Physicochemical Properties of Fermented Robusta Coffee Pulp Flour by Saccharomyces cerevisiae and Spontaneously

Abstract

The by-product of the coffee industry is the coffee pulp which contains fiber and antioxidant compounds. Fermentation of Robusta coffee pulp flour by Saccharomyces cerevisiae and spontaneously had been done. Fermentation affects the physicochemical properties of flour. This study aimed to determine the effect of S. cerevisiae and spontaneous fermentation on the physicochemical properties of Robusta coffee pulp flour. Robusta coffee pulp was fermented by S. cerevisiae (ScF group, 5 mL of culture stock with a concentration of 2.1×109 cfu/mL) and spontaneously (Sp group, 5 mL of distilled water) for 72 h in a plastic jar. The non-fermented coffee pulp was used as a control (NF group). Fermentation affected the increase in moisture content, crude fiber (not significantly in the SpF group), yellowness value (b*), bulk density, WHC, WAC, OHC, and swelling of Robusta coffee pulp flour. Otherwise, the pH, total phenol, tannin, antioxidant activity (DPPH RSA), and lightness value (L*, not significantly in the ScF group) of fermented Robusta coffee pulp flour reduced following the fermentation process. The redness value (a*) of Robusta coffee pulp flour was not affected by both S. cerevisiae and spontaneous fermentation treatments.