Irradiation effect on lipid oxidation index on okara-based soybean flour

Abstract

Seasoned flour, also known as “farofa”, is a low cost industrialized product easy to prepare, which may be enriched with nutrients in order to improve its nutritional value. Typically, it’s made from maize or yuca tem-pered flour. However, soy seasoned flour (SSF), which is made from okara (inert-flavored-mass obtained as a residue from the soybean extract), is a viable alternative for nutritional enrichment in relation to the previous conventional tempered flour. This work aimed to reuse a by-product of processing of soybean okara to elaborate soy-seasoned flour and to analyze the possible effect of gamma irradiation at doses of 1 and 3 kGy, in the analy-sis of determination of lipid peroxidation. The preparation of SSF containing okara, dehydrated condiments and flavor uplifting proceeded at FATEC Marília. SSF samples were processed at “Centro de Energia Nuclear na Agricultura” (CENA), University of Piracicaba-SP, and irradiated with doses of 1 and 3 kGy in 60Co source. The dose rate was 0.269/h. Analysis were performed to determine the peroxide index of control samples and irra-diated in triplicate at 1, 15, 30 and 45 storage days according to the methodology for oils and fats with modifica-tions. Using this peroxide methodology, it was not detected changes in oxidative quality in the samples, whatever was the storage period. The flour having as a parameter 29.92% of lipids. We conclude that this product have excellent nutritional attributes regards to the conventional flour, though we must apply a different methodology to detect any radiation damage on lipid compounds using doses up to 3kGy.