In vitro Digestibility of Starch from Ready-to-Eat Cassava and Corn Flours

Abstract

Abstract Slowly digestible starch (SDS) and resistant starch (RS) associate with health benefits when present in the diet. This study aimed to evaluate ready-to-eat corn and cassava flours regarding their commercial presentation (dry or flaked), composition and in vitro digestibility of starch. Sixteen samples from Southern Brazil were procured in the market: eight dry cassava flours, six biju-type (flaked) corn flours and two biju-type cassava flours. Dry cassava flours had higher L* and lower b* values, and higher RS, relative crystallinity and viscosity peak values. Dry cassava flour partially preserves granular starch, as its processing involves lower drying temperatures and lower moisture of the pressed pulp. Dry cassava flours that had higher b* values also had higher rapidly digestible starch (RDS) levels, since higher temperatures are required in their production. Both biju-type flours showed the highest RDS values and no RS due to processing with elevated temperature and high moisture of the pressed pulp. In this study starch digestibility from the flours depended on processing, with minor influence of the raw material, fiber content and granulometry. The whiter and the smaller the granulometry of the dry cassava flours, the better they showed as potentially health benefiting.

Keywords

• Englyst method
• amylase from porcine gastric mucosa
• resistant starch