The effect of replacing the isolated soy protein and temperature frying on reduction of donuts oil absorption

The aim of this study was to investigate the effect of frying temperature and replacement of soybean protein isolate (SPI) with wheat flour on chemical characteristics doughnuts. For this purpose samples doughnuts formulated replacement 3 and 7 percent SPI with wheat flour null and then fried at temperatures 150, 165 and 180 °C. Parameters moisture content, fat content, acid value, peroxide value and sensory properties were investigated. Statistical analysis was performed using a completely randomized factorial design. Means were compared using Duncan's test (p≤0.05) with each other. The results shown that, with increasing temperature and percentage replacement of wheat flour with SPI led to increasing moisture content and the oil content decreased in samples were doughnuts. Temperature increases from 150 ° C to 180 ° C in the process frying doughnuts Samples prepared with wheat flour, 3% and 7% SPI led to Increasing acid value oil absorbed in their 0.66, 0.64, 0.51 unit, respectively. Results of variance analysis showed significant effect type flour on the amount of hydroperoxides on oil is absorbed on case of donuts (p≤0.05). The results of the comparison means showed not follow the effect of the specific. The raters doughnuts Samples no significant difference in terms of our sensory evaluation (p≤0.05).