Food processing means manipulation of raw materials from plants or animals into food. Since agriculture and animal husbandrywere established postharvest procedures were necessary to preserve for a longer time the increasing food supplies coming from thefields and domesticated animals. Food is one of the best culture medium for a lot of microorganisms and preventing food spoilagecaused by enzymes and microorganisms is crucial. Deterioration of food is caused mainly by three natural processes:1. Oxidation – vegetables after harvesting or meat after animal slaughtering get in contact with the oxygen in the air that makesthem rancid and unpleasant.2. Enzyme action – all food contains natural enzymes that break down proteins, fats, and carbohydrates to their simple componentsuntil but food spoilage if left uncontrolled.3. Microbial action – all food can be attacked by bacteria and fungi that cause food spoilage and release toxic components.The first methods of food processing were based on some chemical procedures like adding salt to meat, sugar to fruit, reaching anacidic pH, storing in alcohol. High temperatures were also used to exsiccate food. The basic action of these procedures is the reductionof water activity (aw). The metabolism of all living cells is based on aqueous environment and all enzymes have reduced or noactivity in substrate in low water content. However, the original taste and several nutritional organoleptic characteristics are usuallylost with these procedures. Low-temperature conservation (refrigeration and freezing) prolonged fresh food properties but psychotropic(cold-resistant) organisms can be still dangerous i.e., Listeria monocytogenes and Yersinia enterocolitica.Microbiological safety of food remains a dynamic situation influenced by multiple factors and food safety standards depend onconstant monitoring and surveillance from farm to fork. Food is an excellent vehicle for well-recognized bacteria i.e., Salmonella,Campylobacter, and L. monocytogenes and virus such as norovirus, hepatitis A, rotaviruses. However, less prevalent pathogens andrare agents like prions and new alarming topics such as antimicrobial resistance in foodborne pathogens (Salmonella, Campylobacter,Shigella, methicillin-resistant Staphylococcus aureus, Escherichia coli) are relevant for policy-makers. Many parasites are also transmittedthrough food (i.e., Toxoplasma gondii, Cryptosporidium, and Trichinella) but effective monitoring is not performed for mostof them in foodstuff, livestock, and food process establishments. Additionally, some parasitic infection such as trichinellosis is oftentransmitted through the meat of game animals (Pozio, 2007).Other hazards such as chemical contaminants, toxins, and allergens are important in food-transmitted illness.
|Titolo della pubblicazione ospite||Reference Module in Food Sciences|
|Numero di pagine||9|
|Stato di pubblicazione||Published - 2015|