Food preservation and packings

Ranjitha R 4GW20EC413.

     FOOD PRESERVATION AND PACKING               

                   Food Preservation

             Food preservation is the process of treating and handling food to stop or slow down food spoilage, loss of quality, edibility, or nutritional value and thus allow for longer food storage.

Preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other microorganisms, as well as retarding the oxidation of fat which cause rancidity.

          Methods of Food Preservation

             A number of methods of prevention can be used that can either totally prevent, delay, or otherwise reduce food spoilage. Preservatives can expand the shelf life of food and can lengthen the time long enough for it to be harvested, processed, sold, and kept in the consumer’s home for a reasonable length of time.

Maintaining or creating nutritional value, texture and flavor is an important aspect of food preservation, although, historically, some methods drastically altered the character of the food being preserved. In many cases these changes have now come to be seen as desirable qualities, as with cheese, yogurt, and pickled onion.  

                         DRIYING                                

         Drying is one of the most ancient food preservation techniques, which reduces water activity sufficiently to prevent bacterial growth.

      REFRIGERATION   (or)  FREE ZING

 Refrigeration preserves food by slowing down the growth and reproduction of microorganisms and the action of enzymes which cause food to rot.

                          FREEZING

         Freezing is also one of the most commonly used processes for preserving a very wide range of food including prepared foodstuffs which would not have required freezing in their unprepared state.

                   VACUUM-PACKING

        Vacuum-packing stores food in a vacuum environment, usually in an air-tight bag or bottle. The vacuum environment strips bacteria of oxygen needed for survival, thereby slowing spoiling. Vacuum-packing is commonly used for storing nuts to reduce the loss of flavor from oxidation.

                               SALTING

          Salting or curing draws moisture from the meat through a process of osmosis. Meat is cured with salt or sugar, or a combination of the two. Nitrates and nitrites are also often used to cure meat and contribute to the characteristic pink color, as well as inhibition of Clostridium botulinum.

                         SUGARING

          Sugar is used to preserve fruits, either in syrup with fruit such as apples, pears, peaches, apricots, plums, or in crystallized form where the preserved material is cooked in sugar to the point of crystallisation and the resultant product is then stored dry. This method is used for the skins of citrus fruit (candied peel), angelica, and ginger. A modification of this process produces glacé fruit such as glacé cherries where the fruit is preserved in sugar but is then extracted from the syrup and sold, the preservation being maintained by the sugar content of the fruit and the superficial coating of syrup. The use of sugar is often combined with alcohol for preservation of luxury products such as fruit in brandy or other spirits. These should not be confused with fruit flavored spirits such as cherry bright.

                         Smoking

         Smoking is used to lengthen the shelf life of perishable food items. This effect is achieved by exposing the food to smoke from burning plant materials such as wood. Most commonly subjected to this method of food preservation are meats and fish that have undergone curing. Fruits and vegetables like paprika, cheeses, spices, and ingredients for making drinks such as malt and tea leaves are also smoked, but mainly for cooking or flavoring them. It is one of the oldest food preservation methods, which probably arose after the development of cooking with fire.

Preservative food additives can be antimicrobial. These inhibit the growth of bacteria or fungi, including mold, or antioxidant, such as oxygen absorbers, which inhibit the oxidation of food constituents. Common antimicrobial preservatives include calcium propionate, sodium nitrate, sodium nitrite, sulfites (sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.), and disodium EDTA. Antioxidants include BHA and BHT. Other preservatives include formaldehyde (usually in solution), glutaraldehyde (kills insects), ethanol, and methylchloroisothiazolinone.

                        PICKLING

          Pickling is a method of preserving food in an edible anti-microbial liquid. Pickling can be broadly categorized into two categories: chemical pickling and fermentation pickling.

                             CANNING

          Canning involves cooking food, sealing it in sterile cans or jars, and boiling the containers to kill or weaken any remaining bacteria as a form of sterilization. Foods have varying degrees of natural protection against spoilage and may require that the final step occur in a pressure cooker. High-acid fruits like strawberries require no preservatives to can and only a short boiling cycle, whereas marginal fruits such as tomatoes require longer boiling and addition of other acidic elements. Low acid foods, such as vegetables and meats require pressure canning. Food preserved by canning or bottling is at immediate risk of spoilage once the can or bottle has been opened.

Preserved Food: Canning food is Food number of methods of prevention can be used that can either totally prevent, delay, or otherwise reduce food spoilage. Preservatives can expand the shelf life of food and can lengthen the time long enough for it to be harvested, processed, sold, and kept in the consumer’s home for a reasonable length of time.       

        EFFECT OF FOOD PRESERVATION

                 1. Effects on Children

          Children who are food insecure or come from families that are food insecure are more likely to require hospitalization and are at a higher risk of chronic health conditions like anemia and asthma. They also have frequent oral health problems.

        2. Food Insecurity Leads to Hunger  

            Hunger can also result from food insecurity. Hunger costs billions every year, with the US using about $178.9 billion every year. This makes the government spend more on feeding the nation, instead of concentrating such monies to other projects such as infrastructure, healthcare, and education.

             3. Increases in Food Prices

     Food insecurity means there is a shortage of food commodities, making the available food expensive to purchase. This means the prices will go up and will result in related items being more expensive. People’s access to food, care, feeding and access to healthcare may also become limited as a consequence, making the nation more insecure.

