焙烤处理对发芽糙米生理活性物质及抗氧化活性的影响

Effect of Baking Treatment on Physiological Active Substances and Antioxidant Activity of Germinated Brown Rice

为探究焙烤处理对发芽糙米生理活性物质及抗氧化活性的影响,为开发焙烤类发芽糙米产品提供理论依据,以发芽糙米为研究对象,研究焙烤温度(125～175℃)和焙烤时间(15～30 min)对发芽糙米中γ-氨基丁酸、植酸、谷维素、抗氧化物质及抗氧化活性的影响。结果表明,150℃焙烤后的发芽糙米与其它温度相比,γ-氨基丁酸(GABA)损失率最小,植酸降解率与谷维素增加量较大,抗氧化物质与抗氧化活性下降较小;随着焙烤时间的增长,发芽糙米中的生理活性物质均呈不同程度的下降趋势,抗氧化物质及抗氧化活性显著下降(p<0.05),其中,焙烤15 min时,发芽糙米中GABA损失了5.58%,植酸降解率为43.53%,谷维素含量增加了21.54%;游离酚、结合酚和黄酮的下降程度分别为16.77%、18.54%和20.30%;在抗氧化活性方面,DPPH自由基清除率、ABTS清除率、FRAP值和ORAC值分别下降了14.77%、13.60%、9.10%和19.86%。因此,150℃焙烤15 min能最大限度地保持发芽糙米的生理活性物质和抗氧化活性。

In order to explore the effect of baking treatment on the physiological active substances and antioxidant activities of germinated brown rice,to provide a theoretical basis for the development of baked germinated brown rice products,the germinated brown rice was taken as the research object,and the effects of baking temperature(125~175℃)and time(15~30 min)on the content of physiological active substances in germinated brown rice were studied,includingγ-aminobutyric acid,phytic acid,oryzanol and antioxidative activity.The results showed that,the germinated brown rice after baking at 150℃had the lower GABA loss rate and more phytic acid degradation rate and oryzanol increments compared with other temperatures.With the increase of baking time,the physiological active substances in germinated brown rice showed a downward trend in varying degrees,and the antioxidant substances and antioxidant activities decreased significantly(p<0.05).After 15 min baking,GABA loss in germinated brown rice was 5.58%,phytate degradation rate was 43.53%,oryzanol content was increased by 21.54%,and the degree of decline of free phenols,bound phenols and flavonoids were 16.77%,18.54%and 20.30%,respectively.In terms of antioxidant activity,the DPPH radical scavenging rate,ABTS clearance rate,FRAP value,and ORAC value decreased by 14.77%,13.60%,9.10%and 19.86%,respectively.Therefore,15 min baking at 150℃could maintain the physiological active substances and antioxidant activity of germinated brown rice to the utmost.