Chemical, nutritional and sensory evaluation of green beans fermented with and without starter culture.

Abstract

Two varieties of green bean locally known as Binz and Mangtout were fermented with and without starter culture. During fermentation pH changes, total reducing sugars, total acids, thiamine, riboflavin and protein contents were determined. After the pH of the beans had fallen to below 4.0 the beans were pasteurized and sensory evaluation was carried out to assess the taste, texture, aroma and overall acceptability using a 5 point hedonic scale. The pH of the beans fermented with starter culture fell to below 4.0 after 4 days whereas the samples fermented without starter culture took 8 days. In both cases a sharp decrease in sugars and increase in acids were observed within the first two days of fermentation but samples fermented without starter produced significantly less acids. Although there was a significant decrease (p < 0.05) of the vitamins and protein with fermentation period, there were no significant differences between samples fermented with and without starter culture. Overall both varieties produced acceptable fermented products but samples fermented without starter culture were more acceptable than those fermented with starter culture.