Effects of fermentation by Lactobacillus helveticus on the quality and anti-inflammatory potential prediction of pumpkin juice during storage

Lactic acid bacteria fermentation enhances plant beverage quality, yet storage-related mechanisms of fermented pumpkin juice remain unclear. This study investigated effects of fermentation by Lactobacillus helveticus on the physicochemical properties, flavor metabolism, bioactive components, and storage-induced changes in pumpkin juice. L. helveticus fermentation increased total acid content to 3.15 ± 0.03 g/L, total flavonoids to 0.19 ± 0.00 mg RE/mL, and antioxidant capacity to 1.08 ± 0.01 μmol/mL, lowered reducing sugars, and improved storage stability of bioactive components, color, and rheological properties of the juice. GC-IMS identified 63 and GC–MS identified 69 volatile compounds with dominant esters. The fermented samples maintained better flavor stability despite reduction in ester content during storage. Metabolomics revealed eight metabolic pathways to be involved, with fatty acid biosynthesis and phenylalanine metabolism being the core pathways. Network pharmacology demonstrated the fermented juice to have potential anti-inflammatory effects via metabolite-target binding, which supports the development of high-value fermented pumpkin juice products. • Lactobacillus helveticus fermentation enhanced storage stability of pumpkin juice. • Esters are main aroma in fermented pumpkin juice during storage using GC-IMS/GC–MS. • Network pharmacology predicted anti-inflammatory activity of fermented pumpkin juice. • Fatty acid biosynthesis and phenylalanine metabolism are core metabolic pathways.