Effect of a Modified Atmosphere on Drying and Quality Characteristics of Carrots

Many quality degradation problems are related to the high O-2 content of normal air atmosphere during drying. To reduce O-2 content in drying atmosphere and obtain food products with high quality, modified atmosphere drying was conducted. In this study, carrots were used as experimental materials to investigate the effects of drying parameters on the drying characteristics and product quality. Results showed that the increase in drying temperature and the decrease in O-2 content positively influenced drying rate and effective moisture diffusivity. High carotenoid content, ascorbic acid retention ratio, and rehydration ratio were produced with low drying temperature and O-2 content. The color parameters of products were highly correlated with carotenoid content, and low color difference could be achieved as drying temperature and O-2 content decreased. Drying temperature and O-2 significantly influenced carotenoid content, ascorbic acid content, rehydration, and color difference of dried products. Good quality parameters were obtained only at low drying temperature under the drying condition of normal atmosphere and could be achieved at drying temperatures of 40 to 70 A degrees C when O-2 content is 5 %. Therefore, the modified atmosphere drying is a promising method to protect the quality of dried products.