Reference Number: 461
Inclusions: Edible flowers
This study aimed to assess the effect of the Clitoria ternatea L. flower extract (CTE), on the inhibition of pancreatic ?-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 ?-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.
Significance of this study to the baker:
Butterfly Pea Flower (Clitoria ternatea) is included in our Botanical Blends here at the Sourdough School. This flower is distributed in tropical zones such as Asia, the Caribbean, and Central and South America. It has historically been used in Ayurvedic medicine of treating stress, depression and anxiety. It is rich in anthocyanins and studies like this one above find that when added to bread it could lower the glycaemic load and the starch digestibility. The study suggests it slows the digestion down in order to be fed on by our beneficial gastrointestinal microbes in the gut, displaying prebiotic behaviour. Further human research is however needed to determine if this is the case.