ABSTRACT

This work explores 10 days fermentation of beetroot juice using Lactic Acid Bacteria (Lactobacillus plantarum and Lactobacillus bulgaricus) which was carried out to enhance the nutritional quality and shelf life of beetroot. Beetroot was analyzed using the standard methods for proximate analysis. Carbohydrate was calculated by difference, the mineral content of beetroot was determined by the dry acid extraction method. Lactic acid bacterial load during the course of fermentation was checked by pour plate technique. Proximate analysis of beetroot showed that there was increase in nutrient composition during the course of fermentation. Result of proximate composition of beetroot (Beta vulgaris) indicates that the highest protein content was achieved with L. bulgaricus (1.87%) on the 10th day of fermentation. The fat decrease as fermentation proceeds and the highest decrease occurred in L. bulgaricus fermented juice (0.04%). The percentage ash increased slightly in both fermented juices but higher in the fermented juice inoculated with L. bulgaricus (1.19%). The moisture content decreased and the highest decrease was achieved with L. bulgaricus (84.44%). Carbohydrate content increased and was higher in the sample inoculated with L. bulgaricus (12.46%). The result in mineral content of the fermenting beetroot juice decreased significantly with L. plantarum and L. bulgaricus as fermentation time increase. The decrease in calcium was higher with L. plantarum (1.68mg/100ml). Magnesium also reduced and the decrease was higher with L. plantarum (1.12mg/100ml). Similarly, potassium and sodium reduced significantly with fermentation time and the highest decrease was achieved with L. plantarum (3.17mg/100ml and 6.92mg/100ml respectively). The decrease in phosphorus was higher in L. bulgaricus fermented juice (13.34mg/100ml). The result of Lactic acid bacterial load shows that there was an initial high increase from the zero day to the 2nd day on both fermenting juice. Then, a maximum increase was recorded for both Lactobacillus species after 4 days of fermentation whereby the mean Lactic acid bacterial loads stood at 2.08 × 107 CFU/ml and 2.56× 107 CFU/ml for L. plantarum and L. bulgaricus fermented juice respectively. From the 6th day of fermentation, a decline was recorded for both sample in which the load decreased from 2.08 × 107 CFU/ml to 1.01 × 107 CFU/ ml at the 10th day of fermentation by L. plantarum while the load decreased from 2.56 × 107 CFU/ml to 1.18 × 107 CFU/ml in L. bulgaricus fermented beetroot juice. This result reveals that the beetroot juice contain appreciable amounts of nutrients that justifies its use in treatment of different ailments and also its fermentation will make it a good functional beverage.