29B-25 |
Inhibition of lipid oxidation and stability of food system by emulsions and cryoprotectants |
Y. PARK, S. Keheller, D. J. McClements, and E. A. Decker. Dept. of Food Science, Univ. of Massachusetts, Amherst, Chenoweth Lab., Box 31410, Amherst, MA 01003-1410 Omega 3 fatty acids have considerable health benefits in atherosclerosis, blood clotting, and anti-inflammatory activity. Surimi is a highly functional concentrate of the myofibrillar protein of fish muscle that contains very little fat. The addition of emulsions containing w-3 fatty acid to surimi could provide a useful functional food if oxidative deterioration can be controlled. The aim of this research is to understand the factors influencing lipid oxidation in surimi containing oils high in w-3 fatty acid. The effect of cryoprotectants on lipid oxidation in w-3 fatty acid containing surimi was also investigated. Oil-in-water emulsion containing 30 % algae oil and 3 % whey protein isolate (WPI) was prepared with/without EDTA by homogenization. Emulsion (12.8g) was added to surimi (237.2g) to provide 500 mg of w-3 fatty acids per serving of surimi (85g). Bulk oil was added directly to surimi to compare differences with surimi containing emulsion. Color measurements were made with a Hunterlab Labscan II. Gel-forming ability was assessed by a torsion test. Determination of lipid oxidation products was made by measuring lipid hydroperoxide and thiobarbiturc acid reactive substances. Addition of the emulsion had no effect on gel strength while bulk oil decreased gel strength an average of 31%. All surimi treatmemts containing algal oil increased in Hunter a* and b* values due to the presence of carotenoids in the oil. LOOH and TBARS values were lower in surimi containing bulk oil compared to surimi with emulsified oil. Addition of EDTA and antioxidant [tocopherol isomers (1000 ppm), ascorbyl palmitate (500 ppm) and rosemary extract (1000 ppm)] to the WPI stabilized emulsion decreased lipid oxidation in surimi. STPP was the major surimi additive responsible for retarding the formation of LOOH and TBARS. This information can be used for preparing shelf-stable surimi that contains nutritionally beneficial w-3 fatty acids.
Session 29B, Food Chemistry: Lipids, antioxidants and emulsifiers
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