Drying of wolfberry fruit juice using low-intensity pulsed ultrasound. (April 2021)

• Record Type: Journal Article
• Authors: Qi, Yaru; Yu, Fen; Wang, Xuecheng; Wan, Na; Yang, Ming; Wu, Zhenfeng; Li, Yuanhui
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 141(2021)
• Publication Date: 2021-04
• Subjects: Low-intensity pulsed ultrasound -- Vacuum drying -- Fruit juice -- Quality -- Drying characteristics; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2021.110953
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: In this study, the low-intensity pulsed ultrasound-assisted vacuum drying (LPUVD) was applied to improve the efficiency in drying wolfberry fruit juice with acceptable quality. The low-intensity ultrasound used was 0.7 W/cm 2, and the effects of pulsed ultrasound ratio and drying temperature on the drying kinetics and quality parameters (color, total flavonoid, total polyphenol content, DPPH radical scavenging activity and powder properties) were investigated and compared with continuous ultrasound-assisted vacuum drying (CUVD). It was shown that LPUVD offers an advantage over CUVD in quality retention, and LPUVD at 10 s: 10 s pulsed ultrasound ratio took only 30 min more than CUVD. Significant influence of pulsed ultrasound ratio on quality parameters was not observed ( p ≥ 0.05). The minimal quality loss was found in the sample dried at 50 °C whereas the maximum was found in the sample dried at 40 °C. Also, the drying methods and conditions showed no significant effects on the powder properties. Overall, the optimal drying conditions of LPUVD was found to be drying temperature of 50 °C and pulsed ultrasound ratio of 10 s: 10 s. The findings in current work demonstrate that LPUVD is a promising drying technique for wolfberry fruit juice. Highlights: Low-intensity pulsed ultrasound-assisted vacuum drying (LPUVD) was applied to dry juice. The effect of drying conditions on drying characteristics and product quality was investigated. 10 s: 10 s pulsed ultrasound ratio took only 30 min more than continuous ultrasound. LPUVD was in favor of retaining color, bioactive compounds and antioxidant capacity.