Influence of storage temperature and autoclaving cycles on slowly digestible and resistant starch (RS) formation from partially debranched rice starch

Abstract

In this study, optimum conditions to produce slowly digestible starch (SDS) and RS from rice starch were investigated as a function of pullulanase concentrations, storage temperature, and autoclaving-cooling cycles. Then, the physicochemical properties of the rice starches obtained were compared with native rice starch. Response surface methodology (RSM) was used to evaluate the effects of independent variables, namely the enzyme (pullulanase) concentration (X1), storage temperature (X2), and autoclaving-cooling cycle (X3) on the production of SDS and RS fraction. The optimum conditions for SDS and RS occurred in the treatment with application of pullulanase at 482 and 610 mu L, and storage temperature at 36 and 63 degrees C with autoclaving cycles of three times, respectively. SDS and RS obtained through optimum conditions showed higher amylose content and water solubility index as compared to native starch. While the SF and water absorption index were lower than native starch. The extent of hydrolysis -amylose decreased in the order cooked starch>SDS>RS>native starch. SDS and RS had lower RVA parameters (except pasting temperatures) than native starch.