Sourcing Starter Cultures for Parkia biglobosa Fermentation III: Preparation of Starter Cultures for Industrial Scale Fermentation

Abstract

Aim: To prepare starter cultures for industrial-scale fermentation of Parkia biglobosa, using two strains of Bacillus species, 2B and BC4333. Study Design: Three substrates, African locust bean (ALB), soybean meal (SBM) and de-hulled soybean (SB) were tested for propagation of the bacteria. Four powdered materials, SBM, SB, ALB and Starch (STA) were tested as diluents/carriers for the starter cultures. Place and Duration of Study: Food Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), Pathumthani, Thailand, between June and August, 2011. Methodology: Microbial load, with respect to standard plate count and spore count of milled, dried starter cultures was determined. The potency of the starters to effect fermentation of beans was screened by starter-culture fermentation. Products were analyzed for sensory evaluation, total microbial load and pH. Results: The three substrates, ALB, SBM and SB were found suitable for the propagation of the 2 strains of Bacillus, 2B and BC4333 as starter cultures. The starter cultures can be dried at 60°C for 24h and milled using sterile dry-mill blender. Powdered ALB, SBM, SB and starch were also suitable diluents/ carriers for the stock starter cultures. However, on the basis of physical appearance of products, starch is a preferred carrier. Conclusion: The dried starter culture preparations can be used as inocula for large scale fermentation at ratio ranging: 1 g starter: 33 kg to 1 g starter: 1000 kg of African locust bean substrate.