FOOD MICROBIOLOGY
MICROORGANISMS IN FOOD
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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No
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Yes because with a lower pH it is able to slow down the microbes
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No
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Yes, because a lower pH prevents microbes from growing
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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: -Most bacteria are neutrophiles and grow best at near-neutral pH (center curve). Acidophiles have optimal growth at pH values near 3 and alkaliphiles have optimal growth at pH values above 9. At the other end of the spectrum are alkaliphiles, microorganisms that grow best at pH between 8.0 and 10.5.
Detailed explanation-3: -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-4: -Moderate changes in pH modify the ionization of amino-acid functional groups and disrupt hydrogen bonding, which, in turn, promotes changes in the folding of the molecule, promoting denaturation and destroying activity. The optimum growth pH is the most favorable pH for the growth of an organism.