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The composition of the volatile fraction of yoghurts made from cows’, buffaloes’, ewes’ and goats’ milks was investigated during the 28 days of storage at 4 °C using solid‐phase microextraction technique (SPME) and gas chromatography coupled to mass spectrometry analysis (GC/MS). A total of 34 volatile compounds were identified in yoghurts during their storage at 4 °C, including aldehydes, ketones, alcohols, esters, acids, terpenes, hydrocarbons and sulphur compounds. In this study, acetaldehyde, diacetyl and acetoin, considered as the major compounds of yoghurt, were detected in all yoghurts.

The aim of the study was to determine whether thermosonication extends the shelf life of ayran, an acidic milk drink. The effect of thermosonication at different temperatures (60, 70 and 80 °C) and times (1, 3 and 5 min) on the physicochemical and microbiological characteristics, and sensorial properties of ayran during storage were investigated. According to the results, thermosonication applied at 60 °C decreased lower the bacteria counts, although the Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus counts decreased as the temperature and time increased. The yeast and mold levels in samples treated with thermosonication were <1 log CFU mL(-1) during storage period. The ayran samples had non-Newtonian behavior, and the consistency coefficients of the thermosonicated samples were significantly higher than that of the heat-treated samples. Regarding serum separation, the most effective thermosonication treatment was applied at 70 °C for 3 min. The sensory properties of the thermosonicated samples were better than the thermal-treated samples after storage.

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The purpose of this study was to enhance the color and sensory quality and β‐carotene content of yoghurt by addition of carrot juice (CJ). Yoghurt samples were produced using cow's milk with the addition of sugar (10%, w/v) and sugar‐free (control), 15% CJ, 15% CJ plus 10% sugar, 20% CJ and 20% CJ plus 10% sugar and stored at 4 ± 1C. The chemical composition was determined after the first day; however, viscosity, syneresis, titratable acidity, pH, yeast and mould counts, color measurements, β‐carotene contents and sensory qualities of yoghurt samples were determined after 1, 7, 14 and 21 days. The highest and lowest β‐carotene amounts were determined in CJ20 (130.39 μg/100 g) and the control (2.87 μg/100 g) samples, respectively, at 14 days of storage. Depending on the concentration of CJ, β‐carotene contents and color intensity values were high in the yoghurt samples with CJ. The yoghurt sample with 15% CJ and 10% sugar was the most favorable for all sensory attributes. Practical Application The purpose of this study is to enhance the color and sensory quality and β‐carotene content of yoghurt by addition of CJ. The addition of CJ improved the nutritional value of yoghurt in terms of β‐carotene. The increment of CJ ratio increased β‐carotene contents and color intensity values of yoghurts. Yoghurt sample with 15% CJ and 10% sugar was the most favorable by the panelists.