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

Abstract

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.

Effect of propolis extract addition on some physicochemical, microbiological, and sensory properties of kefir drinks

“…Öksüztepe et al (2020) reported the average fat content of 2.13% in fruit kefir drinks, and the fat contents of kefir drinks with mint juice at varying ratios (0%–4%) were between 2.82% and 2.87% (Gül, 2017). Demir (2020) reported the protein contents of kefir drinks with rosehip marmalade (0%–15%) between 1.96% and 2.82% while Dinkçi et al (2015) found the protein contents of kefir samples produced from a mixture of cow/oat milk between 1.53% and 3.48%. According to Turkish Fermented Dairy Products Communiqué (Turkish Food Codex (TFC), 2009), the milk fat content in kefir drinks should be less than 10%, and milk protein content of kefir and fermented milk products should be at least 2.7% on a weight basis.…”