Optimizing the Digested Starch and Starch Digestibility Index of Cardaba Banana Starch Revealed a Multiphasic Starch Digestogram

Abstract

Starch from cardaba banana is modified using octenyl succinic anhydride (OSA), the modification process is modeled using response surface methodology and partial least square regression analysis with the aim of optimizing the starch modification process to produce low digestibility starch. The modified starch is analyzed for digested starch (DS) as well as the starch digestibility index (SDI). The starch digestogram of the optimized starch, as well as the native, is also investigated using a multiphasic approach. The modeling revealed that both the response surface methodology (RSM) and partial least square regression (PLS-R) model predict with high accuracy (r2 [coefficient of determinant] > 0.9) the dependent variables. According to the statistical indices, the RSM model makes a better prediction when compared to the PLS-R model. The optimized conditions for the production of modified starch with low starch digestibility are an OSA concentration of 3.98%, reaction time of 47.45 min, and pH of 10 with a predicted DS of 45.99% and SDI value of 29.86%. Modeling the optimized and native starch digestogram reveals the digestogram follows a multiphasic digestogram with the digestion occurring in three (3) segments. The digestion rate of the starch follows a rapid-slow and slow-rapid in vitro starch digestion rate.