Study the effect of ultrasonic pretreatment combined with electrohydrodynamics on drying characteristics and volatile components of carrots

Abstract

In order to comprehensively and systematically explore the effects of ultrasonic pretreatment combined with electrohydrodynamic (EHD) on the drying characteristics and volatile constituents of carrots. In this experiment, ultrasonic pretreatment assisted by EHD drying method with different power values was used to study carrots. Drying characteristics, rehydration capacity, shrinkage capacity, color, infrared spectra, and volatile components of carrots were measured and analyzed. Ten mathematical models were used to fit the drying of carrots. The results showed that ultrasonic pretreatment can significantly enhance the drying rate of carrots in the electrohydrodynamic system, the rehydration rate had a tendency to increase and then decrease with the increase of ultrasonic power, and the rehydration rate of carrots reached the maximum value under the condition of 240 W. The best performance in terms of color and infrared spectrum was achieved at 180 W. A total of 212 volatile compounds were detected in the dried carrot products, of which 6-methyl-5-hepten-2-one, as a carotenoid degradation product, was the least abundant at 180 W, indicating the best retention of carotenoids at this power pretreatment condition. The Midilli et al. mathematical model was best described the drying process of carrots. This work provides an experimental and theoretical basis for ultrasonic pretreatment combined with EHD in the field of carrot processing.

Keywords

• Ultrasonic pretreatment
• Electrohydrodynamic (EHD) drying
• Carrot
• Volatile components
• Mathematical modeling