Impact of starter culture on curd manufacture –one of the most commonly consumedfermented milk products of Sri Lanka

Abstract: Curd is a popular type of fermented milk product in Sri Lanka. In commercial curd manufactories, freeze-dried starter cultures are used, whereas small scale curd manufactories make curd in the traditional way using curd from previous days as a starter. Curd can be made from buffalo milk or cow’s milk, where buffalo milk is more common. The amount of fat is higher in the buffalo curd compared with the cow curd. However, not much is known about the impact of the processing steps and health benefits of this product. This study was carried out in March - May 2019 in the middle of the country Sri Lanka at the University of Peradeniya. The aim of the study was to inves-tigate the effect of different starter cultures on the final product of curd made of buffalo milk, with respect to pH, syneresis and sensory aspects. Compari-son was done between three starters cultures: Pre-Made Buffalo Curd (PMBC), Pre-made Cow Curd (PMCC) and commercially available Chr Han-sen R-704 freeze-dried starter culture (CHR-704). All curd samples with different starter cultures showed gradual reduction of pH during three days of measurements with only small difference between the products. The highest reduction, 34%, was observed for curd with CHR-704 whereas curd with PMCC showed the lowest pH reduction, 31%. During the three days of observation, the syneresis in the curd decreased. Lowest syneresis, 3.86% was observed in curd with PMBC. Highest syneresis, 3.93% was observed in curd with CHR-704. The sensory aspects of the curd i.e. flavour, texture, odour, colour and overall acceptability were evaluated by 31 members of a sensory panel. Regarding flavor and color, the most preferred curds were curd with CHR-704 and PMCC, respectively. Curd with PMCC was the most preferred one, regarding odour and texture. For the overall ac-ceptability, 36% of evaluators preferred curd with PMCC whereas curd with CHR-704 was least preferred.