Drying characteristics and optimization of ultrasound-strengthened cold air drying combined with sequential far-infrared radiation drying on potato

摘要

To improve the dehydration rate and product quality of potatoes, a new strategy utilizing ultrasound-strengthened cold air drying combined with sequential far-infrared radiation drying (UCAD-FIRD) was proposed. The results prove that UCAD greatly promotes dehydration speed, and stronger ultrasound power results in higher drying rate. Compared with UCAD process, UCAD-FIRD drastically shortens the required drying time. Potato slices dried by UCAD-FIRD retain more nutrients compared with those dried by UCAD alone, exhibited by lower color variations and a greater rehydration ratio. For example, total phenol content and Vitamin C content rise first and then, decline but still remain at a high level. The Gray Correlation Analysis is applied to obtain the best experimental group as follows: cold air temperature of 15°C, radiation temperature of 140°C, ultrasound power of 60 W. Therefore, the drying strategy of UCAD-FIRD can remarkably accelerate the drying rate and simultaneously improve the product quality.