Food and Tourism Faculty, Transilvania University of Brasov, Castelului 148, 500014 Brasov, Romania.
Faculty of Food Engineering, Banat's University of Agricultural Sciences and Veterinary Medicine "King Michael I of Romania" from Timisoara, Calea Aradului 119, 300641 Timisoara, Romania.
Molecules. 2020 Apr 4;25(7):1669. doi: 10.3390/molecules25071669.
In juice processing, ultrasound treatment has been tested as a potential alternative to conventional thermal methods to inactivate microorganisms and to enhance the nutritional status of juice. In this study, the impact of pasteurization and high-power ultrasound treatment on the quality of red grape juice was investigated in terms of the content of bioactive compounds such as phenolic compounds and l-ascorbic acid as well as regarding the microbiological and physicochemical properties. The grape juice was subjected to pasteurization (80 °C, 2 min) as well as to ultrasound treatment with an amplitude of 50 and 70% for 5 and 10 min. The results indicated the same level of total phenolic content for pasteurized and sonicated samples for 10 min with an amplitude of 70%, while the highest level of l-ascorbic acid was recorded for sonicated samples with an amplitude of 70% for 10 min. pH of sonicated samples decreased with amplitude and treatment time while total soluble solids and titratable acidity increased with amplitude and time. Moreover, the results indicated the usefulness of juice sonication to enhance the inactivation of microorganisms. Thus, the high-power ultrasound treatment might represent a viable technique to replace the conventional thermal treatment in grape juice processing.
在果汁加工中，超声处理已被测试为一种替代传统热方法的潜在方法，以灭活微生物并提高果汁的营养状况。在这项研究中，研究了巴氏杀菌和高功率超声处理对红葡萄汁质量的影响，包括酚类化合物和 l-抗坏血酸等生物活性化合物的含量以及微生物学和物理化学性质。将葡萄汁进行巴氏杀菌（80°C，2 分钟）以及超声处理，幅度分别为 50%和 70%，时间分别为 5 分钟和 10 分钟。结果表明，巴氏杀菌和 70%幅度超声处理 10 分钟的总酚含量相同，而 l-抗坏血酸的最高含量记录在 70%幅度超声处理 10 分钟的样品中。随着幅度和处理时间的增加，超声处理样品的 pH 值降低，而总可溶性固体和可滴定酸度随着幅度和时间的增加而增加。此外，结果表明，果汁超声处理可增强微生物的灭活。因此，高功率超声处理可能代表一种可行的技术，可以替代葡萄汁加工中的传统热处理。
