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A knowledge of the factors that favor or inhibit the growth of the microorganisms is important in understanding the principles of food spoilage and preservation. Six major factors: 1. Moisture 2. Oxygen 3. Temperature 4. Acidity, pH 5. Nutrients 6. Growth inhibito
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1. Factors that influence microbial activity
16. pH ranges for major foods
Fruits : 3.0 – 4.5
Vegetables : 4.6 – 6.6
Meat : 5.5 – 6.8
Milk : 6.0 – 6.8
Pickling : Production of acids in foods by fermentation.
Acetic-, citric-, lactic-, propionic-, benzoic-, and sorbic acids added to foods for preservation (acidulants)
pH also affects resistance of microorganisms to destruction during heating, drying and other processes
20. Antibiotics used to control microbial growth Cell wall inhibitors
Protein synthesis inhibitors
DNA replication inhibitors