Controlled fermentation of cotton seeds (Gossypium hirsutum) for Owoh production using bacteria starter cultures

Abstract

This work studied the potential of four bacteria as starter cultures for the fermentation of cotton seeds (Gossypium hirsutum) to produce Owoh condiment. Cotton seed was fermented using spontaneous traditional method and starter cultures. Single cultures of Bacillus subtilis, Bacillus licheniformis, Bacillus pumillus, and Staphylococcus spp. and their combinations with and without Staphylococcus spp. were used as starters for the fermentation at 35 °C for 3 days. Chemical components of fermented and unfermented samples of cotton seeds were analysed for titratable acidity, pH, gossypol and proximate using standard methods. Sensory evaluation of the fermented products was carried out for colour, aroma, taste, stickiness and overall acceptability. Data were analysed using Analysis of Variance (ANOVA) and means separated by Duncan׳s multiple range test. Crude protein, crude fat, crude fibre, ash, moisture content, dry matter, carbohydrate, pH, titratable acidity and gossypol ranged from 22.40% to 13.62%, 28.25% to 15.29%, 11.29% to 2.51%, 3.65% to 1.25%, 39.26% to 55.85%, 60.74% to 44.15%, 34.41% to 67.33%, pH 6.67 to 8.24, 0.36% to 0.02% and 0.004900% to 0.000233%, respectively. Sensory evaluation of the fermented products showed that Owoh produced by the spontaneous or traditional fermentation of cotton seed was not significantly different from Owoh produced with combinations of starters. Although most of the single starter culture did not produce acceptable products in the controlled fermentation of cotton seeds, they played some roles in the product quality. Overall, the use of combinations of isolated Bacillus species with and without Staphylococcus spp. produced Owoh of good quality.