Effect of pre-gelatinization on physicochemical and functional properties of Solenostemon rotundifolius flour

Abstract

Solenostemon rotundifolius is one of the native tubers from Indonesia that has good potential as a flour source. Unfortunately, this kind of potato has poor quality and undesirable functional characteristics so that underutilized in the food industry. Therefore, the processing of Solenostemon rotundifolius into flour product is needed to be modified to improve the quality, obtain the added value of flour, and enhance food product development using a pre-gelatinization treatment. Pre-gelatinization is a hydrothermal process that initiated with boiling and ended with drying. This study evaluated the effect of pre-gelatinization treatment on the physicochemical and functional properties of Solenostemon rotundifolius flour at optimum temperature and time of process (60°C for 7 minutes). The pre-gelatinization treatment produced 89.58 ± 1.47 % yield of flour, reduced the density (0.55 ± 0.02 g/mL) and lightness of flour (71.30 ± 0.14 L value), and declined the amylose content (18.21 ± 1.22 %) compare to the natural flour, while increased the moisture (8.32 ± 0.31 %), ash (3.95 ± 0.06 %), protein (3.43 ± 0.23 %), fat (0.47 ± 0.01 %), starch content (65.11 ± 0.30 %), and amylopectin (46.90 ± 1.51 %). The differences in physicochemical and functional properties were observed among the pre-gelatinization Solenostemon rotundifolius flour with respect to all of parameters. Thus, Solenostemon rotundifolius flour revealed potency as an alternative flour for food diversification and can be used for substituting wheat flour in the various food products.