Research On The Screening Of Low Glycemic Index Rice And The Effect Of Rice On Lowering Blood-glucose

Owing to the enormous change of people’s living habit and dietary structure, the numberof people with diabetes is on rise year by year. In addition to medication treatment, dietarytherapy as an adjuvant therapy also is one of the major initiatives to control the developmentof diabetes. Rice is one of the staple food of residents in our country. Due to the diversity ofthe varieties of rice, it is necessary to select rice which is suitable for diabetic to eat. The maincontents of this paper were as follows: first, available carbohydrate digestion rate (ACH) andchemical composition of different varieties of rice were analyzed; then, postprandial bloodglucose response of different varieties of rice were measured by the animal experiment;finally, the pasting properties and textural properties of different varieties of rice werecompared and the correlation of the pasting properties, textural properties and chemicalcomposition, postprandial blood glucose response was analyzed.The conclusion of experiment on human gastrointestinal digestion in vitro: White japonicawas served as the standard reference food, we set the glycemic index (GI) of White japonicaat100. The estimated GI of Bridge rice (52.12±0.87) and Thailandnuo (54.97±0.92) weresignificantly lower than other varieties of rice (P<0.05). The conclusion of the correlationanalysis between estimated GI of rice and chemical composition of rice: ash, fat, protein,dietary fiber(DF) and resistant starch(RS) had significant correlation with estimated GI(r=-0.837**, r=-0.764**, r=-0.740**, r=-0.871**, r=-0.585**)(P<0.01), but amylose/amylopectinhad no significant correlation with estimated GI(r=-0.238)(P>0.05). The conclusion of thecomparison on the digestion rate of ACH of rice in different cooking process: longer soakingtime and cooking time, higher proportion of rice to water, and cooking rice with distilledwater significantly increased the digestion rate of ACH of rice (P<0.05). Storage in refigeratorsignificantly reduced the digestion rate of ACH of rice (P<0.05), but the reducing effect ofre-steaming reatment was not significant (P>0.05). Added ingredient could change thedigestion rate of ACH of rice. Locust bean gum, monoglycerides and sesame oil significantlydecreased the digestion rate of ACH of rice (P<0.05). Salt increased the digestion rate of ACH of rice, but the effect was not significant (P>0.05). The digestion rate of ACH ofrice–chickpea mixed food by cooking respectively was significantly lower than that of thecorresponding rice (P<0.05).The conclusion of animal experiments: incremental area under curve (IAUC) for bloodglucose response of healthy rat and type I, type II diabetes rat after intaking of Bridge rice,Xinfeng No.2and Thailandnuo were significantly lower than White japonica (P<0.05). Therewas no significant difference between IAUC of healthy rat and type II diabetes rat afterintaking of rice by addition of all ingredients (except salt) and that of the corresponding rice(P>0.05), but IAUC of type II diabetes rat after intaking of rice by addition of salt wassignificantly higher than that of the corresponding rice (P<0.05). IAUC of healthy rat and typeII diabetes rat after intaking of rice–chickpea mixed food by cooking respectively weresignificantly lower than that of the corresponding rice (P<0.05).The conclusion of analysis on pasting properties and textural properties of rice: theedible quality of Thailandnuo, Black rice, Pearlnuo, Chunuo was better than other varieties ofrice, at the same time, the addition of monoglycerides, locust bean gum could significantlyimprove the edible quality of rice (P<0.05). In addition, refrigeration and reheating couldsignificantly reduce the edible quality of rice (P<0.05). The conclusion of the correlationanalysis between RVA profile characteristics, textural parameters of rice and chemicalcomposition, IAUC of rice: amylase content (AC) had highly significant correlation withRVA profile characteristics (P<0.01). AC, protein content and RVA profile characteristicshad significant correlation with textural parameters (P<0.05). But RVA profile characteristicsand textural parameters had no significant correlation with IAUC (P>0.05).