Enzyme activity and nutritional profile of different-sized carrot cubes treated with supercritical carbon dioxide

Abstract

This study evaluated changes in the enzyme activity, color, carotenoids, sugar profile, individual phenolic compounds, and antioxidant capacity of supercritical carbon dioxide (SCCD)-treated carrot cubes of different sizes (1 cm and 2 cm). Results demonstrated that SCCD reduced the activities of polyphenol oxidase (PPO) and peroxidase (POD) more in 1 cm carrot cubes than in 2 cm carrot cubes. Nevertheless, the a* , b* , and ∆E values of 1 cm SCCD-treated were enhanced compared to 2 cm SCCD-treated samples. The carotenoids, phenolic compounds, and antioxidant capacity of 1 cm SCCD-treated samples were increased under moderate processing conditions. In contrast, the nutritional composition in 1 cm SCCD-treated samples was lower than in 2 cm SCCD-treated samples at harsh processing conditions. The principal component and correction analysis displayed a visual variation between the enzyme activities and nutritional composition of 1 cm and 2 cm carrot cubes after SCCD processing. According to the results above, 1 cm carrot cubes processed with SCCD at 10 MPa, 35 ℃, and 45 min are the most effective at preserving fresh-cut carrots with relatively high enzyme inactivation and the highest retention of bioactive compounds. This work provides a more comprehensive theoretical basis for optimizing SCCD processing for fresh-cut carrots and recommendations for industrial production.