Improvements in the functions of probiotic-based mango pulp rich in phenolic and proline antioxidants by treatment with pectinase and fermentation with lactic acid bacteria
Areeya Laophongphit, Surasak Siripornadulsil, Wilailak Siripornadulsil
Abstract
The pulp, juice, and pomace of yellow fruits contain a variety of bioactive compounds. The antioxidant activity was relatively high in pulp, and this part was thus selected for further processing. In Mahachanok mango pulp, pectinase-and-heat treatment significantly increased phenolic content but did not affect carotenoid content and antioxidant capacity. The quality of Mahachanok mango pulp was improved using pectinase and/or heating, and fermentation with lactic acid bacteria (LAB). DPPH and ABTS assays indicated that all LAB strains significantly enhanced phenolic levels (>100%) and antioxidant activity (>300%). Lacticaseibacillus paracasei OR1 could grow effectively in fermented mango pulp, and the cell numbers increased from 6 to 10 log CFU/g. The highest OR1 cell numbers were found in mango pulp after pectinase-and-heat treatment, which released a substrate suitable for OR1 growth. The total phenolic contents and antioxidant activities of all OR1-fermented samples were significantly higher than those of non-fermented mango pulp. OR1 fermentation increased the proline content in mango pulp by 317% in the pectinase-and-heat-treated sample and 200% in the pectinase-treated sample and reduced contamination by yeasts, molds, fecal coliforms, and other bacteria. Therefore, healthy probiotic-based foods rich in phenolic and proline antioxidants could be produced by pectinase-and-heat treatment and LAB fermentation.