The effect of ultrasonication on storage stability of freshly-squeezed carrot juice

In this study; it is aimed to determine the changes in some chemical and microbiological properties of sonicated carrot juice during refrigerator temperature for 12 days. Freshly squeezed carrot juice was subjected to constant frequency sonication at 20 °C for 10 minutes at 30 °, 40 ° and 50 ° C at 50 % and 100 % amplitude values. The total phenolics content, total flavonoids content and antioxidant activity increased with respect to the zero order reaction kinetics during the storage of sonicated fresh carrot juices at different amplitude and temperature values. When assessed for the total carotenoids content, it was observed that the quality of sonicated carrot juice was maintained more than the non ultrasonically applied sample. It was determined that β-carotene content increased during storage in all samples subjected to ultrasonication, but this increase was not statistically significant. It has been observed that the amplitude and temperature of the ultrasonics have no significant effect on pH and ˚Bx. When the color values were examined, it was observed that the L *, +a*, +b*, C* parameters decreased with the zero order reaction kinetics during storage, while the parameter h increased. The values of total aerobic mesophilic bacteria and enterobacter loads in sonicated samples were found to be low compared to the control sample. After applying ultrasonic at 50 % and 100 % amplitude values at 30 ° and 40 °C temperatures, the number of enterobacter in the samples was lower than the control sample. After ultrasonication at 50 ˚C, the number of enterobacter was not detected in the samples. KEY WORDS: Ultrasonication, Carrot Juice, Total Phenolics, Total Flavonoids, Antioxidant Activity, β-carotene, storage.