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The mild alkali extraction combined with the enzymatic hydrolysis was explored to extract protein from glutinous rice bran in the study, and the function properties of the proteins were investigated. The mild alkali extraction of pH 5.0 and temperature 50°C was carried out firstly for the water‐soluble protein extraction from the bran at the solid–liquid ratio of 1:10 (w/v) for 3.0 h, and the complex enzyme of cellulase and papain (7:3, w/w) were subsequently added to hydrolyze the residue for a better protein yield. After a mild proteolysis treatment under the conditions of enzyme addition 5.0%, pH 6.0, temperature 55°C and time 4.5 h, the final 90.2 ± 0.22% protein yield was obtained. It was interesting that the DPPH radical scavenging activity of the IC50 0.71 mg/ml was significantly improved, meanwhile, based on the combined extraction strategy, the protein solubility, emulsifying, and foaming properties were significantly enhanced in a wide range of pH environments. These results demonstrated that the mild alkali extraction combined with the enzymatic hydrolysis could be used in the glutinous rice bran protein extraction with high yield and good functionality, and the extracted protein could be potentially applied in food industry as nutraceutical ingredient or as the functional ingredient in the commercialized food products. Novelty impact statement: Although the glutinous rice bran has an abundance of protein content, the protein has not been well extracted yet to be utilized in the food industry. Therefore, the proper procedure needs to be explored for glutinous rice bran protein extraction. The mild alkali combined with the enzymatic hydrolysis was firstly applied in the study, and the protein yield of glutinous rice bran protein was notably improved, furthermore, the antioxidant and function properties of glutinous rice bran protein also have been significantly increased because of the mild extraction and proteolysis. [ABSTRACT FROM AUTHOR]

A simple and efficient method to extract and purify anthocyanins from black rice was developed in this work. After pretreatment of black rice, anthocyanins were extracted by buffer solutions, and were purified using membrane separation and resin adsorption. The single-factor experiments and orthogonal design were applied. The results showed that extraction ratio could be 0.99 ± 0.01% under the optimal condition of liquid-solid ratio 12:1, temperature 50C, time 80 min and pH 3.2. The 3 kDa molecular weight cut-off (MWCO) was used to remove proteins and polysaccharides, and the DM301 resin was found to have both good adsorptivity and desorptivity for anthocyanins. After the elution using 85% (vol/vol) ethanol solution, the purified anthocyanins were obtained by retention with the membrane of 200 Da MWCO. The recovery and purity of the anthocyanins finally obtained was 0.86% and 95.93%, respectively. The results are beneficial to the large-scale extraction of anthocyanins from black rice. Practical Applications Due to the growing demand for natural pigments, the natural anthocyanins have drawn great attentions. However, the immaturity of the large-scale purification procedures has limited the application of anthocyanins in functional food and pharmaceutical industries. Since the black rice is the rich source of anthocyanins, the large-scale water extraction and macroporous absorbent resins purification parameters were systematically investigated in the current study. About 0.86 g anthocyanins could be obtained from per 100 g black rice based on the large-scale method, which has a good recovery, and the purity could reach 95.93%. Meanwhile, the whole procedure was green and non-pollution as the primary solvents were water and ethanol. Furthermore, the results also would be conducive to the processing and utilization of black rice. [ABSTRACT FROM AUTHOR]