INFLUENCE OF pH AND ACIDITY ON THE FERMENTATION OF FINGER MILLET SPICED OGI

Abstract

The purpose of this research work was to evaluate the effect of ginger and garlic on the fermentation dynamics of finger millet made ogi. It is important to allow cereals achieve acidification during fermentation in order to improve the organoleptic properties and safety of the product. Spiced finger millet (FM) ogi was produced in the ratios of 100% FM, 99% FM: 1% ginger, 95% FM: 5% ginger, 90% FM: 10%, 99% FM: 1% garlic, 95% FM: 5% garlic, 90% FM: 10% garlic. The data generated were subjected to statistical analysis and means were separated using Analysis of Variance. The results of microbial associations of spiced finger millet ogi samples investigated at 48 h during the secondary fermentation stages ranged from (5.0×10³ – 43.0×10³) cfu/ml for total bacteria count, (1.0×10³ – 3.0×10³) cfu/ml for total fungi count, (2.0× 10³ – 10.5× 10³) cfu/ml for total coliform count and (7.5×10³ – 70×10³) cfu/ml for total LAB count. All the isolates that were catalase negative, gram positive, non-spore forming were identified as lactic acid bacteria and sugar fermentation pattern revealed that they belong to the specie of Lactobacillus. During steeping the acidity increased with consequent drop in pH, the trend which was sustained during the souring stage, the pH decreased gradually (p<0.05) from 5.98 to 4.01 at 10% garlic inclusion, while it decreased significantly (p<0.05) from 5.54 to 3.42 at 10% inclusion of ginger.