Effect of ultrahigh temperature treatment on qualities of watermelon juice

Abstract

The watermelon juice was pasteurized by the ultrahigh temperature (UHT) treatment, and the qualities of the pasteurized juice were compared to screen the optimal UHT. The UHT of 120 and 135°C inactivated the microbial colonies and maintained the original color of the watermelon juice. The temperature of 120 and 135°C was also maintained the phenolic content by reducing the polyphenoloxidase activity. Moreover, the C9 aldehydes, especially the (E,Z)‐2,6‐nonadienal, presented the main aroma of the watermelon juice. The C9 aldehydes were formed as the results of the heat reduction and enzymatic metabolism. The temperature of 120 and 135°C reduced the alcohol dehydrogenase activity and well maintained the C9 aldehyde content of the watermelon juice. Hence, the temperature of 120°C of the UHT treatment was the optimal temperature for the production of the watermelon juice.

Effectiveness of pulsed light treatments assisted by mild heat on Saccharomyces cerevisiae inactivation in verjuice and evaluation of its quality during storage

“…The thermal treatment in juice processing is principally performed at 65 °C for 30 min, 77 °C for 1 min and 88 °C for 15 s (Miller & Silva, 2012). However, these treatments may lead to important chemical and physical changes that impair organoleptic properties, degrade nutrients and reduce the content of some bioactive compounds (Gómez, Welti-Chanes, & Alzamora, 2011;Tiwari, O'Donnell, & Cullen, 2009;Wang, Guo, Ma, Zhao, & Zhang, 2018). Therefore, the application of mild thermal treatments in combination with other technologies is sought by fruit juice processors in order to maintain the taste of the product while preserving their nutritional value (Vervoort et al, 2011).…”

Flavoring and extending the shelf life of cucumber juice with aroma compounds-rich herbal extracts at 4 °C through controlling chemical and microbial fluctuations

“…Packaging materials, temperature, storage time, and microbial load alter juice flavor ( Toldrá et al, 2020 ). The C9 compounds, especially (E,Z)-2.6-nonadienal, were responsible for the flavor of watermelon juice pasteurized at ultra-high temperatures ( Wang et al, 2018 ). The low odor threshold values of aldehydes compared to alcohols explain the important role of these compounds in characteristic flavor of cactus pear even in low concentrations.…”

Characterization and Comparison of Unfermented and Fermented Seed-Watermelon Juice

“…A total of 26 volatiles were assigned in the unfermented juice with hexanol, 1nonanol, 3-hexen-1-ol, trans,cis-2,6-nonadienal, trans-2nonenal, and nonanal as main components. Among the main components, the C9 alcohol and aldehyde, including 1nonanol, nonanal, trans,cis-2,6-nonadienal, and trans-2nonenal, formed the typical watermelon aroma [27,[31][32][33][34]; C5∼C7 alcohol and aldehyde usually show aroma of fruits; C10∼C13 alcohol and aldehyde show the aroma of the grease, dairy, and meat flavor [18].…”