Post Harvest Notes PDF

1\. Food loss & waste: \* 14% is lost before it reaches consumers & 17% is wasted every year. \# This is because of lack of effective cold chain. \* Perishable food should kept at cool temperature controlled environment, throughout production, aggregation and storage, processing, marketing and di...

1\. Food loss & waste: \* 14% is lost before it reaches consumers & 17% is wasted every year. \# This is because of lack of effective cold chain. \* Perishable food should kept at cool temperature controlled environment, throughout production, aggregation and storage, processing, marketing and distribution. \* This temperature supply chain of food called food cold chain. \* However, cooling technologies can consume alot of electricity, generated largely from fossil fuels. \* Ozone depleting substances are ODS and HFC\'s (Hydroflurocarbons) which are powerful green house gasses. \* Nowadays, cold chain contributes around 4% of global GHG emission effecting the climate change and food production. \* Lack of access to food cold chain impacts food security, livelehoods and limits acess to markets. To improve food cold chain: \* In 1987, nations have signs the montereal protocol to help save the ozone layer, which includes phasing out of ODS\'s in various sectors like cooling technologies \* phasing down HFC\'s will also addresses energy efficiency issues. \* Building sustainable food cold chain solutions which could improve the access of energy for cooling to food value chain, developing & gathering data, improving technical capacity, updating policies, efficiency improvements and financing. \* Sustainable food cold chain will help work towards SDG\'s and supports farmer\'s, fisher livelihood's as well as ensuring more nutritious food reaches everyone. 2\. understanding temperature control: \* Temperature control is essential to ensure the minimizing the multiplication of bacteria. \* Keeping food outside the temperature where bacteria multiply, the risk of food spoilage is reduced and reduces the risk of food poisoning. \* An important principle in temperature control is called the cold chain. \* Food must be kept at temperature below 5 degree Celsius whether is stored, transported or handled. The food goes above 5 degree Celsius this is called breaking the cold chain. \* Breaking the cold chain increases the risk of contamination. \# High risk foods: Must kept chilled at below 5 degree Celsius or kept hot above 65 degree Celsius to ensure the food is not in the danger zone. \* Exceptions to keeping food below 5 degree Celsius includes: \* Food that is on display maybe displayed for more than 4 hours, but the 4 hours may includes preparing and packing the foods. \* Food that requires ripening or maturing like cheese ( The ingredients should be refrigerated once the process is done). \# Foods that not requires temperature control: \* Some food can be kept at room temperature that is about 20 degree Celsius which are low risk foods like raw whole fruits & vegetables. \* These foods are stored in chilled conditions to minimize spoilage and increasing the raw whole fruits and vegetables shelf-life, also quality. \# Frozen foods: \* Should be kept at -18 degree Celsius and should be frozen solid when delivered, also when food is displayed and transported. \* Storing the frozen food at -18 degree Celsius is very important for maintain the quality. \* Each food type should be stored separately in it\'s own section like dairy, meat, poultry and fish. \# Measuring the temperature of foods: \* When measuring the foods, the core measurement needs to be taken which is the temperature in the middle of the food. because sometime the food is hot from outside but not in the middle. \* For accurate core measurement, using a tip sensitive thermometer of probe is required and can be inserted in the foods. \* Cleaning & disinfecting of the thermometer should be considered before inserting it in foods to avoid inserting forbidden bacteria\'s. 3\. Blast freezers: \* The first part includes core & skin temperature which are lies between -15 to 5 degree Celsius. \* Then the product temperature lies between -20 to 30 degree Celsius, where it decreases to -20 dramatically. 