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Title
Abstract
Introduction. The growing interest of consumers in purchasing minimally processed food that retains various bioactive ingredients has led to the need to investigate the impact of a new low-temperature preservation method on the quality characteristics of freshly pressed carrot juice (Nerac variety). The influence of plasma gas (air) generated in a Glide-arc reactor operating at atmospheric pressure on microbiological, physicochemical and structural changes in product samples was analyzed. Three groups of juices characterized by different exposure times to plasma (10, 20, 30 minutes) and untreated juice (control) were used for the study. The properties of the juices were assessed after 1, 2 and 3 days of storage in a refrigerator at 6 oC.
Results and conclusions. The test s showed that the juices exposed to plasma for 20 and 30 minutes were characterized by good, stable microbiological quality even after 3 days of refrigerated storage. Compared to the control sample, an increase in colloidal stability and, what is important, in the content of the extract, carotenoids and polyphenols was also observed in the products. An EDX analysis showed that the elemental compositions of the samples before and after plasma plating did not differ qualitatively, but there were slight quantitative differences. However, in all the samples of juice treated with cold plasma, a slight reduction in the brightness of the products and the chromaticity indices a* and b* was observed. In general, the results of the conducted research indicate that cold plasma treatment is a promising technique that can ensure better quality and greater colloidal stability during the processing of carrot juice, and the product treated in this way is characterized by better physicochemical properties and a greater amount of bioavailable nutrients.
Keywords
freshly pressed carrot juice, cold plasma, microbiological stability, nutritional values, colloidal stability, zeta potential