Drying of Banana Using Combined Low-pressure Superheated Steam and Vacuum Drying

Aiming at the problem that it is difficult to guarantee higher drying rate and the quality of banana dried by low-pressure superheated steam. A method of combined low-pressure superheated steam and vacuum drying was proposed to increase the drying rate and reduce the temperature of banana to improve the product quality. The inversion temperatures of banana investigated by the falling rate period and the whole drying period were 88.75℃ and 89.06℃, respectively. The drying kinetics and product quality were studied at 90℃ for combined low-pressure superheated steam and vacuum drying. The results showed that the maximum temperature of samples of combined low-pressure superheated steam and vacuum drying was 8.5℃ lower than that of low-pressure superheated steam drying and the drying time was 30 min lower than that of vacuum drying. Compared with low-pressure superheated steam drying and vacuum drying, the number of peaks was increased by 38.27% and 41.77%, and the first fracture attenuation was reduced by 7.37% and 36.03%, respectively. Therefore, the crispness of dried banana slices of combined low-pressure superheated steam and vacuum drying was enhanced. In addition, the pore structure of dried banana slices was rich. The color quality of combined low-pressure superheated steam and vacuum drying was better than that of low-pressure superheated steam drying and vacuum drying. The VC retention was 67.9%, which was increased by 255% and 191% respectively than thta of low-pressure superheated steam drying and vacuum drying. © 2022, Chinese Society of Agricultural Machinery. All right reserved.