Effects of the Use of Starter Culture on the Quality of Fermented Parkia biglobosa

The effects of the use of starter-culture on the quality of fermented Parkia biglobosa (‘iru’) were investigated. ‘Iru’ was prepared using fourteen (14) strains of Bacillus subtilis isolated from commercial samples of ‘iru’ as starter cultures. The physicochemical properties, sensory assessment and proximate composition of the unfermented samples, fermented products and commercial samples were determined. The pH values of the starter culture-fermented products ranged between 7.29 and 7.58. However, there was inverse correlation between the total titratable acidity (TTA). The moisture content of the unfermented sample (UFS) 50.67% was higher than that of some of the starter culture-fermented products which ranged between 46.67% and 59.33% while the moisture contents of commercial ‘iru-woro’ (CIW) and commercial ‘iru-pete’ (CIP) were 56.67% and 57.33% respectively. Sensory assessment indicated that the use of Bacillus subtilis strains 2B and 3A as starter cultures for production of ‘iru’ gave more acceptable products than commercial ‘iru-woro’ with values 8.50±0.57a and 8.22±0.06ab respectively. However, products from Bacillus subtilis strain 6C and unfermented samples (UFS) were rated least. The proximate composition result showed that fermentation increased the protein content from 31.26% in unfermented samples to 43.44% and 42.61% in products of Bacillus subtilis strains 3A and 2B respectively. Fat and ash contents of the products also increased in similar trend. However, there was a decrease in carbohydrate and crude fibre contents of the substrate during fermentation. Hence strains 3A and 2B may be recommended for use as starter cultures in commercial production of ‘iru-woro’ and strain BC4333 for commercial production of ‘iru-pete’