                   4. Unemployment

        When a nation is insecure about their availability of food, the economy will slow down. This means more people will lose their jobs, wages will be lost, and losses in income will be prevalent.

           5. A Rise in Health-related Costs

The higher the rate of food insecurity, the higher the risk of developing chronic illnesses such as heart diseases. The burden is, therefore, placed on the healthcare system. In a study, food-insecure households spent about $6,100 on medical care in a year as compared to $4,200 for food-secure households, which is a 45% increase in costs.

                    6. Violent Conflict

        Despite violence being a cause of food insecurity, the reverse is also true. Food insecurity, especially when caused by a rise in food prices, is a threat and results in violent conflict. It might not be the only cause, but coupled with other factors, for example, in the political or economic spheres, food insecurity could be the factor that determines whether and when violent conflicts erupt.

Food insecurity affects over 820 million people all over the world, and no region is exempt from it. Being a global challenge, governments and international institutions have employed all possible means to defeat food insecurity.

The United Nations, for instance, posed 17 Sustainable Development Goals, which ought to be achieved by 2030. Achieving food security, and improved nutrition, ending hunger and promoting sustainable agriculture is the second goal.

      SOLUTIONS OF FOOD PRESERVATION

               1. Reduce Food Waste

      Food is wasted mainly because of inefficient preparations, bumpy or bad roads, over-selective customers, and inadequate storage facilities. If storage facilities are improved and there are adequate preparations for how the food will be used, less food will be wasted, and there will be a more food secure community. As mentioned earlier, FAO reports that each year, the food wasted globally is about 1.3 billion tonnes.

         2. Reduce the Risk of Commercialising

          If food is grown for the purposes of feeding the community or nation, food insecurity levels will go down. Farmers can produce more food crops and will be able to produce cash crops when there are enough food crops in the market.

There will be less risk of commercialization of food if it is sufficient in the market. Governments should also implement programs that can allow farmers to know when there is sufficient food for everyone.

3. Improve Existing Infrastructural Programs

         Some farmers fail to get their produce to the market because of poor infrastructure including roads, storage facilities, and food processing equipment. It ends up rotting in the farms than being taken to those who need it or for processing. If the infrastructure is improved, more food will be available in the market and the food insecurity levels can go down.

               4. Improve Trade Policies

    Some farmers fail to feed the community because of unfair trade policies. Corporate giants have already stepped in and commercialized food, making it harder for small-scale farmers to have their products in the market. Governments should, therefore, improve such policies, and make it fair for everyone to participate.

            5. Promote Diversification

        Focusing on a single food crop or staple can produce terrible outcomes for food insecurity reduction. As such, to improve food security, there needs to be training on the importance of diversified and healthy diets for better nutrition.

With more varieties of food and an educated community on the importance of a diversified diet, there will be sufficient staple foods available in the markets.

                  6. Close the Yield Gap

         Most of our farming lands are drained of their natural fertility levels and cannot produce as much as they did years ago. To close the gap, governments and agricultural institutions in charge have come up with strategies and programs for improving crop yields, especially location-specific methods of sustainable agricultural intensification such as soil management and land improvement.

Land conversion should be avoided as it encroaches into natural habitats and forests, and affects biodiversity and wildlife, and increases GHG emissions. The strategy or program set up should ensure food is available for all, and that wildlife and forests are not affected.

7. Work Towards Defeating Climate Change

        Climate change is severely affecting our lives nd the production of food. If we fight climate change and farm sustainably, we will be able to ensure there is enough food for us and future generations. It is an additional step in fighting food insecurity.

            PRINCIPLE OF FOOD PRESERVATION

The basic principle of food preservation includes:

✓ Preservation or delay of microbial decomposition: That is archived by :

✓ Keeping out microorganisms (asepsis)

✓ Removal of microorganisms,i.e., by filtration

✓ Hindering the growth of activity of microorganisms,i.e., by low temperature, drying, anaerobic conditions, &

✓ Killing the microorganisms,i.e., by heat or radiations.

✓ Preservation or delay by self – decomposition of food. This is brought about by :

✓ Destruction or inactivation of food enzymes i.e, by blanching&

✓ Preservation or delay of chemical reactions i.e, preservation of oxidation by means of an antioxidant.

✓ Preservation of damage caused by insects, animals & mechanical causes.

          Importance of food preservation     

Food production and supply does not always tally with the demand or meets of the people. In some places there is surplus production of a food product, whereas in some other place there is inadequate supply. Even foods are perishable and semi-perishable like juicy fruits, vegetables, mangoes, tomato, papaya and many more, which very quickly gets spoilt. It is therefore important to improve and expand facilities for storage and preservation of food. Food preservation helps in:

1. Increasing the self-life of foods thus increasing the supply. So many perishable foods can be preserved for a long time.

2. Making the seasonal food available throughout the year.

3. Adding variety to the diet.

4. Saving time by reducing preparation time and energy, as the food has already been partially processed.

5. Stabilising prices of food, as there is less scope of shortage of supply to demand.

6. Decreasing wastage of food by preventing decay or spoilage of food.

7. Improving the nutrition of the population. Preserved foods help people to bring a variety in the diet, thereby decreasing nutritional inadequacies.