Study of sorghum (Sorghum bicolor (L.) Moench) grains fermentation with Lactobacillus plantarum ATCC 14977 on tannin content

Abstract Sorghum is one of the most important source of carbohydrate and protein, but least utilized staple crops because of low nutrient bioavailability. The research aimed to study the fermentation of sorghum grains with Lactobacillus plantarum ATCC 14977 ( L. plantarum ) on tannin content. The study employed two factors experiment of L. plantarum starter cultures concentrations (2, 4, 6, 8, and 10 %) and duration of fermentation. Samples were taken every 12 h during sorghum fermentation (72 h). The viability of microbes, pH, titratable acidity (TA) of the fermentation medium and tannin content of the fermented sorghum grains were measured. The results showed that at the end of fermentation (72 h), the pH decreased from 6.4 to 5.8-6.0, TA increased to 0.59, 0.63, 0.8, 0.95 and 0.88% at a starter cultures concentrations of 2, 4, 6, 8, and 10%, respectively. Tannin content decreased significantly after fermentation for 48 h for all treatments. However, prolonged fermentation from 48 to 72 h did not reduce tannin.