Comparing the effects of hydrothermal and microwave processes on the physicochemical properties of rice bran.

Today, bran is considered a functional compound in the food industry. The aim study was to investigate different processing methods of rice bran to improve its physicochemical characteristics. Treatments were prepared in 12 groups, control (C0), 4 samples hydrothermal treated H1 and H2 (1 and 2 h at 30 °C, respectively), H3 and H4 (1 and 2 h at 80 °C, respectively), 4 samples microwave treated M1 and M2 (4 and 7 min at a 600 w, respectively), M3 and M4 ((4 and 7 min at a 600 w, respectively), 4 samples hydrothermal -microwave treated HM1 and HM2 (First, 1 and 2 h at 50 °C, respectively, then 4 min at 750 w), HM3 and HM4 (First, 1 and 2 h at 50 °C, respectively, then 7 min at 750 w). The results showed that the hydrothermal - microwave method was more effective in reducing phytic acid than the other two methods (p<0.05) so the HM4 treatment had the lowest amount of phytic acid (p<0.05). The color value test showed the lowest ΔE change was related to rice bran hydrothermal treated (H1 with ΔE equal to 6.36) (p<0.05). The hydrothermal -microwave process showed the highest retention of iron, zinc, and calcium (p<0.05). Most minerals were shown in HM1 (6.68, 1.56, and 106.43 ppm, respectively). The heavy metals test indicated that in all treatments, the number of heavy metals significantly decreased compared to the control (p<0.05). However, the microwave method was more effective than others (p<0.05). Therefore, it can be concluded that using the hydrothermal -microwave method provides better quality rice bran. [ABSTRACT FROM AUTHOR]