[Background/Aims] In order to prevent obesity and diabetes, it is important to avoid overeating, especially carbohydrates. Therefore, we evaluated the effect of taking jumbo leek bulb before a meal on the decomposition and absorption inhibition of carbohydrates after a meal. In this case, we used a product that was heat-treated after promoting phase transition of its content by rapid and synchronized dormancy-breaking (RSDB), and investigated by decreasing two enzyme activities, namely pancreatic α-amylase and α-glucosidase, and report the results.

[Results] In pancreatic α-amylase, 6.5% inhibition of enzyme activity was observed in the untreated (heat and lyophilized) without RSDB compared to the control. In contrast, the RSDB inhibited it more effectively by 12.5%. In the case of α-glucosidase, 9.1% of inhibition of enzyme activity was observed in the untreated, whereas 14.6% was inhibited by the RSDB treatment, about 1.6 times more effective than the untreated. Thus, the RSDB jumbo leek bulb, when taken before a meal, was found to inhibit postprandial carbohydrate decomposition and absorption (postprandial hyperglycemia prevention effect). It is possible that the inulin in the jumbo leek has an inhibitory effect on glucose absorption by wrapping the carbohydrates, but the RSDB treatment may have accelerated the effect. Furthermore, an enhancement effect of insulin production and efficiency is expected by organosulfur compounds. In conclusion, the high efficacy of the RSDB jumbo leek in suppressing postprandial carbohydrate degradation and absorption was observed in a model experiment. The RSDB jumbo leek bulb is expected to be effective in preventing obesity and diabetes.