CSpoilage of Fruit Juices

The lactobacilli are important in the spoilage of fruit juices. Some strains are quite acid tolerant and can metabolize citric and malic acid. This reduces the acidity and results in a bland, rather flat flavor and a loss in astringency. A buttermilk flavor results in the fruit juice. (2) Slimy consistency. Bacteria of the species Leuconostoc mesenteroides produces a slimy, unpleasant consistency of fruit juices. (3) Fermentation. Yeasts contaminate and ferment...

Definitions

Before any serious discussion of food deterioration, we need to define several terms that are important in understanding food deterioration. a. Food Deterioration. The first term is food deterioration. We define this term as a series of continuous degradative changes occurring in a food item which may affect the product's wholesomeness, result in a reduction of its quality, and or alter its serviceability. (1) Deterioration is a continuing process that begins the moment an animal is slaughtered...

Enzymatic Degradation

Deterioration of foods resulting from the catalytic action of enzymes is easy to observe. (1) An example is the ripening process of the banana wherein it becomes sweeter, softer, less astringent in taste, and more odorous. One of the reactions in this process is the hydrolysis (degradation) of the starch (essentially tasteless and insoluble in the water of the banana) to simple water-soluble sugars. (2) Another example is the overripe tomato. Here the softening is...

Mechanical Damage Of Fresh Fruits And Vegetables

Mechanical damage is due to the action of machinery, mishandling, and or improper packaging, and may result in cuts, punctures, bruises, and or abrasions. The fleshy fruits are very susceptible to mechanical damage. Product texture may be soft around any cut, puncture, or abrasion. Both internal and external examination of the product may be necessary to determine the extent of mechanical damage. b. Darkening in Color. The following color change may indicate mechanical damage a...

Microbial Spoilage

From the moment fish are taken from the water, a series of deteriorative changes start to occur which eventually will render the fish unmarketable. Since these changes occur relatively rapidly, fish are probably the most perishable of all flesh foods. Microbiological action produces the most extensive of the deteriorative changes. b. Product Examination by the Inspector. Examine the product and note abnormal color s , odor s , and or texture s typical of...

Discolorationdarkening

Examine the product for discoloration darkening. b. Sources of Discoloration. Discoloration darkening may be due to hydrolysis reactions, surface evaporation, or microbial spoilage. c. Other Sources. The inspector may find other deteriorative conditions such as dehydration or microbial spoilage in determining discoloration in meat and meat products. d. Surface Discolorations. The following surface discolorations may be observed in meat and meat products. 1 Browning. A brownish...

Nonenzymatic Browning

Nonenzymatic browning is a process in which foods darken without the catalytic effect of enzymes. It differs markedly from the darkening of fresh fruits and vegetables due to enzymatic degradation. The food constituents responsible are certain simple sugars which react with proteins, amino acids, or other substances normally present in the foods. b. Flavor Change in Some Foods. Although the darkening in color of the food may be undesirable, the more notable changes are...