟﻴﺔ ﻟﻠﻄﻌﺎم‬‫ اﻟﺘﻐﻴﻴﺮات ﻓ‬.3.‫ ﺟﺪﻳﺪ‬microflora ‫ﺗﺪﻣﻴﺮ ﻧﺒﺎﺗﺎت اﻟﺘﻠﻒ اﻟﻄﺒﻴﻌﻴﺔ واﻟﻤﻘﺪﻣﺔ ﻣﻦ‬ 32 Yanal ALbawarshi Janal Albawarshi 32 Page (32)  Principles of Food Preservation All food preservation methods are based upon the general principle of preventing or retarding the causes of spoilage caused by microbial decomposition, enzymatic and non-enzymatic reaction, chemical or oxidative reactions and damage from mechanical causes, insects and rodents etc. Food preservation operates according to three principles, namely: 1- Prevention or delay of microbial decomposition brought out by a- Keeping out microorganisms or asepsis b- Removal of microorganisms e.g. washing, filtration etc. c- Hindering the growth and activity of microorganisms by controlling the conditions required for the growth and activity of microorganisms by use of low temperature, drying, maintenance of anaerobic conditions or chemicals (Inhibition) d- Killing microorganisms by heat or irradiation Yanal ALbawarshi 33  made by Echo https://t.me/mkfrbot Page (33) Bacteria Bacteria are much more difficult to kill than moulds and yeast and are the most common causes of food spoilage. They are present in two forms viz. vegetative and spore, The vegetative forms of bacteria are easily destroyed at boiling temperature whereas spores require harsh treatments like application of ‫ اﺛﻨﻴﻦ‬‫ ﻫﻢ ﻣﻮﺟﻮد ﻓ‬.‫ﺎ ﻟﺘﻠﻒ اﻟﻐﺬاء‬‫ اﻷﺳﺒﺎب اﻷﻛﺜﺮ ﺷﻴﻮﻋ‬‫ اﻟﻘﺘﻞ ﻣﻦ اﻟﻘﻮاﻟﺐ واﻟﺨﻤﻴﺮة وﻫ‬‫ﺘﻴﺮﻳﺎ أﻛﺜﺮ ﺻﻌﻮﺑﺔ ﻓ‬‫ﺘﻴﺮﻳﺎ اﻟﺒ‬‫ اﻟﺒ‬ ‫ ﺣﻴﻦ أن اﻟﺠﺮاﺛﻴﻢ ﺗﺘﻄﻠﺐ‬‫ درﺟﺔ ﺣﺮارة اﻟﻐﻠﻴﺎن ﻓ‬‫ﺘﻴﺮﻳﺎ ﺑﺴﻬﻮﻟﺔ ﻓ‬‫ﺎل اﻟﺒ‬‫ ﻳﺘﻢ ﺗﺪﻣﻴﺮ أﺷ‬‫ اﻟﻨﺒﺎﺗ‬، ‫ وﻳﺒﻮت‬‫ ﻧﺒﺎﺗ‬.‫ﻣﻦ اﻟﻨﻤﻮذﺟﻴﻦ ﺑﻤﻌﻨ‬ ‫ﻋﻼﺟﺎت ﻗﺎﺳﻴﺔ ﻣﺜﻞ ﺗﻄﺒﻴﻖ‬ heat ( 100 ° C) for a long time (six hours) or at 121 ° C under 15 psi pressure for 30 min. 33 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل‬33.