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

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.