Both yeasts and molds cause various degrees of deterioration and decomposition of foods. They can invade and grow on
virtually any type of food at any time; they invade crops such as grains, nuts, beans, and fruits in fields before harvesting
and during storage. They also grow on processed foods and food mixtures. Their detectability in or on foods depends on
food type, organisms involved, and degree of invasion; the contaminated food may be slightly blemished, severely
blemished, or completely decomposed, with the actual growth manifested by rot spots of various sizes and colors,
unsightly scabs, slime, white cottony mycelium, or highly colored sporulating mold. Abnormal flavors and odors may
also be produced. Occasionally, a food appears mold-free but is found upon mycological examination to be
contaminated. Contamination of foods by yeasts and molds can result in substantial economic losses to producer,
processor, and consumer.