Introduction
Food processing and preservation are two important processes that foodstuffs undergo before reaching consumers. Food processing improves the quality of foodstuffs for human consumption, while food preservation aims at removing microbes and prolonging shelf life of food. The processing and preservation methods vary from one foodstuff to another, depending on the expected shelf life, the nature of microbes in the food, the types of enzymes present, the nutritional value of food, and the hygienic conditions. In essence, food processing and preservation methods aim at improving the quality and safety of foodstuffs, as well as prolonging their shelf life. Poor processing techniques and/or deprived preservation methods of foodstuffs endanger human lives because microbes grow and release chemicals that are harmful to humans. In this view, companies that process food need to apply effective processing techniques and appropriate preservation methods in improving the safety of foodstuffs. Therefore, this course work examines the principles of preservation, packaging requirements, and expected shelf life of foodstuffs such as canned corn, packaged uncooked beef, frozen green peas, beef jerky, and pickled carrots.
Principles of Preservation
Canning or commercial pasteurization is a method that is applicable in preservation of different forms of foodstuffs. Canning involves processing food in a controlled temperature and packaging them in airtight containers or sealed packages. The principle of canning method is to destroy anaerobic microbes and create an unfavorable environment for aerobic microbes. A common anaerobic microbe that spoils food is Clostridium botulinum, a ubiquitous bacterium that is present in water, air, and soil. The spores of C. botulinum enter food and germinate into C. botulinum, which is a lethal microbe that causes spoilage of food by producing botulinum toxin, a neurotoxin. Regarding the creation of an unfavorable environment, some pathogens and microbes only thrive in aerobic conditions. In this view, pasteurization of food at the temperature of 1210C for a period of 15 minutes destroys anaerobic microbes or spores. Furthermore, sealing of canned corn at this temperature prevent entry of oxygen, which promote the survival of aerobic microbes and the entry of other microbes or pathogens.
The principle of preserving uncooked beef is by modifying the atmosphere of the meat. The aerobic microbes that are present in the air spoil uncooked meat. Hence, the modification atmosphere in packages entails the removal of air and replacement of the air with a desired mixture of oxygen and carbon dioxide. An appropriate mixture of oxygen and carbon dioxide preserves the color of meat and prevents the growth of microbes.
The principle applied in the preservation of frozen green peas is the creation of unfavorable temperature that prohibits the growth of microbes. At very low temperatures that are below -9.50C, the microbes do not grow. Low temperature prevents the growth of microbes because it inactivates enzymes and slows down biochemical processes. Moreover, low temperature freezes the water and reduces its availability to support the growth of microbes.
The principle of preserving beef jerky involves the removal of fats and dehydration of beef. Since it is impossible to dry fats, their removal allows beef to dry quite easily. To hasten the process of dehydrating meat, addition of salts has proved to be effective in preventing the growth of microbes during the process of drying. A lower water activity that is less than 0.6 inhibits the growth of microbes, slows down biochemical processes, and inactivates enzymatic functions.
The principle of preserving pickled carrots entails the use of salts or acids in creating an unfavorable environment for the growth of microbes. Fermentation of carrots in brine (salt solution) and vinegar produces alcohol and acids, which have antimicrobial properties. While brine and vinegar have antimicrobial properties, fermentation process yields alcohol and acids that enhance the preservation of pickled carrots. The pH of pickled carrots that is less than 6.0 is effective in preventing microbes from growing and spoiling the carrots.
Packaging Requirements
Shelf Life Expectations
Conclusion
Methods of processing and preserving different forms of foodstuffs determine their shelf life. Comparative examination of different methods of preserving foodstuffs shows that high temperatures, low temperatures, dehydration, modification of the atmosphere, drying, and low pH are common principles of preserving food. The common requirements of packaging materials are airtight, waterproof, uncreative, and durable. Canned products such as corn have the longest shelf life, while freshly packaged foodstuffs like uncooked meat have the shortest shelf life. Storage conditions such as refrigeration and aeration influences the quality and safety of preserved products.