30A-5 |
Investigation of an egg albumen coating as a courier of antioxidants in the prevention of lipid oxidation and rancidity in poultry products |
D. B. ARMITAGE and N. S. Hettiarachchy. Dept. of Food Science, Univ. of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704 With suitable plasticizers, aqueous solutions of egg albumen form films with good mechanical properties. Protein films may be functionalized by the addition of antioxidants or antimicrobial compounds. It is postulated that addition of antioxidant compounds to a protein film will result in increased poultry shelf life. The effectiveness of synthetic antioxidants in the prevention of rancidity has been previously demonstrated. This investigation demonstrates the effectiveness of natural antioxidants in the extension of poultry shelf life when applied as a protein film additive. Analysis of soybean oil with antioxidant addition using an Oxidative Stability Instrument demonstrated the activity of natural antioxidants investigated by extending oxidation times by 50% or more. Film solutions were prepared containing the natural antioxidants Vitamin E, Rosemary Extract, and Fenugreek Extract in concentrations ranging from 1000 to 3000 ppm. For the experiment control solutions of deionized water, plasticizer and protein were prepared. Raw chicken breast meat was cubed into 3/4" pieces and treated with the solutions. One set was boiled for 10 minutes in the film solutions with and without antioxidant to prepare cooked product. The second set was treated by vacuum marination to prepare raw product. Samples were stored at 5 (C, -5 (C and freeze dried and stored at -5 (C and monitored for lipid oxidation using the Thiobarbituric Acid test. Analysis showed oxidation inhibition by antioxidant addition in comparison to control treatments in refrigerated samples by 30% or more, with Vitamin E showing the highest inhibition in cooked samples and fenugreek extract showing the highest inhibition in raw samples. Proteolysis of refrigerated samples as evidenced by putrescence and odor renders them too poor to evaluate after 7-10 days. In frozen and freeze dried storage, little or no oxidation was observed over a six month period in any of the preparations. The antioxidant coating approach is likely to be effective in extending refrigerated storage if combined with methods of proteolysis inhibition.
Session 30A, Food Chemistry: Lipids
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