Effect of high hydrostatic pressure on the quality-related properties of carrot and spinach

This study was designed to evaluate the potential effectiveness of high hydrostatic pressure (HHP) on the changes in quality-related properties of carrot and spinach as measured by ascorbic acid, carotenoids, phenols, flavonoids, microstructure, enzyme activity, and antioxidant activity. Better retention of ascorbic acid and carotenoids was observed at the carrots and spinaches treated at 100, 300, and 500 MPa for 20 min compared to the thermal processing. The color differences were noticeable at the carrot treated at 500 MPa (ΔE=3.5) and the spinach treated at 100 MPa (ΔE=3.6). The least residual peroxidase (POD) activity was 16.6% at the carrot at 300 MPa. The residual polyphenoloxidase (PPO) activities were decreased in carrot (15.1-6.9%) and spinach (31.1–21.3%) and the amounts of phenols flavonoids were increased with increasing pressure levels, leading to the enhanced antioxidant activity. Therefore, the HHP could be used as an alternative for improving quality of vegetables.