MB 351 Lecture 70: 16.6 Food Microbiology
Document Summary
4:25 pm: most food we eat is non-sterile, history, beer, bread, cheese were all methods of preserving food, early methods, drying, adding salt and sugar, fermentation. Improperly doing this can lead to botulism: early laws, no eating blood sausage, made by putting blood into stomach of pig and smoking it. Supplied british army with canned meat: pasteur, discovered agents of putrefaction, created pasteurization, germ theory of disease. Lower water activity inhibits growth: water activity is measure of water use for metabolic processes, perishable is high water content, ph, affects chemical rxns. Lower temps prevent growth: perishable foods need to be frozen long term. Food spoilage: overgrowth of microbes in food, not necessarily dangerous, food pathogens cause issues. Salmonella: no taste or smell, toxins, ergotism toxic condition. Food preservation: growth of fungus in grains, filtration, changing ph, low temp, 4c retards but not stop, canning, heated and kills spoilage microbes, pasteurization, ruduces spoilage orgs.
