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Background: The water unextractable arabinoxylans (WUAX) contain beneficial phenolic compounds that can be used for food rather than for animal feed. The antioxidant activities of defatted rice bran obtained by xylanase-aided extraction is reported herein. The chemical and molecular characteristics of extracted fractions were investigated., Results: The WUAX hydrolysate precipitated by 0-60% ethanol (F60), 60-90% ethanol (F6090), and more than 90% ethanol (F90) had decreased molar masses with increasing ethanol concentration. The fractions of interest, F60 and F6090, contained 75% arabinoxylans with ferulic acid as the major bound phenolic acid, followed by p-coumaric acid. According to chemical-based antioxidant assays F60 and F6090 exhibited higher diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric iron reducing ability than F90 which contained minor contents of small sugars and free phenolic acids. In cell-based antioxidant assays, using the fluorescent 2',7'-dichlorofluorescein diacetate probe, all three fractions were potent intracellular scavengers., Conclusion: The high molar mass of WUAX hydrolysates with high amount of bound phenolics contributes to the chemical-based antioxidant activity. All fractions of WUAX hydrolysates showed high potent intracellular scavenging activity regardless of molar mass, content and the component of bound phenolics. © 2017 Society of Chemical Industry., (© 2017 Society of Chemical Industry.)

In Job's tear, the germ is enfolded inside the kernel and comprises ca. one third of the whole grain. To assess the effect of germ on flour properties, degermed flour was manually prepared from grains of white and black husk cultivars. The protein of whole grain and degermed flours was not ignificantly different (p > 0.05). The antioxidant properties, which were total phenolic content, DPPH radical scavenging and reducing power, and coixenolide of whole grain and degermed flours of both cultiva·s were in the ranges of 7.33-8.18 mgGAE/g, 5.40-7.53%, 2.56-2.88 and 0.02-0.53 pglg, respectively. The Job's tear sta·ch granules showed a round and polyglonal shape and their average size was 11.68-12.29 pm. The gelatinization temperature range of white and black Job's tear starch was 67-8l"C and the retrogradation behavior of Job's tear starch occurred after storage at 4"C for 39 days as monitored by differential scanning calorimetry. The peak viscosity of the white Job's tear flours was greater than those of the black cultivar flours but the setback and pasting temperature was lower. The swelling power of the white Job's tear flours was higher than that of the black cultivar flours, but their solubility was lower and the opposite result was found in the starch. [ABSTRACT FROM AUTHOR]