Milk fermentation with prebiotic flour of Vasconcellea quercifolia A.St.-Hil.

Abstract

Non-conventional food plants have bioactive compounds and a high nutritional value. Among these, Vasconcellea quercifolia has nutritional benefits, but it is also easy to cultivate and has a low production cost. In this study, the flour from the unripe fruit of V. quercifolia was evaluated in terms of its potential as a prebiotic for the probiotic bacteria Lactobacillus acidophilus and Bifidobacterium lactis. To do so, fermented milk samples were prepared with 2%, 3%, and 6% of flour and 8.25 log CFU/mL of each microorganism. Samples were analyzed in terms of the number of viable cells of L. acidophilus and B. lactis, as well as pH level, total solids, titratable acidity, and texture in the course of 21days of storage at 4ºC. The obtained microbial viability revealed the in vitro symbiotic effect of flour from V. quercifolia on the probiotic strains of L. acidophilus and B. lactis, which reached 10.20 and 11.19 log CFU/mL, respectively, after 21days of storage, showing a significant difference in cell growth of 1.7 and 2.5 log CFU/mL compared with the control. The pH level decreased from 4.8 to 4.5 after storage time, so it did not alter the conditions for the growth of bacteria. The physical and chemical parameters analyzed did not reveal significant differences (p > 0.05), which indicates product stability. Therefore, flour from the unripe fruit of V. quercifolia has a prebiotic property and can be used as a nutritional supplement for L. acidophilus and B. lactis.