The Potentials of Lime (Citrus aurantifolia) for Improving Traditional Corn Fermentation for Probiotic Lactic Acid Bacterial Proliferation

Abstract

Lactic Acid Bacteria (LAB) as probiotic organisms can be sourced from fermented diary and vegetable products. The problem in Nigeria is their affordability to the greater populace, as the common sources are relatively expensive. The study was aimed at sourcing for a low cost meal rich in probiotic LAB by utilizing raw lime juice for the fermentation of corn. Washed yellow corn variety (6%) was fermented using prepared lime solution (pH 5.1-5.5). The lime-fermented corn was wet-milled, sieved and the resulting substrate was enumerated for LAB and coliform on DeMan Rogosa Sharpe’ agar and MacConkey agar plates respectively. The predominant LAB were characterized as Lactobacillus fermentum, Lactobacillus plantarum and Lactobacillus acidophilus. At their predetermined optima growth periods (18 h, 22 h and 24 h), they were evaluated for antimicrobial potentials against Salmonella typhi, Shigella dysenteriae and Candida albicans. Their resistance to acid, bile and antibiotics was determined. The LAB (>3.80 x 10⁸±012 cfu/ml) recovered from lime-treated samples were significantly (p<0.05) higher than that from untreated samples (<5.70 x 10⁶±003 cfu/ml). The pH (<5.3) and coliform counts (<0.50 x 10¹±013) were also reduced in the treated sample. Although their antibiotic resistance was very low, the test LAB especially L. acidophilus demonstrated efficient probiotic properties by inhibiting the test pathogens, maintaining >78% acid stability at pH 3 and withstanding up to 20% bile concentration at 51.4% survival rate. These results reveal that low cost lime-fermented corn is a rich source for probiotic LAB and thus can be recommended as a food supplement.