‫ دﻗﻴﻘﺔ‬30 ‫ ﻟﻤﺪة‬PSI ‫ ﺿﻐﻂ‬15 ‫ درﺟﺔ ﻣﺌﻮﻳﺔ ﺗﺤﺖ‬121 ‫ درﺟﺔ ﻣﺌﻮﻳﺔ( ﻟﻔﺘﺮة ﻃﻮﻳﻠﺔ )ﺳﺖ ﺳﺎﻋﺎت( أو ﻋﻨﺪ‬100) ‫اﻟﺤﺮارة‬ ‫أﻟﺰارﺷ‬ Page (33) 2- Prevention or delay of self-decomposition of foods by a- Destroying or inactivating food enzymes e.g. blanching, low temperature storage, chemical preservation, drying etc. b- Preventing or delay of chemical reactions e.g. prevention of oxidation with the use of antioxidants as oxygen speeds up decomposition of food and antioxidants deprives food from oxygen. 3- Prevention of damage because of external factors such as insects, rodents, dust, odour, fumes, and mechanical, fire, heat or water damage. Eg. Use of boxes, cartons, and shock absorbing materials, sealed tight, vacuum-packaging etc. Yanal ALbawarshi 34  made by Echo https://t.me/mkfrbot Page (34) Bacteria are classified as aerobic, anaerobic and facultative when they require free oxygen for growth, no oxygen and can grow with or without free oxygen, respectively. On the basis of temperature required for growth, bacteria can be grouped into four types viz. ‫ﻦ أن‬‫ ﻻ أﻛﺴﺠﻴﻦ وﻳﻤ‬، ‫ ﻟﻠﻨﻤﻮ‬‫ اﻟﻼﻫﻮاﺋﻴﺔ واﻟﺨﺎﻟﻴﺔ ﻋﻨﺪﻣﺎ ﺗﺘﻄﻠﺐ ذﻟﻚ أﻛﺴﺠﻴﻦ ﻣﺠﺎﻧ‬، ‫ أﻧﻬﺎ اﻟﻬﻮاﺋﻴﺔ‬‫ﺘﻴﺮﻳﺎ ﻳﺘﻢ ﺗﺼﻨﻴﻔﻬﺎ ﻋﻠ‬‫ اﻟﺒ‬ ‫ﺘﻴﺮﻳﺎ ﺗﻢ ﺗﺠﻤﻴﻌﻬﺎ‬‫ﻮن اﻟﺒ‬‫ﻦ أن ﺗ‬‫ ﻳﻤ‬، ‫ أﺳﺎس درﺟﺔ اﻟﺤﺮارة اﻟﻤﻄﻠﻮﺑﺔ ﻟﻠﻨﻤﻮ‬‫ ﻋﻠ‬.‫ اﻟﺘﻮاﻟ‬‫ ﻋﻠ‬، ‫ اﻷﻛﺴﺠﻴﻦ‬‫ﻳﻨﻤﻮ ﻣﻊ أو ﺑﺪون ﻣﺠﺎﻧ‬.‫ أرﺑﻌﺔ أﻧﻮاع ﺑﻤﻌﻨ‬‫ﻓ‬ 1 - mesophiles , requiring temperature below 38 ° C 2 - obligate thermophiles, requiring temperature 38 to 82 ° C 3 - facultative thermophiles requiring temperature below 38 to 82 ° C 4 - psychrophiles , requiring temperature and at refrigeration temperatures. 34 Yanal ALbawarshi ‫ درﺟﺔ‬82 ‫ إﻟ‬38 ‫ ﺗﺘﻄﻠﺐ درﺟﺔ ﺣﺮارة‬، ‫ ‐ ﻣﻠﺰم ﺣﺮاري‬2 ‫ درﺟﺔ ﻣﺌﻮﻳﺔ‬38 ‫ ﺗﺘﻄﻠﺐ درﺟﺔ ﺣﺮارة أﻗﻞ ﻣﻦ‬، Mesophiles - 1 ، ‫ ‐ اﻟﺨﻠﻔﻴﺎت اﻟﻨﻔﺴﻴﺔ‬4 ‫ درﺟﺔ ﻣﺌﻮﻳﺔ‬82 ‫ إﻟ‬38 ‫ ‐ اﻟﺘﻤﻴﻴﺰ اﻟﺤﺮاري اﻻﺧﺘﻴﺎري اﻟﺬي ﻳﺘﻄﻠﺐ درﺟﺔ ﺣﺮارة أﻗﻞ ﻣﻦ‬3 ‫ﻣﺌﻮﻳﺔ‬ ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬34.