Effects of sunflower honey on the physicochemical, microbiological and sensory characteristics in set type yoghurt during refrigerated storage

The primary purpose of this research was to monitor the influence of sunflower honey addition (2%, 4% and 6% w/v) to yoghurt milk on survival of the microbial flora of yoghurt and the physicochemical and sensory characteristics during refrigerated storage for 4weeks. The water activity decreased according to the addition of honey with higher concentrations in the storage period (4°C). At the end of fermentation, pH values of yoghurt samples ranged between 4.33 (without honey) and 4.52 (addition of honey with 6%). The highest water holding capacity, consistency and the lowest brightness values were determined in the groups produced with 6% honey addition. The water holding capacity and a* (redness) values of the honey incorporated yoghurt samples increased during storage. Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus values of the yoghurt with honey increased compared with the control group samples (P<0.01). Addition of honey to yoghurt milk has affected the vitality of the characteristics starters in the incubation and storage time of the yoghurt samples (P<0.01). Optimum sweetness was obtained with the samples containing 4% honey level.