MCB 3020 Chapter Notes - Chapter 42: Food Spoilage, Lactococcus Lactis, Listeria Monocytogenes
20 Feb 2017
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If primarily carbohydrate spoilage most likely will occur. High water activity foods e. g. tomatoes show spoilage by fungi failry quickly. Neutral or alkaline ph foods like meats, bacteria are predominant in spoilage and putrefaction. Cooking meat products presents a reducing environment for microbial growth: preferred environment bc of amino acids, peptides and growth factors, allows for growth of anaerobes like clostridia. Grinding meat can distribute microorganism and increase surface area leading to faster spoilage if stored improperly. Gram positive bacteria used to grow on citrus concentrates- now leads to them being pasteurized, filtered then concentrated by heating under vacuum. Vitamin c and flavors are added back to product before packaging. Ready to serve juice is also pasteurized even though some flavor is lost. Higher relative humidity leads to faster food spoilage, even at a low temperature. Drier foods being placed in moist environments causes moisture absorption on the food surface that promotes microbial growth.
