2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center

Previous studies have shown that plasma glucose and insulin responses in human beings vary with the type and physical form of starchy foods digested, and that this effect may be related to enzyme digestion rate. Therefore, foods in which carbohydrates are digested and absorbed slowly might be of interest in relation to the control of diabetes and obesity, by reducing the increase in blood glucose levels after a meal. The objective of this study is to develop a method of making a slowly digestible starch using waxy and non-waxy rice starches. We hypothesize that when starch is heated to the melting temperature and then held for certain amount of time, subsequent cooling and recrystallization would result in decrease of digestibility. Approximately 0.15 g of starch at 20 percent moisture was placed in the air tight stainless steel ampoules and heated to the pre-determined temperature in a Hart Scientific DSC at 1°C per min. Starch was held at that temperature for various time intervals followed by cooling to ambient temperature at the same rate. Digestibility was measured using pig alpha amylase and expressed as mg of maltose. Starches heated to 140°C and held for 60 min showed characteristics of slow digestibility compared to untreated samples. Temperature higher or lower than the temperature of melt did not effect digestibility. Increasing the time of heating up to 60 min at the temperature of melt increased the formation of slowly digestible starch. We conclude that it is possible to make slowly digestible starch by controlling the recrystallization of starches using heat moisture treatment.