Determination of Antioxidant Activities of Rosehip Marmalade Added Kefir During Its Storage Process

Herein, the effect of rosehip marmalade addition to kefir on it antioxidant activities was investigated. Firstly, the production of kefir, having the supplements of semi-skimmed milk, powder kefir ferment, and rosehip marmalade at different proportions (0% (control), 10%, and 15%) was made. Kefirs were stored in the refrigerator on days 1, 7, 14 and 21 at 4 ± 1ºC. It has been determined that it has a highly significant (p<0.01) effect on TPC during the storage period. In addition, it has been determined that storage period has a significant (p<0.05) effect on Vitamin C, while has a insignificant (p>0.05) effect on DPPH. The rosehip marmalade kefirs and control kefirs vitamin C and total phenolic content values were in the range of 7.85-9.04 mg 100g-1 and 1931,18-2447,11 mg GAE L-1, respectively. On the other hand, the 2.2-diphenyl-1-picrylhydrazyl values of the samples were determined up to 67.85 μg ml-1 (EC50). With this research, it was concluded that the low Vitamin C content of kefir, which stands out in dairy products especially with its probiotic character, can be increased and it can be transformed into a fermented product with different sensory characteristics, both probiotic and prebiotic.