4\. blast freezing: \* It is a process of pushing cold air at high velocity across the food (chicken). \* The temperature is lowered down rapidly by blast freezing technology. \* The temperature will be changed from chill condition (4-8 degree Celsius) into frozen (-18 degree Celsius) after blast freezing process. \* The blast freezer temperature is set up to -40 degree Celsius & it takes 30-90 minutes to reach that temperature. \* While the food ( chicken) is stored up to 4-8 hours in blast freezer to reach -18 degree Celsius. \# Why blast freezing?? \* When water crystallizes into ice during freezing process, rapid freezing keeps the ice crystals size to minimum, therefore the longer freezing process, the larger ice crystals. \* In addition, Larger ice crystals can cause cell bursting, which effect quality & flavor of food (chicken). \* This process is implemented for bacterial protection, and preserve nutrient in food (chicken). \* At -18 degree Celsius bacteria cannot develop while keeping chicken fresh. \* After 8 hours the frozen chicken are taken out for packaging process in carton boxes. Then, the packaging is stored in cold room at -18 degree Celsius. \* Hence, the frozen chicken can last up to 12 months. Delivered by truck that maintain a temperature of -18 degree Celsius and ensure end to end cold chain network 5\. Food packaging technology \* purpose of packaging: keeping food safe for consumption and increases food storage life. \* Diverse forms of packaging throughout the history. \* Canning method is one of preservation methods that includes boiling foods, sealing it in airtight glass containers. \* packaging technology Plays a significant role in ensuring the continued viability of perishable foods and reducing the likelihood of spoilage. \* mind-blowing breakthrough includes electronic tongues that can taste things, or nanoparticles that can fight bacteria. \# What are the primary roles that food packaging plays: \* Packaging keeps food safe by isolating it contents from the elements. \* Packaged foods last longer in storge. \* Food packaging can prevent food from being spoiled or unsafe from biological agents like rats, insect's germs and bacteria. \* Food packaging educate people about the product. 1\. Paper and paperboard: \# The most common types of packaging, and they are account about 34% of the market. \# Rice, lentils and flour are packaged in these substances. \# There are inexpensive, quickly decomposes in the environment. 2\. Plastic: \# Rigid and flexible are the 2type of plastic packaging. \# Advantages: low cost, shape versatility, lightweight and processing simplicity. 3\. Glass: \# Many liquid foods are stored in glass bottles because of their mysterious nature. \# There are chemically harmless. \# Tends to be cumbersome due to its weight. \# Fragile and tends to shatter very easily. 4\. Metals: \# Metal containers can hold both dry and wet foods (beverages & canned foods). \# Provide alternative to glass that retains many latter of advantages. Futuristic food packaging: 1\. Edible packaging: edible packaging has been created by Edward which he created many edible and delightful food containers, including pumpkin soup, spinach membrane, lemon juice in lemon membrane and melting chocolate in cherry membrane. 2\. Micro-packaging: Microfilm by nanotechnology which can revolutionize food packaging. Where the material is composed of water and 70% clay particles and its thousands times thinner than human hair. In addition it\'s environmentally friendly and has preservation capabilities of glass. 3\. Intelligent packaging: Preservative innovative packaging are developed to save perishable foods. Super sensors that can determine if the food is tainted. 4\. Anti-microbial packaging: Doing more than keeping bacteria out of food but it kills them. Antibiotic killing paper covered with silver nanoparticles which can be used to prevent bacteria from spreading to food 6\. Food preservation: \* Food is harvested in large quantities. \* Rooting occurs when bacteria & fungi attacks food. \* Pests like weevils can destroy foods. \* Any surplus food should be stored properly. \* Food preservation is process of storing food properly for a certain period of time to avoid being spoiled. \* Traditional methods & modern methods are the main preservation methods. 