67D-12 |
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L. WANG1, Y. L. Xiong1, and J. Gomez-Basauri2. (1) Dept. of Animal Sciences, University of Kentucky, Lexington, KY 40546, (2) Alltech Inc., Nicholasville, KY 40356 Many proteins and protein hydrolysates have been shown to possess antioxidant activity in food model systems. In particular, an autolyzed yeast was reported in the 1970s to inhibit lipid oxidation. As new hydrolyzed yeasts or yeast extracts are increasingly produced as flavoring agents for food uses, research is needed to evaluate their potential antioxidant activity in food systems. Our objective was to determine the possible in situ antioxidant activity of two commercial yeast extracts in cooked beef patties. Fresh and homogenous salt-free ground beef was divided into five equal portions, one used for preparing control meat patties (without yeast extract) and four for treatment with yeast extracts A and B at levels of 0.1, 0.5, 1.0 or 1.5%. Thiobarbituric acid-reactive substances (TBARS) were measured in cooked patties during refrigerated storage (5°C) up to 7 days. The total antioxidant reducing capacity of both yeast extracts was also analyzed by the ferric reducing/antioxidant power (FRAP) assay. The yeast extracts suppressed (P < 0.05) TBARS formation in cooked beef patties during storage. The inhibition was enhanced with the level of yeast extract addition but no difference was seen between yeast extracts A and B. A 17-20% reduction in TBARS was observed with a 1.5% addition on beef patties stored for 7 days. FRAP values, not affected by NaCl, were higher as the concentration of yeast extracts increased, indicating a dose-dependent inhibitory activity by both yeast extracts. The antioxidant activity present in both yeast extracts evaluated indicates their potential of improving oxidative stability of foods, an added benefit to their main role as flavor enhancers.
Session 67D, Food Chemistry: Lipid and carbohydrate chemistry
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