Effect of Lactiplantibacillus plantarum NCU001557 Fermentation on the Physicochemical Properties, Bioactivity, Volatile, and Nonvolatile Compounds of Benincasa hispida (Winter Melon) Juice

Benincasa hispida (winter melon), a widely consumed vegetable, is known for its rich array of bioactive compounds in its pulp. This research focused on investigating how fermentation with Lactiplantibacillus plantarum NCU001557 affects the physicochemical characteristics, bioactivity, and flavor profile of B. hispida. The results demonstrated that the pH and reducing sugar content significantly decreased upon fermentation's completion, while the titratable acidity and organic acid content notably increased. The viable bacterial count was measured at 8.890 Log CFU/mL, and the total phenol content rose to 81.31 mg GAE/L. Additionally, the antioxidant capacity and xanthine oxidase (XO) inhibitory activity showed significant enhancement. Moreover, fermentation reshaped the volatile compound profile, characterized by increased levels of ketones, esters, acids, and alcohols, alongside a decrease in aldehydes. UHPLC-QTOF-MS analysis of the nonvolatile compounds revealed that L. plantarum NCU001557 significantly altered the nonvolatile metabolites of B. hispida, including caffeyl alcohol, m-coumaric acid, and trans-cinnamic acid. These metabolites may contribute to the enhanced bioactivities of B. hispida. These findings suggest that fermented B. hispida pulp has promising potential as a functional food with significant application value. PRACTICAL APPLICATIONS: This study offers important perspectives on the nutritional significance of Benincasa hispida and its potential for uric acid-lowering applications in product development.