‫ﺗﺘﻄﻠﺐ درﺟﺔ ﺣﺮارة وﺗﺒﺮﻳﺪ درﺟﺎت اﻟﺤﺮارة‬ Page (34)  (1). Inhibition principle In this principle, food preservation is achieved by inhibition of growth and multiplication of microorganisms. The inhibition principle can be achieved by any of the following methods: (a). Reduction of water activity e.g. By drying and salting (b). Reduction in pH e.g. by fermentation and addition of acids. (c). Use of preservatives, e.g. sodium benzoate (d). Use of low temperatures (chilling or freezing) (e). Smoking – which has a drying and preservative effect. 2- the killing principle methods employed to achieve A- Heat treatment: through pasteurization or sterilization B- Irradiation with either ionizing or electromagnetic radiation e.g gamma rays, cobalt 60 radioactive particles. Radiations kill microorganisms by destruction of DNA and by creating toxic reactive compounds in a medium and in microbial cells C- Use of gases: by use of ethylene oxide or ozone. The gases destroy both vegetative cells and spores. Yanal ALbawarshi 35  made by Echo https://t.me/mkfrbot Page (35) The most common bacteria causing significant reductions in shelf life of fruits and vegetables is the soft rotting species of the genus Erwinia. Under suitable conditions they produce large quantities of extracellular enzymes which rapidly macerate the tissue which gives unpleasant off -odours. Some bacteria are also useful particularly in food processing. ‫ اﻷﻧﻮاع اﻟﻤﺘﻌﻔﻨﺔ اﻟﻨﺎﻋﻤﺔ ﻣﻦ ﺟﻨﺲ‬‫ ﻣﺪة اﻟﺮف ﻣﻦ اﻟﻔﻮاﻛﻪ واﻟﺨﻀﺮوات ﻫ‬‫ا ﻓ‬‫ﺎ ﻛﺒﻴﺮ‬‫ ﺗﺴﺒﺐ اﻧﺨﻔﺎﺿ‬‫ﺎ اﻟﺘ‬‫ﺘﻴﺮﻳﺎ اﻷﻛﺜﺮ ﺷﻴﻮﻋ‬‫ اﻟﺒ‬ ‫ ﻏﻴﺮ‬‫ ﺗﻌﻄ‬‫ اﻷﻧﺴﺠﺔ اﻟﺘ‬macerate ‫ ﺑﺴﺮﻋﺔ‬‫ ﻇﻞ ﻇﺮوف ﻣﻨﺎﺳﺒﺔ ﻳﻨﺘﺠﻮن ﻛﻤﻴﺎت ﻛﺒﻴﺮة ﻣﻦ اﻹﻧﺰﻳﻤﺎت ﺧﺎرج اﻟﺨﻠﻴﺔ اﻟﺘ‬‫ ﻓ‬.‫إروﻳﻨﻴﺎ‬.‫ ﻣﻌﺎﻟﺠﺔ اﻷﻏﺬﻳﺔ‬‫ﺎ ﺧﺎﺻﺔ ﻓ‬‫ﺘﻴﺮﻳﺎ ﻣﻔﻴﺪة أﻳﻀ‬‫ ﺑﻌﺾ اﻟﺒ‬.‫ﺳﺎرة ﺧﺎرج‬ For example - aerobic bacteria like Acetobacter aceti used in vinegar production and lactic acid bacteria like Lactobacillus plantarum , Pediococcus cerevisiae, Leuconostoc mesenteroides etc. produce lactic acid by fermentation of carbohydrates. 35 Yanal ALbawarshi ‫ﺘﻴﺮﻳﺎ ﺣﻤﺾ اﻟﻠﺒﻨﻴﻚ ﻣﺜﻞ‬‫ إﻧﺘﺎج اﻟﺨﻞ وﺑ‬‫ اﻟﻤﺴﺘﺨﺪﻣﺔ ﻓ‬acetobacter aceti ‫ﺘﻴﺮﻳﺎ اﻟﻬﻮاﺋﻴﺔ ﻣﺜﻞ‬‫ ﺳﺒﻴﻞ اﻟﻤﺜﺎل ‐ اﻟﺒ‬‫ﻋﻠ‬ ‫ ذﻟﻚ ﻳﻨﺘﺞ ﺣﻤﺾ‬‫ وﻣﺎ إﻟ‬Plantarum ، pediococcus cerevisiae ، leuconostoc mesenteroides ‫اﻟﻼﻛﺘﻮﺑﺎﺳﻴﻠﻮس‬ ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬35.