Microorganisms, both bacteria and fungi, are used as additives in meats. milk, cereals, vegetables and fruits to produce fermented products. The fermented foods differ from the starting material in texture, flavor and keeping quality. Fermentation causes changes in the nutritional content of foods; vitamin and amino acid levels may increase, decrease or remain static, depending on the type of microorganism used and the product fermented. Microorganisms also impart desirable flavors, improve texture and enhance digestibility of foods. Fermentation destroys food spoilage organisms and permits preservation of food. Lactobacilli in cultured milks are used to supplement the normal intestinal flora in individuals suffering from digestive ailments or enteric diseases. Cultured milks are tolerated by lactose-intolerant individuals because of lactose utilization in the gastrointestinal tract by ingested lactobacilli. If sufficient acid is formed, foods which have undergone a lactic acid fermentation, such as fermented sausages or cheese. do not support growth of food poisoning microorganisms. Products which undergo controlled commercial fungal fermentations have been shown not to contain mycotoxins. Histamines and other biogenic amines are present in cheese and other fermented products. Fermentation offers a means of producing safe, nutritious foods with desirable organoleptic qualities and extended storage stability.
1Agricultural Research, Science and Education Administration, U.S. Department of Agriculture.