The Influence of Hot-Air Drying Assisted by Dielectric Barrier Discharge Plasma Pretreatment on the Drying Characteristics and Volatile Components of Carrots

Abstract

To investigate the effect of dielectric barrier discharge (DBD) plasma pretreatment on the hot-air drying characteristics and quality of carrots, experiments were conducted with different pretreatment durations (0 [control], 2, 4, 6, 8 min). The results showed that compared with the control group, the effective moisture diffusivity in the 8 min pretreatment group increased by 1.5 times, and the drying time was reduced from 140 min to 120 min (a reduction of 16%). In terms of color quality, DBD pretreatment increased the redness value of carrots by 179% - 222%. Regarding nutrient retention, the 2 min pretreatment group exhibited the highest carotenoid content (0.2276 mg/g), which was 26% higher than that of the control group (0.1804 mg/g). Compared with the control group, the 6 min pretreatment group showed increases of 25% and 47% in the retention of total phenolics and polysaccharides, respectively. A total of 65 volatile compounds were identified, among which terpenes were the main flavor substances. DBD pretreatment can enhance the drying rate and nutritional quality of carrots, providing experimental evidence for its application in the food hot air drying field.