MICR-4070 Lecture Notes - Lecture 18: Germination, Acetic Acid, Sodium Nitrite
23 Mar 2018
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Document Summary
Micr 4070: food and dairy microbiology: test 2 (lecture 9, heat treatments and preservation by. Microwave heat treatment: microwave energy (500 mhz to 10 ghz) Commercial microwaves have much less energy applied: internal heat generation caused by intermolecular friction. The water inside will behavior like a dipole: low cost but thermal non-uniformity. The water friction create high heat that is not uniform because it is dependent on where water molecules are located. Ohmic heating (toaster oven: also called direct electrical heating, thermal effect on microorganisms. Food antimicrobial agents are chemical compounds added or present in foods: benzoic acid is found naturally in cranberries and prunes. Most only are bacteriostatic or fungistatic and not bactericides or fungicidal: this means that they inhibit growth of these microbes and do not completely kill them. Cellular targets include the cell wall, cell membrane, metabolic enzymes, protein synthesis, and genetic systems.
