Dried tomato pomace, a byproduct of tomato processing, is an excellent source of α-tocopherol (vitamin E), which is used as an antioxidant in broiler meat. In a feeding study, there were no significant differences in body weight and feed per gain in chicks given diets with or without tomato pomace. Tomato pomace could be used as a source of α α α α α-tocopherol in broiler diets to decrease lipid oxidation (fat deterioration) during heating and long-term frozen storage of dark meat, and to prolong shelf life. Because tomato byproducts contain high levels of unsaturated fatty acids, the pomace must be defatted without losing vitamin E to minimize its oxidation potential. Although we found no evidence that introducing a high-fiber feed ingredient significantly limited broiler growth, more research is needed to enhance its practical applications.
IN2001, California farmers grew about 258,000 acres of processing tomatoes (USDA-NASS 2002), which are made into juice and concentrated products such as catsup, salsa, paste, puree, soups and sauces. About 10% to 30% of the raw tomato weight becomes waste, part of which is hauled fresh to nearby cattle and dairy farms and sold for a token fee. Tomato waste (pomace) consists of peels, cores, culls, seeds, trimmings, liquor and unprocessed green tomatoes picked by harvest machinery.The composition of tomato pomace varies according to agricultural and processing practices, the degree of drying, moisture removal and separation of cellulose. Tomato pomace can contain up to 25% high-lysine protein and 242 parts per million (ppm) of α-tocopherol (vitamin E). Tomato pomace is recommended for cattle and dairy cow feed due to the ability of these animals to digest fiber. Likewise, tomato seeds are recommended as a source of protein isolate in food applications for humans (Kononko et al. 1986;Cantarelli et al. 1989). However, the high temperatures used to process tomatoes may affect protein extractability (Canella and Castriotta 1980).
RESEARCH ARTICLE ▲ ▲Depending on the processing method, pomace can contain more than 31% fiber. Because high-fiber pomace (31%) is not easily digested by broilers and can dilute the available energy content of the feed, it has been used at less than 5% in the diets of these meat-type chickens. Because laying hens need less protein and are able to digest fiber, the potential use of tomato pomace in their feed is estimated as high as 15% (A. Mireles, Nutritionist/Feed Research Manager, Foster Farms, Livingston, Calif., personal communication).The levels of α-tocopherol in tomato pomace may be particularly useful in feeds for meat animals. Tocopherols, especially the alpha (α) form, help prevent lipid oxidation (deterioration of fats). They preserve the quality of heated or stored meat by reducing the end products of oxidation that cause discoloration, off odors and off flavors. Also, some byproducts of lipid oxidation may be hazardous to human health.Because the California broiler industry had a total value of about $472 million in 1997 and results fro...
