FERMENTATION OPTIMIZATION FOR A SYMBIOTIC MANGO JUICE (Mangifera indica L.)

Symbiotics are functional foods that contain probiotics and prebiotics that promote health. Most symbiotics are of dairy origin. However, fruits have been suitable alternatives for the production of these products, because they contain vitamins and minerals, as well as good acceptance by sensory characteristics. Thus, the study aimed to evaluate the conditions of fermentation of Lactobacillus casei NRRLB-442 in symbiotic mango juice. Therefore, the fermentation conditions were studied through a central composite rotated experimental design, with 11 assays, changing the initial pH from 4.29 to 7.11 and FOS from 9.64 to 80.36 g/L, respectively. All tests were inoculated with 7.00 log CFU/ mL of L. casei and incubated at 30 ºC/ 24 h. After, the microorganism viability was determined. The results were analyzed by Response Surface Methodology. After determining these conditions, the beverage was fermented and measurements of viability and pH were done each 2 h, during 24 h to determine the proper fermentation time. As a result of the experimental design, L. casei viability increased, as 7.00 log CFU/ mL were inoculated in all assays and after 24 h they had counts higher than 9.00 log CFU/ mL. This result is satisfactory since it is higher than the minimum value established in the literature (6.00 log CFU/ mL) for probiotic to exert beneficial effects. For kinetics, the viability increased up to 14 h of fermentation (9.96 log CFU/ mL), with a reduction to 9.11 ± 0.02 log CFU/ mL with 24 h. Although maximum viability was obtained at 14 h, the fermentation time of 10 h was chosen because the pH reduced to 4.44. The pH of 4.5 inhibits the growth of pathogens. Thus, the optimum conditions for symbiotic mango juice production were pH 6.60 and 59.36 g/ L FOS and ideal fermentation time of 10 h.