P-1 5 EFFECTS OF SOAKING WITH PULLULANASE TREATMENT ON PROPERTIES AND DIGESTIBILITY OF COOKED RICES

研究主題

P-1 5 EFFECTS OF SOAKING WITH PULLULANASE TREATMENT ON PROPERTIES AND DIGESTIBILITY OF COOKED RICES

研究摘要

Cooked rice is readily hydrolyzed by amylases after ingesting, resulting in a high glycemic index. Slowly digestible starch (SDS) and resistant starch (RS) offer a slow increase of postprandial blood glucose level and many other health benefits. Pullulanase can selectively cleave 1,6-α-D-glycosidic bonds at branching points, leading to the generation of linear short amylose with low molecular weight. Debranched starch is a good source of SDS and RS. Most literature focuses on debranching of isolated starch. The purpose of the study was to investigate the effects of soaking rice kernels with pullulanase on properties and digestibility of cooked rices. Waxy rice (WR) and low-amylose rice (LAR) were soaked at 65 oC for 2 h with different levels of pullulanase (0-900 NPU/100 mL). The results showed that the optimum pullulanase concentrations for WR and LAR were 700 and 300 NPU/100 mL. As the pullulanase increased, the solid content leached from soaked rice increased significantly. Soaking at the higher pullulanase concentration decreased integrity of raw rice grains, and cooked LAR had more breakage than cooked WR. Furthermore, the SDS and RS of cooked rice at the optimum pullulanase concentration were 17.2% and 5.31% for WR; and 21.66% and 4.73% for LAR. The pullulanase treatment slightly decreased estimated glycemic index (eGI) of WR from 100.79 to 95.08 and LAR from 90.03 to 87.57. Except the lower appearance score due to some broken rice, the sensory evaluation indicated soaking with pullulanase treatment improved aroma for both WR and LAR, but increased hardness and deceased stickiness for WR.

作者

Yi-yuan SHAO(邵貽沅), Yi-ling YANG

發表研討會

Vienna (Austria)2019年