POTENTIALS OF TWO LACTOBACILLI IN PROBIOTIC FRUIT JUICE DEVELOPMENT AND EVALUATION OF THEIR BIOCHEMICAL AND ORGANOLEPTIC STABILITY DURING REFRIGERATED STORAGE
MOHAMMAD A. HOSSAIN 1*, RANA DAS 2, MD. YASIN 1, HUMAYUN KABIR 1, TANVIR AHMED 1 1. Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
2. Department of Food Engineering and Technology, State University of Bangladesh, Dhaka 1205
*Corresponding Author: mahossain-fet@sust.edu
In this study, two probiotic lactobacillus strains, such as Lactobacillus fermentum and Lactobacillus plantarum, were inoculated in apple and star fruit juices to develop probiotic juices. The main aim of this study was to test the suitability of these two strains in the fruit juices, and also assess the change of biochemical and sensory properties under chill (4 °C) storage. For each fruit juice, three probiotic juice samples were prepared by inoculating with 1 % L. plantarum, 1 % L. fermentum, and the mixture of both L. fermentum and L. plantarum (0.5 % each) and compared with the control sample (juice with no lactobacillus strain). The changes in pH, acidity, protein, total soluble solid, total cell count, and sensory properties of samples were studied at every seven-day interval at 4 °C for three weeks. The results revealed that the pH, protein, and total soluble solids (TSS) of both probiotic juices, decreased slightly with increasing storage time. At the same time, acidity contents showed a reverse trend. It was found that both L. fermentum and L. plantarum sustained well in fruit juices, though the highest bacterial cell count was found on 7th day of storage for both probiotic juices. Notably fruits juices with L. fermentum supported more cell growth than the juice samples with L. plantarum. Regarding organoleptic analysis, overall sensory scores of fermented apple and star fruit juices including control samples slightly decreased with increasing storage duration. Overall, the study insinuated that two lactobacilli did not put forth any inferior properties of fruit juice samples compared to the control samples regarding physicochemical and sensory properties. Therefore, apple and star fruit juices could be viable media for the growth of L. fermentum and L. plantarum as potential probiotics.