‫ﺮﺑﻮﻫﻴﺪرات‬‫اﻟﻠﺒﻨﻴﻚ ﻋﻦ ﻃﺮﻳﻖ ﺗﺨﻤﻴﺮ اﻟ‬ Page (35)  Methods of Food Preservation The different preservation methods commonly employed are as discussed below: A- Asepsis Asepsis is a process of keeping microorganisms out of food. An aseptic environment can be created by 1- Proper packaging of the product, which separates the internal environment from the surroundings. 2- Maintenance of general cleanliness and sanitary conditions while processing and handling the product from raw material to finished stage. B- Removal of microorganisms It is well known fact that microbes are everywhere, number of microorganisms can be reduced considerably. Such steps include: 1- Washing, 2- Trimming ingredients, 3- Discarding dirt, 4- Filtering, 5- Centrifugation, 6- Sedimentation Yanal ALbawarshi 36  made by Echo https://t.me/mkfrbot Page (36) yeasts Yeasts require less moisture and acidic pH to grow and do not grow in alkaline medium. Yeasts grow under moderate temperature ( 25 -30 ° C) in sugar solution of low concentration. Most of the yeasts usually do not grow in media containing more than 65 percent of sugar or 0.5 percent acetic acid. ‫ ﺗﻨﻤﻮ اﻟﺨﻤﺎﺋﺮ ﺗﺤﺖ‬.‫ اﻟﻮﺳﻂ اﻟﻘﻠﻮي‬‫ اﻟﺨﻤﺎﺋﺮ اﻟﺨﻤﻴﺮة ﺗﺘﻄﻠﺐ رﻃﻮﺑﺔ أﻗﻞ ودرﺟﺔ اﻟﺤﻤﻮﺿﺔ اﻟﺤﻤﻀﻴﺔ ﻟﻠﻨﻤﻮ وﻻ ﺗﻔﻌﻞ ذﻟﻚ ﺗﻨﻤﻮ ﻓ‬ ‫ وﺳﺎﺋﻞ اﻹﻋﻼم‬‫ ﻣﻌﻈﻢ اﻟﺨﻤﺎﺋﺮ ﻋﺎدة ﻻ ﺗﻨﻤﻮ ﻓ‬.‫ﺮ ﻣﻦ ﺗﺮﻛﻴﺰ ﻣﻨﺨﻔﺾ‬‫ ﻣﺤﻠﻮل اﻟﺴ‬‫ درﺟﺔ ﻣﺌﻮﻳﺔ( ﻓ‬30-25) ‫ﻣﻌﺘﺪﻟﺔ درﺟﺔ اﻟﺤﺮارة‬.‫ اﻟﻤﺌﺔ ﺣﻤﺾ اﻷﺳﻴﺘﻴﻚ‬‫ ﻓ‬0.5 ‫ﺮ أو‬‫ اﻟﻤﺌﺔ ﻣﻦ اﻟﺴ‬‫ ﻓ‬65 ‫ ﺗﺤﺘﻮي أﻛﺜﺮ ﻣﻦ‬‫اﻟﺘ‬ Heating at 60 ° C for a few minutes is sufficient to destroy most species of yeasts. Boiling destroys yeast cells and spores effectively. 36 Yanal ALbawarshi 36.‫ اﻟﻐﻠﻴﺎن ﻳﺪﻣﺮ ﺧﻼﻳﺎ اﻟﺨﻤﻴﺮة واﻟﺠﺮاﺛﻴﻢ ﺑﻔﻌﺎﻟﻴﺔ‬.