酶解改性对燕麦粉中淀粉含量及消化性的影响

为研究酶解对燕麦粉的淀粉含量和消化性的影响,本文采用双波长法测定天然燕麦粉、焙烤燕麦粉、酶解燕麦粉中直链淀粉、支链淀粉及总淀粉含量,并测定其快速消化淀粉、慢速消化淀粉和抗性淀粉含量以评价其消化性,利用红外光谱仪及电镜对其结构和颗粒形貌进行分析。结果表明,与天然燕麦粉相比,焙烤燕麦粉中直链淀粉、支链淀粉及总淀粉含量没有显著变化(p>0.05),但酶解改性燕麦粉变化极显著(p<0.01),分别下降了77.97%、43.55%、46.19%;焙烤燕麦粉中快速消化淀粉、慢速消化淀粉和抗性淀粉含量没有显著变化(p>0.05),但酶解改性燕麦粉变化极显著(p<0.01),分别下降了82.29%、57.06%、33.48%;经淀粉的红外光谱及1047/1022、1022/995 cm^-1特征吸收比值没有显著变化(p>0.05)。经焙烤和酶解改性的燕麦粉中大淀粉颗粒表面出现较多的凹陷,而酶解改性后的淀粉中含有的小颗粒较少,且表面的凹陷程度不同。酶解改性极显著降低了燕麦粉的直链淀粉、支链淀粉、总淀粉、快速消化淀粉、慢速消化淀粉及抗性淀粉含量(p<0.01),会对燕麦粉加工性能及营养价值产生影响。

Effect of Enzymatic Modification on Starch Content and Digestibility of Oat Flour

To study the effect of enzymatic treatments on the starch content and digestibility of oat flour, the content of amylose, amylopectin and total starch in native oat flour, baked oat flour and enzymatic modified oat flour were determined by dual-wavelength spectrophotometry method, and the content of rapidly digestible starch, slowly digestible starch, resistant starch in different oat flour were determined to evaluate the digestibility of oat flour. The structure and particle morphology of oat flour were analyzed by infrared spectrometer and electron microscope. The results showed that, compared with the native oat flour, the content of amylose, amylopectin and total starch had no significant changes (p>0.05) in baked oat flour. But there were extremely significantly change (p<0.01) in enzymatic modified oat flour, which decreased by 77.97%, 43.55% and 46.19% respectively. The content of rapidly digestible starch, slowly digestible starch, resistant starch had no significant changes (p>0.05) in baked oat flour. But there were extremely significantly change (p<0.01) in enzymatic modified oat flour, which decreased by 82.29%、57.06% and 33.48% respectively. No significant differences (p>0.05) were observed in infrared spectrum and the ratio of characteristic absorbance at 1047/1022 cm-1 and 1022/995 cm-1. Large starch granules of baked and enzymatic modification oat flour showed more indentations. The starch by enzymatic modification exhibited a decrease in small granules and the degree of indentations was different. This study demonstrated that enzymatic treatments could cause extremely significant reduction in the content of amylase, amylopectin, total starch, rapidly digestible starch, slowly digestible starch and resistant starch in oat flour (p<0.01), which would result in changes in their physicochemical and digestibility properties.