超声-微波协同提取富硒米糠蛋白的工艺优化及其抗氧化活性评价

Optimization of ultrasonic-microwave assisted extraction of selenium-enriched rice bran protein and evaluation of its antioxidant activity

为解决富硒米糠蛋白提取率低、提取时间长及提取后功能特性下降等问题,以脱脂富硒米糠粉为原料,通过单因素试验和正交试验对超声-微波协同提取富硒米糠蛋白的工艺进行优化,通过与超声辅助法、微波辅助法和碱提法比较,探究该提取方法对富硒米糠蛋白的提取效果、抗氧化活性以及提取后米糠颗粒表面形貌变化的影响。结果表明,超声-微波协同提取富硒米糠蛋白的最佳工艺条件为超声功率600 W、微波功率500 W、提取时间20 min、料液比1∶40,在此条件下富硒米糠蛋白的提取率为86.94%,与超声辅助法、微波辅助法、碱提法相比富硒米糠蛋白提取率分别提高了40.96%、48.00%、53.50%,并且提取的富硒米糠蛋白抗氧化能力和硒含量更高。扫描电镜结果显示,超声-微波协同提取后米糠颗粒表面疏松卷曲,完整皮层结构消失,说明超声-微波协同能通过强烈破坏米糠颗粒结构增加富硒米糠蛋白的提取率,并提高其抗氧化活性。综上,超声-微波协同提取技术能够促进富硒米糠蛋白的提取并提高其抗氧化活性。

In order to solve the problems of low extraction rate, long extraction time and decreasing functional properties of selenium-enriched rice bran protein(Se-RBP) after extraction, using defatted selenium-enriched rice bran powder as raw material, the process of ultrasonic-microwave assisted extraction(UMAE) of Se-RBP was optimized through single factor experiment and orthogonal experiment, and the extraction effect, antioxidant activity of Se-RBP extracted by UMAE and surface morphology changes of rice bran particles after UMAE were compared with ultrasonic-assisted extraction(UAE), microwave-assisted extraction(MAE) and alkali-assisted extraction(AAE). The results showed that the optimal conditions of UMAE was ultrasonic power 600 W, microwave power 500 W, extraction time 20 min and material liquid ratio 1∶40. Under these conditions, the extraction rate of Se-RBP was 86.94%, which increased by 40.96%, 48.00% and 53.50% compared with UAE, MAE and AAE, respectively, and the antioxidant capacity and selenium content of the extracted Se-RBP were higher. The results of scanning electron microscopy showed that the surface of rice bran particles after UMAE was loosened and curled, and the intact cortex structure disappeared, indicating that UMAE could increase the extraction rate of Se-RBP by strongly destroying the structure of rice bran particles, and improve its antioxidant activity. The UMAE technology can promote the extraction of Se-RBP and improve its antioxidant activity.