‫ ﻟﺘﺪﻣﻴﺮ ﻣﻌﻈﻢ أﻧﻮاع اﻟﺨﻤﻴﺮة‬‫ﻔ‬‫ درﺟﺔ ﻣﺌﻮﻳﺔ ﻟﺒﻀﻊ دﻗﺎﺋﻖ ﻳ‬60 ‫اﻟﺘﺴﺨﻴﻦ ﻋﻨﺪ‬ ‫ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬ Page (36) C- Maintenance of anaerobic conditions/ packaging Packaging food in a vacuum environment, usually in an air-tight bag or bottle results in anaerobic environment. As bacteria need oxygen for survival, the vacuum environment in the package slows down the spoilage by them. D- Drying It refers to removal of water from the food. Dried foods are preserved because the available moisture level is so low that the microorganisms cannot grow and the enzyme activity is also controlled. Drying can be accomplished by a number of methods viz. sun drying, mechanical/ artificial drying and freeze drying etc. Dried foods are compact and lightweight; do not require refrigeration and last much longer than the fresh foods. Dried foods should be stored in airtight containers to prevent moisture from rehydrating them and allowing microbial growth. Yanal ALbawarshi 37  made by Echo https://t.me/mkfrbot Page (37) Some yeasts are very useful in making bread, beer, wine, vinegar and many other fermented products. Yeasts are responsible for fermentation of fruits and fruit products. During active fermentation, yeast can be recognized by formation of bubbles of carbon dioxide gas on the surface of the product. Some of yeasts which grow on fruits are Saccharomyces, Candida ‫ اﻟﺨﻤﺎﺋﺮ ﻣﺴﺆوﻟﺔ ﻋﻦ‬.‫ ﺻﻨﻊ اﻟﺨﺒﺰ واﻟﺒﻴﺮة واﻟﻨﺒﻴﺬ واﻟﺨﻞ واﻟﻌﺪﻳﺪ ﻣﻦ اﻟﻤﻨﺘﺠﺎت اﻟﻤﺨﻤﺮة اﻷﺧﺮى‬‫ ﺑﻌﺾ اﻟﺨﻤﺎﺋﺮ ﻣﻔﻴﺪة ﻟﻠﻐﺎﻳﺔ ﻓ‬ ‫ﻮﻳﻦ ﻣﻦ ﻓﻘﺎﻋﺎت ﻏﺎز ﺛﺎﻧ‬‫ اﻟﺨﻤﻴﺮة ﻋﻦ ﻃﺮﻳﻖ اﻟﺘ‬‫ﻦ اﻟﺘﻌﺮف ﻋﻠ‬‫ ﻳﻤ‬، ‫ أﺛﻨﺎء اﻟﺘﺨﻤﻴﺮ اﻟﻨﺸﻂ‬.‫ﺗﺨﻤﻴﺮ اﻟﻔﻮاﻛﻪ وﻣﻨﺘﺠﺎت اﻟﻔﺎﻛﻬﺔ‬ ‫ اﻟﻤﺒﻴﻀﺎت‬، saccharomyces ‫ اﻟﻔﻮاﻛﻪ ﻫ‬‫ ﺗﻨﻤﻮ ﻋﻠ‬‫ ﺑﻌﺾ اﻟﺨﻤﺎﺋﺮ اﻟﺘ‬.‫ ﺳﻄﺢ اﻟﻤﻨﺘﺞ‬‫ﺮﺑﻮن ﻋﻠ‬‫أﻛﺴﻴﺪ اﻟ‬ etc. Saccharomyces generally spoils low sugar products whereas Candida is responsible for spoilage of high acid foods, salty foods and butter etc. Some yeasts which are like true yeast but do not form spores are known as pseudo -yeasts. This type of yeast is not suitable for ‫ﺮ اﻟﻤﻨﺨﻔﻀﺔ ﺑﻴﻨﻤﺎ اﻟﻤﺒﻴﻀﺎت ﻣﺴﺆوﻟﺔ ﻋﻦ ﺗﻠﻒ اﻷﻃﻌﻤﺔ اﻟﺤﻤﻴﻤﺔ اﻟﻌﺎﻟﻴﺔ‬‫ﻞ ﻋﺎم ﻣﻨﺘﺠﺎت اﻟﺴ‬‫ ﻳﻔﺴﺪ ﺑﺸ‬saccharomyces.‫إﻟﺦ‬.