By-Products of Tomato Processing as a Source of Functional Compounds

Abstract

By-products of tomato processing represent a major disposal problem for the industry concerned. The exploitation of by-products of tomato processing as a source of functional compounds and their application in food is a promising field considering that with the food market the innovative secter of functional foods is growing fast and becoming more important.Tomato seed contained the highest values of protein(28.03%), and ether extract(20.83%), while tomato skin had the high value of crude fiber (55.42%) ,and ash (3.86%). Tomato seed meal contained avaliable amount of alkaloids, total phenolic, saponin, while tomato skins had the high content of carotenoids and lycopene. These substances had an antioxidants or anticancer effect. So, the presence of these compounds in tomato wastes allow their application in food processing to obtain healthy products. Physical and chemical properties of tomato seed oil indicated that oil had 0.923 specific gravity, 1.478 refractive index, 114.165 iodine value, 90.476 peroxide value and 3.685 free fatty acids.The results reveled that tomato seed oil contained 79.99% unsaturated fatty acids. Linoleic acid (18:2 ω6) is the major fatty acids was in a concentration of 56.67% followed by oleic acid (18:1 ω9) 18.37%. Results indicate that tomato seed contained higher levels of some essential amino acids i.e. phenylalanine, leucine, isoleucine and lysine than those by FAO/WHO (1993). Lysine was found to be the first limiting amino acid, while phenylalanine was the second limiting amino acid in the defatted tomato seed and skin meal. So,tomato seeds were good source for most essential amino acids such as phenylalanine, leucine, isoleucine and lysine which were higher than those given in FAO/WHO.