High-humidity hot air impingement blanching (HHAIB) efficiently inactivates enzymes, enhances extraction of phytochemicals and mitigates brown actions of chili pepper

摘要

In current work, high-humidity hot air impingement blanching (HHAIB) was employed to inactivate peroxidase enzymes (POD) of chili pepper under three independent variables, namely blanching temperature (105, 110, and 115 degrees C), relative humidity (20%, 30%, and 40%), and blanching time (30, 60, and 90 s). Response surface methodology (RSM) was used to optimize the blanching conditions based on product POD residual activity and browning index. Results indicated that blanching temperature of 110 degrees C, relative humidity of 40% and blanching time of 38 s were the optimum blanching conditions, which resulted in the minimum POD residual activity (0.52%) and browning index difference (7.09). Validation test showed that the predicted data had good agreement with the experimental data. Results also indicated that compared with the non-blanched samples, the extraction content of ascorbic acid and red pigment from blanched pepper under optimal blanching conditions increased by 42.85% and 8.20%, respectively. Ultrastructural observations explained why moderate blanching can promote the extraction of phytochemicals. The findings in current work indicate that HHAIB can efficiently inactivate enzymes, enhance extraction of phytochemicals and at the meantime mitigate brown actions under optimal conditions.