Modification of hydrolyzed sweet potato starch by retrogradation to enhance slowly digestible starch yield

Abstract

Recently, slowly digestible starch (SDS) and resistant starch (RS) have attracted the great attention of consumers and the food industry due to their beneficial effects on human health. The SDS ingestion resulted in a prolonged release of glucose to maintain the glycemic index (GI) from low to moderate levels. Thus, consumption of SDS might help fully control and prevent hyperglycemia-related diseases, such as cardiovascular disease and diabetes. In this study, the sweet potato starch hydrolyzed by pullulanase enzyme was continuously processed by dual-retrogradation to enhance the formation of SDS. SDS was determined by the analytical method developed by Englyst. Results showed that in the first retrogradation cycle, the obtained SDS content was 44.76±0.37% at 4oC after 48 h of reaction time. The formed SDS content reached 59.72±0.97% at 4oC after 48 h of reaction time in the second retrogradation cycle. As a result, in the whole retrogradation process, the SDS content from sweet potato starch saw a remarkable increase from 15.04% to 59.72%.