Chusak Charoonsri, Henry Christiani Jeyakumar, Chantarasinlapin Praew, Techasukthavorn Varanya, Adisakwattana Sirichai
Department of Nutrition and Dietetics, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
Clinical Nutrition Research Centre, Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research, Singapore 117599, Singapore.
Foods. 2018 Jul 2;7(7):102. doi: 10.3390/foods7070102.
This study aimed to assess the effect of the L. flower extract (CTE), on the inhibition of pancreatic α-amylase, in vitro starch hydrolysis, and predicted the glycemic index of different type of flours including potato, cassava, rice, corn, wheat, and glutinous rice flour. The application in a bakery product prepared from flour and CTE was also determined. The results demonstrated that the 1% and 2% (w/v) CTE inhibited the pancreatic α-amylase activity by using all flours as a substrate. Moreover, 0.5%, 1%, and 2% (w/v) CTE showed a significant reduction in the glucose release, hydrolysis index (HI), and predicted glycemic index (pGI) of flour. In glutinous rice flour, 1% and 2% (w/v) CTE had a significantly lower level of rapidly digestible starch (RDS) and slowly digestible starch (SDS) with a concomitant higher level of undigested starch. The statistical analysis demonstrated strong positive significant correlations between the percentage of CTE and the undigested starch of wheat and cassava. The addition of 5%, 10%, and 20% (w/w) CTE significantly reduced the rate of starch digestion of the wheat bread. The pGI of bread incorporated with 5% CTE (w/w) was significantly lower than that of the control bread. Our findings suggest that CTE could reduce the starch digestibility, the HI, and pGI of flour through the inhibition of carbohydrate digestive enzymes. Taken together, CTE may be a potent ingredient for the reduced glycemic index of flours.
本研究旨在评估L. flower提取物（CTE）对胰腺α-淀粉酶的抑制作用、体外淀粉水解情况，并预测不同类型面粉（包括马铃薯、木薯、大米、玉米、小麦和糯米粉）的血糖生成指数。还测定了CTE在由面粉制备的烘焙产品中的应用。结果表明，以所有面粉为底物时，1%和2%（w/v）的CTE抑制了胰腺α-淀粉酶的活性。此外，0.5%、1%和2%（w/v）的CTE使面粉的葡萄糖释放量、水解指数（HI）和预测血糖生成指数（pGI）显著降低。在糯米粉中，1%和2%（w/v）的CTE使快速消化淀粉（RDS）和缓慢消化淀粉（SDS）水平显著降低，同时未消化淀粉水平升高。统计分析表明，CTE的百分比与小麦和木薯的未消化淀粉之间存在强正显著相关性。添加5%、10%和20%（w/w）的CTE显著降低了小麦面包的淀粉消化率。添加5% CTE（w/w）的面包的pGI显著低于对照面包。我们的研究结果表明，CTE可通过抑制碳水化合物消化酶来降低面粉的淀粉消化率、HI和pGI。综上所述，CTE可能是一种能有效降低面粉血糖生成指数的成分。
