Spoilage

Preservatives. Without control of yeasts (qv), molds, and bacteria, the food industry would experience considerable economic losses each year owing to spoilage. Sugar, salt, and wood smoke have been used for centuries to preserve food. These methods, however, are not compatible with all food products thus preservatives, also known as antimicrobials, are used. 

The color of red meat depends on oxygen. The color of the meat pigment myoglobin is purple. The bright red color of the fresh-as-cut meat is from oxymyoglobin. To preserve red meat, the objectives are to retard spoilage and weight loss, and to deUver red color at the consumer level. 

Produce. Eresh fmits and vegetables must be handled gendy because of sensitive stmctures and the ubiquitous presence of microorganisms. Damage to the product surfaces provide channels through which microorganisms can enter to initiate spoilage. 

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Seed Treatment, prevent spoilage, premature germination, sprout growth... 

Propyl alcohol [71-23-8J, 1-propanol, CH2CH2CH2OH, mol wt 60.09, is a clear, colorless liquid having a typical alcohol odor it is miscible ia water, ethyl ether, and alcohols. 1-Propanol occurs ia nature ia fusel oils and forms from fermentation and spoilage of vegetable matter (1). 

Candy is coated with shellac to seal in moisture and keep the product fresh. The coating provides a high gloss to the confection, which improves its appearance. Citms fmits and some apples are often coated with shellac. This improves the appearance, while allowing the fmit to breathe without spoilage. Shellac is used as a stiffener for felt hat bodies, primarily for recreational hats. It is also used to stiffen playing cards, providing "snap."... 

Salt preserves foods by providing a hostile environment for certain microorganisms. Within foods, salt brine dehydrates bacterial cells, alters osmotic pressure, and inhibits bacterial growth and subsequent spoilage. Dry salt and salt brine are used in several types of curing processes. Pickles are preserved in strong brine before final processing. 

Food apphcations of sorbates expanded rapidly after issuance of the original patents in 1945 (92). The first uses were based on their excellent fungistatic properties and thus involved foods with low pH and/or low water activity in which yeasts and molds are the primary spoilage agents. More recent appHcation research has been directed toward utilizing the bacteriostatic properties of sorbates. 

Sorbate combined with mild heat has a synergistic effect with regard to microbial destmction thus, in the presence of 0.025—0.06 wt % sorbate, products such as apple juice, peach and banana sHces, fmit salads, and strawberries can be treated with less severe heat treatments to extend shelf life (119,120). Sorbates increase the heat sensitivity of various spoilage fungi under varying conditions of pH and water activity (121—124). A similar synergistic effect has been reported for the combination of sorbate with irradiation (125). 

Sucrose is often used as a decorative agent to impart a pleasing appearance to baked goods and confections (36). In jams and jeUies, sugar raises osmotic pressure and lowers water activity to prevent spoilage (18). Sucrose is a fermentation substrate for lactic acid in cultured buttermilk (40) and lowers the freezing point of ice cream and other frozen desserts to improve product mouthfeel and texture. 

Sucrose monoesters (SMEs) are used as nonionic surfactants, in detergents and as emulsifiers in foods. Some SMEs have bacteriostatic activity and are used to prevent spoilage in beverages. Semperfresh, an SME produced in the U.K., is used as a coating to extend the shelf life of fmits and vegetables (21,29). 

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