FOOD MICROBIOLOGY
MICROORGANISMS IN FOOD
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Low pH kills the microbes.
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Low pH slows down the microbes.
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Low pH prevents the microbes from growing.
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Low pH prevents the microbes from breathing.
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Detailed explanation-1: -Microorganisms, including yeasts, molds, and bacteria, are sensitive to a food’s pH. Very low or very high pH values will prevent microbial growth. As a practical matter, no unprocessed food has a pH value high enough to offer much preservative value.
Detailed explanation-2: -The butyric anaerobes, as these three Clostridium species causing spoilage in low-acid canned foods, are usually associated with spoilage of products with pH values between 3.9 and 4.5 producing blown cans and a butyric odor (Hersom & Hulland, 1980).
Detailed explanation-3: -Extremes of pH prevent microbial attack. Around neutrality, bacterial spoilage is more likely, with reports of Pseudomonads and Gram-negative bacteria growing in antacid mixtures, flavoured mouthwashes and in distilled or demineralised water. Above pH 8 (e.g. with soap-based emulsions) spoilage is rare.