The aim of this study is to determine the quality characteristics of kefir by developing different flavours in order to increase its consumption. Plum (10%) and molasses (7.5%) which are rich in phenolic contents are used to produce kefir in different flavours. Chemical analysis (pH, titratable acidity, dry matter and colour), microbial analysis (total microorganism, Lactobacillus spp, Lactococcus spp. and yeast counts), total antioxidant activity (by ORAC method), total amount of phenolic contents and sensorial properties of all kefir samples were carried out at the 1st, 7th and 14th days of storage. Consequently, the results of pH, titratable acidity and dry matter in the kefir samples were determined to change between the values 4.11-4.39; 0.22-0.30 and 11.9-17.02% respectively, during the storage. In the colour analysis, the redness colour parameter of the kefir sample produced using molasses was determined to be higher compared to the other kefir samples. At the first day of storage, the total antioxidant contents of the control group kefir, plum- added kefir and molasses-added kefir samples were determined as 13.30; 16.80 and 17.35 µmol ml-1; and the total phenolic contents as 945.70; 2535.8 and 2357.6 mg ml-1, respectively. Content of total microorganism in kefir samples varied between 8.91-9.80 log kob ml-1during the storage period. Lactobacillus spp. and Lactococcus spp. contents of kefir produced using molasses were determined to have the highest values with 9.11 and 9.91 log kob ml-1, respectively, at the first day. Yeast content of the plum kefir and the molasses kefir samples including sugar was detected to be higher than that of the controlled kefir sample. According to the results of the sensory analysis, the kefir produced with plum was approved the most by the panelists. As a result of this study, two alternative products with quite high total phenolic content and antioxidant activity were developed for consumers.

In this study, the effect of postharvest salicylic acid (2 mM), oxalic acid (5 mM), putrescine (2 mM) and calcium (4% CaCl2) applications on storage performance of Autumn Giant plum fruit were investigated. After applications, plum fruits were placed in modified atmosphere packaging (MAP) and stored for 40 days at 85-90% relative humidity conditions at 0.5±0.5°C. In order to determine the fruit quality characteristics after treatments, weight loss, soluble solids content, titratable acidity, fruit firmness, ascorbic acid, total flavonoids, total phenolics and total antioxidant content analysis were performed at 10 days’ intervals. According to the results, the effect of applications on weight loss was not significant. The maximum decrease in flesh firmness, titratable acid and ascorbic acid content during storage was determined in control fruits. Although fluctuations in the form of increase or decrease in biochemical compounds were generally observed, decreases occurred according to harvest value at the end of storage period. Considering all measurements and evaluations, it was determined that application of salicylic acid and putrescine had a more positive effect on preservation of fruit quality properties and biochemical content of Autumn Giant plum cultivar during storage than other applications.