POSSIBILITIES TO PRODUCE YOGHURT FROM CAMEL MILK
By Selda Bulca
Faculty of Engineering Department of Food Engineering, University of Adnan Menderes, Turkey
Recently, the use of camel milk has increased as a new and alternative animal protein source for human consumption. However, there are some differences in the composition of camel milk compared with other kind of milk sources. One of these differences is that camel milk contains in high concentrations of antimicrobial agents such as lysozyme, lactoferrin, lacto-peroxidase and immunoglobulins. In many studies, it was reported that camel milk is not suitable for production of fermented milk, especially for yoghurt, due to the high concentration of antimicrobial substances.
Firstly, in this study, viscosity and pH changes in yoghurt produced from cow and camel milk were compared. For this purpose, both milks were heat treated at 80o C for 20 minutes. After 180 minutes, in cow’s milk the viscosity was 9891 mPa.s, and after 210 minutes it reached 25237 mPa.s. In contrast, the viscosity of cultured camel milk was determined as 1210 mPa.s after 90 minutes, while the viscosity remained around 1216 mPa.s after 380 minutes. As viscosity of cultured camel milk not increased, hence, suitability of the mixture of camel milk with different ratios of cow, sheep and goat milk for yoghurt production was investigated. After preparing of the milk mixtures, these were heat treated at 90°C for 15 minutes and cooled at 45°C. The starter culture (YC 350) was added and incubated at 42°C until the pH reached 4.7. During fermentation, every hour the pH, SH and viscosity were measured. According to the results of analysis in which the highest viscosity and the fastest pH drop, mixtures were chosen as optimum points for yoghurt production. In these optimum points yoghurt productions were performed and all the samples were stored for 1, 7, and 14 and 28 days at 4°C. During the storage, water holding capacity and syneresis analyses were conducted. According to the results, the optimum mixture was determined at 80%:20% cow milk: camel milk mixture. However, after 4 weeks of storage it was concluded that an increase in the syneresis and a decrease in water holding capacity (%) were found for yoghurt obtained from 80%:20% cow-camel milk mixture.