Ultrasonically enhanced low-temperature microwave-assisted vacuum frying of edamame: Effects on dehydration kinetics and improved quality attributes

Abstract

Using ultrasound (US) at microwave-assisted vacuum Frying (MVF) program was investigated to acquire better process efficacy and bodily high-quality attributes of fried edamame. Different power degrees of US (0, 150, 300, 600 W) and temperature (80, 90, and 100 °C) were utilized in a constant microwave power and frequency of 1000 W and 28 kHz during ultrasound and microwave-assisted vacuum frying (USMVF) process. Ten different mathematical models were employed to describe dehydration kinetics of the fried edamame, and nonlinear regression analysis was used to determine model parameters. Concerning fitting performance, the most suitable model was the two-term model. Drying kinetics, effective moisture diffusivity (D_e), activation energy (E_a), and physical properties of fried samples were evaluated in this newly designed USMVF equipment using different ultrasound power to the studied temperature range. By increasing the US power level, the calculated D_e increased from 1.947 × 10⁻⁹ to 4.742 × 10⁻⁹ m²/s. The results have revealed that the E_a of this fried edamame decreased significantly with increasing the US power level. The USMVF process at every frying temperature increased the drying kinetics and D_e when compared to the non-USMVF process. The USMVF samples always gave lower oil content and water activity in contrast to the non-USMVF samples. The color and texture properties of fried edamame were significantly improved and higher the US power level in the USMVF produced a better progress. Vitamin C and chlorophyll retention of fried edamame was highest in US600MVF process.

Keywords:

• Edamame
• vacuum frying
• microwave-assisted vacuum frying
• ultrasound and microwave-assisted vacuum frying
• modeling
• effective moisture diffusivity
• activation energy

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We acknowledge the financial support provided to this work by National Natural Science Foundation Program of China (Contract No. 31671864), China Key Research Program (Contract No. 2016YFD0400704-5), National First-class Discipline Program of Food Science and Technology (No. JUFSTR20180205), Jiangsu Province Key Laboratory Project of Advanced Food Manufacturing Equipment and Technology (No. FMZ201803).