Research Note: Ethoxyquin and Ethylenediaminetetraacetic Acid for the Prevention of Rancidity in Rice Bran Stored at Elevated Temperature and Humidity for Various Lengths of Time

Abstract

The susceptibility of rice bran to oxidative rancidity during storage and the detrimental effects of rancid rice bran on broiler performance have been documented. The addition of antioxidant or metal chelator or both would be a plausible approach in preserving the nutritive quality of stored rice bran. Ethoxyquin and EDTA were each added at levels of 0, 250, 500, or 1,000 parts per million (ppm) in a factorial arrangement to 1-kg aliquots of fresh rice bran and maintained at 35 to 38 C with 80 to 90% relative humidity for 4 wk. Samples were taken at 7-day intervals and placed in a freezer (–30 C) before the fat was extracted. Fats were analyzed for peroxide values using the initial peroxide value (IPV) and 20-h active oxygen method (AOM). The addition of 250 ppm ethoxyquin proved effective in significantly (P<.05) reducing the IPV but not the 20-h AOM peroxide level. In contrast, 1,000 ppm EDTA significantly (P<.05) lowered the 20-h AOM value. Therefore, rancidity development in stored rice bran can be slowed by the addition of ethoxyquin or EDTA or both.