MIC 320 Lecture 4: Lecture 4
27 Oct 2016
School
Department
Course
Professor
Document Summary
Control by chemicals chapter 13: food preservatives. Benzoic acid: sodium benzoate was the first fda approved food preservative, inhibit molds, yeasts, and some bacteria, use in low acid foods such as ketchup, salsa, and fruit juice. Sorbic acid: inhibit molds, yeasts, and many bacteria (aerobic, catalase positive, low acid foods, cakes, meats, fermented dairy foods. Propionic acid: inhibit primarily molds, use in breads, cakes, some cheese. Mode of action: diffuse across cell membrane act as proton ionophores proton leakage into the cell weaken membrane potential lost membrane functions. Low ph, more disassociated molecule: the differential charge across the cell membrane creates membrane potential or the proton motive force (pmf). Pmf is required for transport, motility, respiration, etc. Sulfur dioxide (so2), sulfite (so3), bisulfite (-hso3), metabisulfite (s2o5: used in dried fruits, juice, molasses, etc, not permitted in meats or foods recognizable as sources of thiamine. Target organisms: inhibit molds, yeasts, and bacteria.
