Effect of Natural Fermentation Period on Nutritional, Anti Nutritional, I Total Phenols, Flavonoids and Antioxidant Contents of Finger Millet Flour
V. F. Abioye
Department of Food Science, Faculty of Food and Consumer Sciences, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria.
J. A. Adejuyitan *
Department of Food Science, Faculty of Food and Consumer Sciences, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria.
A. O. Adeoye
Department of Food Science, Faculty of Food and Consumer Sciences, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria.
I. O. Gbadegesin
Department of Food Science, Faculty of Food and Consumer Sciences, Ladoke Akintola University of Technology, P.M.B. 4000, Ogbomoso, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Aims: This study determined the changes in the chemical and nutritional composition of naturally fermented finger millet studied at ambient temperature (28±2°C) for 72 h.
Study Designs: Finger millet seeds were cleaned and fermented (72 h; 28±2°C). Samples were taken at 24 h interval and dried at 50°C for 48 h.
Methodology: The fermented finger millet samples were analyzed for microbial, biochemical changes, chemical, proximate and mineral composition.
Results: Biochemical changes showed a drop in pH from 6.74 to 6.04 while titratable acidity (lactic acid equivalent) increased from 0.04 to 0.62% after 72 h. The moisture, protein, ash, fat, fibre and carbohydrate were in the ranges of 7.08-9.449%; 5.31-7.274%; 1.10-3.392%, 1.296-2.47%, 1.154-2.46% and 77.44-81.58%, respectively. Significant increase were observed in the mineral composition with phosphorus, potassium, calcium, sodium, and iron identified in the fermented finger millet flour in the ranges of 93.5-176 mg/100 g; 171-247.5 mg/100 g; 87.04-196.5 mg/100 g; 1.30-3.075 mg/100 g and 5.28-11.95 mg/100 g, respectively. Tannin, oxalate, phytate and trypsin were in the ranges of 1.537 to 3.23 mg/100 g; 0.875 to 1.59 mg/100 g; 0.195 to 0.85 mg/100 g. and 2.731 to 6.23 mg/100 g, respectively. The total phenols and total flavonoids ranged between 11.605-40.29 mg/ 100 g and 63.36 -172.872 mg/100g while the 2,2-diphenyl-1-picrylhydrazyl (DPPH) of the flour samples ranged between 28.109 and 68.238 mg/ml. Microorganisms identified were Bacillus cereus, Lactobacillus Plantarum, Lactobacillus casei and Lactobacillus brevis. This study shows that fermentation decreased the anti-nutrients, increased the proximate and minerals contents and also improved the anti-oxidative properties of finger millet flour.
Keywords: Finger millet, fermentation, anti-nutrients, antioxidants