‫ﻞ ﺟﺮاﺛﻴﻢ اﻟﻤﻌﺮوﻓﺔ ﺑﺎﺳﻢ اﻟﺰاﺋﻔﺔ‬‫ﻦ ﻻ ﺗﺸ‬‫ ﺗﺸﺒﻪ اﻟﺨﻤﻴﺮة اﻟﺤﻘﻴﻘﻴﺔ وﻟ‬‫ ذﻟﻚ ﺑﻌﺾ اﻟﺨﻤﺎﺋﺮ اﻟﺘ‬‫واﻷﻃﻌﻤﺔ اﻟﻤﺎﻟﺤﺔ واﻟﺰﺑﺪة وﻣﺎ إﻟ‬ ‫ﻫﺬا اﻟﻨﻮع ﻣﻦ اﻟﺨﻤﻴﺮة ﻏﻴﺮ ﻣﻨﺎﺳﺐ ل‬ fermentation as they produce off -flavours and cloudiness. 37 Yanal ALbawarshi ‫ ﻳﺎﻧﺎل أﻟﺒﻮارﺷ‬37.‫ واﻟﻐﻴﻮم‬flavours ‫اﻟﺘﺨﻤﻴﺮ ﻷﻧﻬﺎ ﺗﻨﺘﺞ ﻗﺒﺎﻟﺔ‬ Page (37) E- Smoking In this method, foods are exposed to smoke by burning some special kinds of wood, which has two main purposes, 1- adding desired flavoring and 2- preserving. Smoke contains a- chemicals like formaldehyde, which is bactericidal. and b- also the dehydration occurring due to smoking is responsible for its preservative action. The smoke is obtained by burning wood like oak, maple, walnut and mahogany under low breeze/ wind. Most meat is smoked after curing to aid their preservation. Examples of smoke preserved foods are smoked beef, ham, bacon, fish and meat. F- Food concentration Relatively few liquid foods are preserved by concentration, involving preservative action of reduction in water activity (aw) and development of osmotic pressure, which retard the microbial growth and enzymatic reactions. Concentration of food is usually done for many reasons: 1- reduction in volume and weight; 2- reduction in packaging, storage and transport costs; 3-better microbial stability; and 4- convenience. Examples of food preserved by concentration are tomato paste, fruit juice concentrate, soup and condensed milk. NOTE: The rate of heating should be controlled to prevent localized burning of the product, particularly when it has become thickened towards the end of boiling. Yanal ALbawarshi 38  made by Echo https://t.me/mkfrbot Page (38) Moulds Moulds are multicellular filamentous fungi. They grow on foods with their fuzzy or cottony appearance, sometimes colored. Moulds are made up of mycelium and spores. They grow in a network of hair like fibres called mycelia and ‫ ﺑﻌﺾ‬‫ ﻣﻠﻮﻧﺔ ﻓ‬، ‫ اﻷﻃﻌﻤﺔ ﻣﻊ ﻣﻈﻬﺮﻫﺎ اﻟﻐﺎﻣﺾ أو اﻟﻘﻄﻦ‬‫ ﻳﻨﻤﻮون ﻋﻠ‬.‫ اﻟﻔﻄﺮﻳﺎت اﻟﺨﻴﻄﻴﺔ ﻣﺘﻌﺪدة اﻟﺨﻼﻳﺎ‬‫ اﻟﻘﻮاﻟﺐ اﻟﻘﻮاﻟﺐ ﻫ‬ ‫ و‬Mycelia ‫ﺔ ﻣﻦ اﻟﺸﻌﺮ ﻣﺜﻞ اﻷﻟﻴﺎف ﺗﺴﻤ‬‫ ﺷﺒ‬‫ ﻫﻢ ﺗﻨﻤﻮ ﻓ‬.