Enhancement of nutritional properties, and antioxidant and antihypertensive potential of black common bean seeds by optimizing the solid state bioconversion process

Abstract

The aim of this work was to obtain a functional flour with enhanced nutritional properties, and antioxidant and antihypertensive potential from black bean seeds by optimizing the solid state bioconversion (SSB) process using a Rhizopus oligoporus strain. Response surface methodology was applied as optimization technique. A central composite experimental design with two factors [fermentation temperature (FT) = 30–40 °C/fermentation time (Ft) = 6–108 h] and five levels was used (13 treatments). The bioprocessed cotyledons from each treatment were dried, milled, and blended with its previously dried-milled seed coats. The best combination FT/Ft of SSB to obtain the functional flour was 38 °C/100 h. SSB increased the calculated protein efficiency ratio (from 1.59 to 2.40), antioxidant activity (from 13 948 to 22 733 µmol ET/100 g, dw), total phenolic compounds (TPC) (from 190 to 432 mg EGA/100 g, dw) and antihypertensive potential (IC₅₀ from 95.57 to 0.0321 µg/mL). SSB is an effective strategy to improve the TPC of common beans for enhanced functionality.

• Antihypertensive
• antioxidant activity
• bioprocessing
• black bean
• functional ingredient
• optimization

Declaration of interest

This research was supported by grants Programa de Fomento y Apoyo a Proyectos de Investigación (PROFAPI 2012, 2013), Universidad Autónoma de Sinaloa, Sinaloa, México. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.