1\. Traditional methods includes: \# Smoking: Method for preserving meats like beef, mutton, pork and fish. This process keeps bacteria & fungi away. The meat is stored and sealed in dry container or polyethene bag. \# Salting: meat , fish and other foods can be preserved by salting. \# Drying: Drying removes most of the water. Kales and Sukuma wiki and other vegetables can be dried. Method for preserving food like fish, meat, grains, fruits and herbs. \# using honey: Does not allow air and bacteria to reach the food. For example fruits and boiled meat. This method can preserve foods for many years. \# low temperature: Food remains fresh when stored at low temperature. For example fresh milk \# A charcoal cooler: storage device similar to refrigerator. preserves food in area that has no electricity. Uses charcoal & water to remain cool. \# Using Ashes: Peas, beans, green grams and potato tubers can be preserved by this method. keeps away pests like ants & weevils. 2\. Modern methods includes: \# Drying: preserves foods like rice, tea leaves and coffee berries. \# freezing: preserves foods under very low temperature below 0 degree Celsius. Done by using deep freezer in refrigerators. Foods preserved meat, fruits, vegetables and cooked foods. before storing them in deep freezer, the foods are sealed in containers or polyethene bags to prevent them from being dried by cold dry air from the freezer. \# Refrigeration: keeps food at low temperature between 0-8 degree Celsius. For example meat, fish, milk, vegetables, fruits and cooked foods. Hospitals, schools and factories use cold rooms to store large amount of foods for longer period of time. \# Canning: Mainly used method in factories. Foods preserved like canned beans, meat, fruit juice and jams. Foods are heated at high temperature to kill germs and to remove air then put it in cans and sealed. 3\. Proper storage of foods: \# Storing foods properly let the food stays for a long period of time. \# Salt, pepper, sugar and tea leaves should be placed in shelves. \# milk , fish and meat should be kept covered in the refrigerator. \# Foods should be stored in a cupboard fitted to allow free circulation of air. \# Dried foods like flour, grains and rice should be kept in containers with tight fitting lids. \# maize and beans in large amount should be kept in plastic containers. 7\. Methods of preserving meat: \# Cold storage: cold temperature halts the activity & growth of microorganisms effectively increasing the meat\'s shelf-life. \# canning: Packaging meats in cans and sealing under high temperature & pressure, which creates a vacuum where the bacteria can\'t survive. \# Smoking meat: Kills bacteria and slow down the growth of others. \# Drying: Inhospitable environment for bacteria and extending shelf-life of meat, when meat is dried. \# Salting: Coating the meat with salt creates an environment too salty for bacteria to survive, effectively preserving the meat. \# Boiling: Regular boiling of meat at intervals of 12 hours kills most of bacteria and reduces their multiplication. 8\. Methods of preserving milk: \# Cold storage: Deter the growth of microorganisms, therefore helps milk to stay fresh longer. \# Drying milk: By Removing all moisture & converting milk to powder (Most bacteria cannot survive in dry matter). \# Fermentation: Fermented milk can increases the shelf-life. \# Pasteurization/ Boiling: Partially sterilizes milk by killing off growing microorganisms like bacteria which reduces the multiplication of the population. Therefore, extends the shelf-life of milk. 9\. How milk powder is made? \# Silage is used as nutritious feed for cows. \# Milking is the first stage which is done by the farmers where they collect milk from cows. \# The machine used for milking are cleaned after and before each milking session to maintain the quality & safety of milk. \# The modern milking process allows efficient milk collection to produce milk powder in large scale. \# The cows reunited with their calves which is important for ensuring the health well-being of both cows and calves. \# After collection & refrigeration of milk, its tested for quality & purity. \# The milk undergoes through quality checks for contaminants, bacteria, butterfat, and protein levels. \# Once the milk passes through the checks successfully, they go through efficient processing & storage. \# Then pasteurization of milk: heating milk for specific time and temperature to ensure its safe for human consumption and harmful bacteria are killed. \# HTST pasteurization: heating at 70 degree Celsius for 15 second. \# Concentration process: Water is removed to enhance milk powder shelf-life. \# preheating: At approximately 60 degree Celsius preserve the taste, then milk is sprayed in heated chamber ( Where hot air evaporates 80% of moisture leaving concentrated milk product with heightened stability & longevity). \# The concentrated milk is then dried to create milk powder, where the milk is injected under high pressure into drying tower, where its mixed with hot air at a temperature around 220 degree Celsius. \# Soy lecithin is added to ensure that the milk powder is easily dissolved in water. \# Drying process guarantees the stability & longevity milk powder, which makes it suitable for long term storage. \# once the milk powder is ready, it goes through crucial testing quality process to ensure the freshness & safety. \# Afterwards, the milk powder is ready for packaging, proper packaging is crucial for preserving the quality & shelf-life of milk powder. \# packaging protects the product from light, air & humidity. In addition, it ensures the milk powder remains safe & hygienic. \# Sealed and labeled so the consumers have all the necessary information about the product. \# The top consumers of milk powder are China, India, Indonesia, Vietnam and Mexico. 10\. Fish preservation: 1\. Sizes & market forms of dressed fish: \# live fish \# Round or whole fish ( most species are sold in this form). \# Drawn fish ( Sold with internal organs removed). \# steaks ( Bigger like tanigue, tuna, maya-maya and Lapu-Lapu/ sold chopped or cut along the cross section). \# Dressed fish ( The scales, internal organs, fins head and tail are removed). \# Fillets ( Most common cut available from any fish , either round or flat). Types of fillets: \# Butterfly fillets ( Smaller whole fish can be prepared by removing head and cutting through their back or belly side of the fish) \# Quarter cut fillets ( single flat fish fillet that is cut in half lengthways into quarter fillet). \# Sticks ( cut from fillet or steaks/ usually from fish that has been minced and shaped, breaded and frozen) 2\. Steps in preparing the fish: \# beheading ( remove head by cutting it off on a slanted line following the gills) \# Gutting ( cut from the gill cavity along the ventral fold to the anal vent) \# Bleeding ( most species of fish must be thoroughly bled). \# Cutting ( the fish is cut depends on local custom). Preservation methods: \# Fish curing includes: \# Salting ( Adding salt to fish until it seeps through the fresh forcing out water from the flesh) it also includes dry salting ( direct salting by granules of salt that covers the surface of fish completely), brine solution ( Solution of salt & water). tools and equipment's used for salting: \# Fish scaler ( used to remove the scales of fish) \# Knives ( used for cutting and eviscerating the fish) \# Measuring spoons ( measure the preservatives & ingredients needed) \# Oil drum ( Container to keep salted fish during the process) \# Wooden basin ( used in mixing salt and fish) \# Wooden vat (For brine salting large quantities of fish) \# Wooden basket ( Carrying or transporting material\'s and finished products \# Drying: one of the oldest methods of preserving fish, whihc is done by exposing fish to heat or sun by mechanical kiln or driers. There are types of drying: a\. Sun drying ( Fish is sliced and spread on a tray or mat then exposed to sun to dry out) b\. Artificial drying ( fish is dried by exposure to hot air in oven or constructed drier) Tools and equipment's used for drying: \# bamboo basket (used as containers of dried fish products) \# Bamboo tray (used for holding fish when drying) \# drying platform ( used in holding trays and racks when drying fish) \# Drying shed ( used to protect dried fish from the rain) \# Oven ( used for artificial sun drying) \# Smoking : process of exposing fish to wood smoke until it golden brown. \# pickling : method of preserving fish involves treating the fiah with vinegar & spices. Methods of pickling: \# Kilaw: treating fish with vinegar, garlic and ginger. \# Marinating: soaking fish in calamansi juice, soy sauce, garlic and black pepper. Basic ingredients in pickling: \# Vinegar ( enhance the quality and increases the freshness of fish) \# Sugar (adds sweetness to fish ) \# Spices (includes whole cloves, whole spice, celery seeds, mustard seeds, cinnamon sticks, pepper corn and other ingredients that improves the taste of fish product) \# Canning: preservation or sterilization of food in hermetically sealed can or glass container by heating it evenly at a specific temperature. \# Packaging: lengthens the life of foods