‫ﻮن ﻣﻦ اﻟﻔﻄﺮﻳﺎت واﻟﺠﺮاﺛﻴﻢ‬‫ اﻟﻘﻮاﻟﺐ ﺗﺘ‬.‫اﻷﺣﻴﺎن‬ send up fruiting bodies that yield spores. Some of common moulds are Aspergillus, Penicillium , Rhizopus and Heliminthosporium. 38 Yanal ALbawarshi ‫ و‬Aspergillus ، penicillium ، rhizopus ‫ ﺑﻌﺾ اﻟﻘﻮاﻟﺐ اﻟﺸﺎﺋﻌﺔ ﻫ‬.‫ ﺟﺮاﺛﻴﻢ‬‫ ﺗﻌﻄ‬‫أرﺳﻞ ﺟﺜﺚ اﻟﺜﻤﺎر اﻟﺘ‬ ‫ ﻳﺎﻧﺎل أﻟﺰارﺷ‬Heliminthosporium. 38 Page (38) G- Use of high sugar or salt content 1- Sugaring A strong sugar solution (about 68% or more) draws water from the microbial cells and thus, inhibits the growth of microbes. Examples of food preserved by high sugar concentrations are fruits in heavy sugar syrup, jams, jellies, marmalades, candies and sweetened condensed milk. 2- Pickling Pickling uses the salt combined with the acid, such as acetic acid (vinegar). Some of the fruits and vegetables, which are generally pickled, are raw mangoes, limes, cucumber, etc. 3- Salting or curing Salting is being done in case of meat and fish preservation since ancient times. Curing preserves the food by drawing moisture from the meat through osmosis and makes it unavailable for microbial growth and enzyme action. Nitrates and nitrites are also often used to cure meat, which contribute the characteristic pink colour to meat, as well as inhibition of Clostridium botulinum. Yanal ALbawarshi 39  made by Echo https://t.me/mkfrbot Page (39) They are strictly aerobic in nature and require less available moisture than yeast and bacteria and can grow well at 25 -30 ° C. Their growth can be seen only on the surface of food. Moulds prefer sugar containing substances like jam, jelly, preserves and other sweet products. They can grow at wide range of pH ( 2 to 8.5 ) but majority grow ‫ درﺟﺔ ﻣﺌﻮﻳﺔ‬130-25 ‫ﻞ ﺟﻴﺪ ﻓ‬‫ﻦ أن ﺗﻨﻤﻮ ﺑﺸ‬‫ﺘﻴﺮﻳﺎ وﻳﻤ‬‫ اﻟﻄﺒﻴﻌﺔ وﺗﺘﻄﻠﺐ أﻗﻞ ﻣﺘﺎﺣﺔ اﻟﺮﻃﻮﺑﺔ ﻣﻦ اﻟﺨﻤﻴﺮة واﻟﺒ‬‫ ﻃﺒﻴﻌﻴﺔ ﻓ‬‫ ﻓﻬ‬ ‫ اﻟﻤﺤﻔﻮﻇﺎت‬، ‫ واﻟﻬﻼم‬، ‫ ﻣﻮاد ﻣﺜﻞ اﻟﻤﺮﺑ‬‫ ﺗﺤﺘﻮي ﻋﻠ‬‫ﺮ اﻟﺘ‬‫ اﻟﻘﻮاﻟﺐ ﺗﻔﻀﻞ اﻟﺴ‬.‫ ﺳﻄﺢ اﻟﻄﻌﺎم‬‫ﻦ رؤﻳﺔ ﻧﻤﻮﻫﺎ ﻓﻘﻂ ﻋﻠ‬