Optimization of enzymatic hydrolysis and bioactive compound analysis in NFC summer black grape juice

Objective To develop NFC summer black grape juice.

Methods Using summer black grape fruit as raw material, single factor and response surface experiments were used to optimize the processing technology of summer black grape juice. Based on this, the changes in functional substances before and after and their effects on the antioxidant capacity of NFC summer black grape juice were explored.

Results The optimal process parameters for NFC summer black grape juice were: pectinase addition of 0.003%, enzymatic hydrolysis time of 11.6 h, and enzymatic hydrolysis temperature of 11.2 ℃. The NFC summer black grape juice produced by this process has a pH of 3.48, a soluble solids content of 18.2 °Brix, a total phenol content of 102.75 mg/L, a total flavonoid content of 220.92 μg/mL, and a total anthocyanin content of 231.39 mg/L, which is higher than before the process optimization.

Conclusion Pectinase can increase the content, physicochemical indicators, and antioxidant capacity of polyphenols and flavonoids in NFC summer black grape juice. After process optimization, the juice appears bright purple, with a mellow taste, sweet aroma, and rich fruit flavor. This provides a scientific basis for the development of NFC summer black grape juice technology and related products.