Effect of vacuum on microwave extraction of hawthorn fruit

Abstract

The paper considers the influence of vacuum on microwave extraction of hawthorn fruit and provides a comparative analysis of conventional infusion and microwave extraction methods. Experimental studies using various methods provided the values of the amount of isolated water-soluble substances relative to the feedstock during 5, 10, 15, 20, 25 and 30 minutes of extraction at the set mixture temperatures of 40°C, 60°C, and 80°C. It was found that at all the above temperatures, the effect of vacuum on microwave extraction positively affected the yield of water-soluble substances throughout the extraction process. At 40°C, the maximum value of the extracted substances was reached at the 25th minute of extraction, while the yield of water-soluble substances was 13.56% higher compared to traditional infusion and 10.74% higher compared to microwave extraction. The yields with vacuum microwave extraction method at mixture temperature of 60°C also proved to be higher than the values of the methods being compared. At the extraction temperature of 80°C, the microwave extraction and the vacuum microwave extraction methods have the same maximum valuable components yields significantly exceeding the indicators of traditional infusion. In addition, the vacuum effect contributed to extraction acceleration, allowing the maximum amount of water-soluble substances to be extracted 5 minutes earlier. The experimental studies confirmed the positive effect of vacuum on microwave extraction of hawthorn fruit, which is the reason for further research and the search for optimal parameters of the vacuum microwave extraction technology.