Optimization of simple sugar extraction of nagara bean (Vigna unguiculata ssp. Cylindrica) on concentration and proportion of ethanol

Abstract

Nagara bean, the native bean of South Kalimantan, is not only contains carbohydrates and protein, but also contains oligosaccharide fractions such as raffinose and stachiose that can cause flatulence. Raffinosa Family Oligosacharide (RFO) is an undigested carbohydrate that is naturally found in beans. The presence of the oligosaccharide fraction can be identified through reducing sugar and total sugar content in nagara bean. The yield of this fraction depends on the type of material and extraction method, such as the type of solvent, solvent concentration, contact time and extraction temperature. This study was aimed to optimize the extraction of simple sugar fractions on nagara bean at several concentrations of ethanol with various ratio of nagara bean flour to ethanol using the Response Surface Methods (RSM). Optimization was carried out at the center point ethanol concentration of 50% and the ratio of nagara bean flour and ethanol of 1: 10. The optimization results of the simple sugar fraction extraction process in nagara bean flour were obtained at a concentration of 30% ethanol and a ratio of ethanol to nagara bean flour of 10: 1 at extraction conditions at 50° C and extraction time of 30 minutes.