Abstract

The present study was carried out in the milk processing unit at college of animal production Science and Technology, Sudan University of Science and Technology during January-May 2012. The effect of fortification with skim milk powder (0, 5 and 7%) to the camel’s milk on the quality of yoghurt during storage was investigated. Fresh camel’s milk was purchased from Alaas farm at Khartoum North. Nine litres of raw camel’s milk were divided into three portions. The first treatment was used as control. To the other two treatments 5 and 7% of skim milk powder was added to the camels milk respectively, then the milk in each treatment was heated in a water bath at 85°C for 30 min. Milk samples were cooled to 43°C and 2% of commercial yoghurt starter culture was added and packed into plastic cups (200 g capacity) in triplicates. The plastic containers were incubated at 39°C until coagulation occurred (16 h) thereafter samples from different treatments were stored at 4°C for 0, 5and 10 days. Yoghurt Samples were taken for chemical, microbiological and sensory analysis.The results indicated that yoghurt treated with 7% skim milk powder had the highest viscosity value (p≤0.01) during storage period. The control yoghurt had the highest pH value (p≤0.01) during storage period in comparison with other treatments. In this study no significant differences in chemical composition of the yoghurt from different treatments during storage were observed. The yoghurt sample treated with 7% skim milk powder was significantly higher (p≤0.05) in total bacterial count (7.70×10⁶ cfu/mL than the control yoghurt (5.29×10⁶ cfu/mL). No variations were observed in lactic acid bacteria count. Coliforms and E.coli bacteria were not detected in tested samples. The results indicated that yoghurt treated with 7% skim milk powder had the highest (p≤0.01) flavour. Also there was significant difference (p≤0.05) in overall acceptability in tested treatments. It is concluded that camel milk yoghurt showed high coagulation time and the addition of skim milk powder to camel milk improved some physical properties of the yoghurt.

Keywords:

Camel, chemical, microbiological, sensory, skim milk powder, yoghurt,

References

Competing interests

The authors have no competing interests.

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