EVALUATION OF PROBIOTIC POTENTIALSOF MUCUNA BEANS FLOUR FERMENTEDWITH Lactobacillus SPECIES

Abstract

Mucuna beans flour fermented with three different Lactobacillus species was evaluated in vitro and in vivo for probiotics activities in this investigation. The Lactobacillus species used were isolated from neonate faeces (L. acidophilus) and traditionally fermented ogi made from sorghum (L. plantarum and L. fermentum) thereafter, they were screened for growth and survival in acidified water, 7.5% salt and 10% bile as well as in the mucuna beans flour. There was a steady increase in the total titratable acidity and temperature with concomitant reduction in the pH of samples during the fermentation period. The greatest reduction in pH was observed in mucuna beans flour fermented with L. acidophilus (6.77 to 3.07) while the lowest reduction was observed in the flour fermented with L. fermentum (6.72 to 4.05). also, the flour fermented with L. acidophilus had the highest acidity of 2.22% after 72 hours fermentation period compared to L. plantarum and L. fermentum which had 1.98 and 1.28% respectively. At the end of 72 hours fermentation at 370C, all the Lactobacillus species showed appreciable growth in the flour. After storage for 14 days at refrigeration (4±20C) and room temperature (25±20C), there was a significant increase (p≤0.05) in the Lactobacilli found in the products stored at room temperature compared to the one stored at refrigeration temperature. The proximate analysis showed that there was significant increase in the protein and moisture contents with decrease in carbohydrate, fat, fibre and ash contents of the fermented samples compared to the unfermented sample. Under varying temperature, salt, pH range and bile concentration, L. acidophilus showed the highest growth and survival rate followed by L. plantarum while the least rate was recorded in L. fermentum. Supplementing the diet of albino rats infected with Escherichia coli and Shigella dysenteriae with fermented products reduced significantly (p≤0.05) the numbers of these pathogens and other enteric bacteria while the number of Lactobacilli increased considerably. Moreover, the group fed with mucuna beans flour fermented with L. acidophilus showed a better performance than the group fed with mucuna beans flour fermented with L. plantarum. Furthermore, the body weight of the rats fed with the fermented product (220g) was significantly (p≤0.05) higher than that of the control group (192g). The animals infected with pathogens and then fed with fermented mucuna beans flour had higher body weight at the end of the experiment compared with those infected without any further treatment. Also, the haematological analysis showed that the rats infected with the pathogens and later fed with the fermented mucuna beans flour recovered fully since their values were within the permissible limit and were not significantly (p≤0.05) different from the control group. In all, the rats fed with the mucuna beans flour fermented with L. acidophilus showed good recovery compared to the controls. Conclusively, these results suggest that mucuna beans flour fermented with L. acidophilus could be used as an ideal probiotic food.