Effect of fenugreek (Trigonella foenum-graecum L.) seed extract on glycemic index, in vitro digestibility, and physical characterization of wheat (Triticum aestivum L.) starch

Diabetes is a major health concern and is approaching epidemic proportions worldwide. In 2021, diabetes mellitus was responsible for 6.7 million deaths across the globe. Mortality due to diabetes is predicted to rise nearly 10-fold by 2030 and 783 million by 2045. Wheat starch, which constitutes about 70% of the endosperm, is a key component of wheat grain. The rapid hydrolysis of wheat starch can result in elevated postprandial glucose levels, leading to diabetes. The increase in blood glucose levels is primarily due to carbohydrate hydrolysis, catalyzed by the enzymes alpha-amylase and alpha-glucosidase. Although various medications are available for treating diabetes, most of them are costly and may lead to adverse effects. Natural herbs like fenugreek are recommended in traditional medicine for regulating blood glucose levels. This investigation aimed to study the effect of fenugreek seed extract (FSE) on in vitro starch hydrolysis by pancreatic alpha-amylase and the ultrastructure of starch. Wheat cultivars were characterized for their total starch, amylose content, and resistant starch content, and were screened for their predicted glycemic index. Microscopic studies were conducted to analyze the size and shape of starch granules and to compare native starch with starch treated with FSE. Significant inhibition of enzymatic starch hydrolysis was observed with FSE, with the maximum inhibitory effect caused by 0.2% FSE. These findings suggest that fenugreek could play a role in controlling blood glucose levels by reducing wheat starch hydrolysis and could be effective in managing diabetes.