Optimization of Growth Conditions and Protease Activity for Tempeh Production from Sorghum

Abstract

Fermentation improves the nutraceutical properties of cereals. The objective of this work was to optimize the growth condition for tempeh production from sorghum. Tempeh was developed with sorghum and in combination with soybean. Effective proliferative growth of Rhizopus oligosporus (R. oligosporus) was found on all the substrates. The temperature had a significant effect on the growth of the mould, pH, and protease activity. The incubation temperature of 35OC was found to be more favourable than 30oC. The fermentation at 35oC was completed within 36 hours compared to 30oC (46 h). The pH was raised progressively up to 48 hours of incubation period (7.20-7.25). The protease activity at 35OC was found to be increased until 36 hours and decreased thereafter. The protease activity was found to be significantly higher at 35oC (99.20 IU /g) in comparison to 30oC.