Chapter 3: Microbial Food Spoilage (Spoilage Signs (Sliminess (e.g.…
Chapter 3: Microbial Food Spoilage
Undesirable deterioration of food quality that may result in changes in:
appearance of food.
Factors that affect spoilage:
Most bacteria, for example, do not grow at water activities below 0.91, and most molds cease to grow at water activities below 0.80.
Danger Zone Temperature (5-60 degree celsius)
Direct relation to environment.
e.g. environment storage.
e.g. Vapor-proof packaging that keeps oxygen out helps reduce oxidation problems.
Chemical Reactions (contact with metal)
Growth & multiplication of microorganisms
e.g. improper handlings.
Insects, Rodents, Birds
Non Microbial Spoilage
e.g adding spoon or fork during cooking.
e.g. banana matures, the color changes from green to yellow to brown to black. The change is caused by the enzymes (chemicals) in the banana.
ripening, softening, of other fruits such as apples, peaches and tomatoes
e.g. Meat. From red to dark bright green.
Production of acid.
Meat to souring - rare.
Sour milk - production of lactic acid.
e.g. Cucumber - sliminess.
Throw the sliminess part at above the below part still can consume.
*applicable to fruits and vegetables only.
Milk no sliminess.
Meats - spongy.
Swollen / bubbling packaged & cans.
Breakdown of proteins - putrefaction
e.g. rotten egg smell