Effects of high hydrostatic pressure and thermal processing on anthocyanin content, polyphenol oxidase and β-glucosidase activities, color, and antioxidant activities of blueberry (Vaccinium Spp.) puree

Thermal processing (TP) and high hydrostatic pressure (HHP) are two important puree processing methods. In this study, the polyphenol oxidase (PPO) and beta-glucosidase activities, chromatic values, peroxide radical scavenging capacities (PSCs), cellular antioxidant activities (CAAs), and anthocyanin profiles were evaluated in blueberry puree following TP and HHP treatments. Nine anthocyanins were identified and cyanidin glycosides were the most abundant compounds in the blueberry puree sample. Petunidin-3-O-arabinoside, malvidin-3-O-galactoside, and malvidin-3-O-glucoside concentrations increased at temperatures of 70-90 degrees C (TP) and a pressure of 300 MPa (HHP). The highest total anthocyanin concentration (503.5 mu g/mL) and PSC (13.45 mu g VCE/ mL) were observed following the TP (90 degrees C) treatment. Furthermore, a positive correlation was observed between the anthocyanin content and PSC (R-2 = 0.655, P < 0.05). Finally, HHP treatment resulted in better puree color retention than TP treatment. The results of this study could provide valuable information for optimizing the processing methods for anthocyanin-rich products.

Automated summary

Thermal processing and high hydrostatic pressure treatment affect the anthocyanin content and antioxidant activity in blueberry puree, with the optimal effect observed at 90 degrees Celsius for TP treatment and better color retention for HHP treatment.