The Effect of Zivzik Pomegranate Juice on the Physico-chemical and Sensorial Properties of Kefir Produced by Conventional Method

Abstract

This research was carried out to investigate the synbiotic effects of various concentrations of Siirt Zivzik pomegranate juicy kefir at different times. In this study, sterile cow’s milk of 7 L (1.5% fatty), Zivzik pomegranate juice of 2 L and kefir grains of 100 g were used. Physio-chemical and sensorial analyses were conducted by conventional methods. The initial pH values of the samples were adjusted to 4.00 for the purpose of decontamination and increased slightly during the storage period. Depending on the storage period, the highest aw value was determined as 6.25% (0.973) on the zeroth day; whereas, the lowest aw value was determined in the sample in 50% concentration (0.949) on the 7 th day. The highest dry matter amount in the samples was found in the kefir with 50% concentration (10.9%) and it was observed that the most important parameter affecting the dry matter amount was the fruit amount added as additive. It was determined that depending on the increase of the concentrations with Zivzik pomegranate juice, color measurement values (Red-GreenBlue; RGB) decreased. As a result of the sensorial analyses, the lowest general liking values according to hedonic scale of the ready-to-drink kefir was found in 6.25% concentration (10.12) and its highest general liking values according to hedonic scale were found in 50% concentration (15.94). A statistically significant negative correlation was determined between aw (p <0.05) and color (p <0.01) with dry matter in the samples. As a result of this study, it was concluded that new products with high functional properties were obtained, the shelf life of kefir extended partly, and Zivzik pomegranate juice may have an effect increasing the consuming level of kefir. Furthermore, it was considered that Zivzik pomegranate juice would be a reference for the studies on development of the new products to be obtained by being adding into kefir and similar other products.