Production and characterisation of camel milk yoghurt containing different types of stabilising agents

As at 2020, Kenya was the best performing camel milk producer globally, with an annual production of 1.125 million tonnes. Despite the high production, about 50% of milk is wasted due to challenges affecting value addition to products such as yoghurt. The production of camel milk yoghurt faces multiple challenges, such as poor texture and weak structure, resulting in poor consumer acceptability. This study aimed to improve the physicochemical properties of camel milk yoghurt by adding different stabilising agents and calcium chloride. Yoghurt samples were processed using 3 L of camel milk, 6% sugar, 0.006% starter cultures, corn starch or modified starch and calcium chloride. The stabilisers were added at 2, 2.5, and 3% and Calcium Chloride at 0.075%. The milk was pasteurised at 90 °C for 30 min. Fermentation was performed for 6 h at 42 ±1 °C, and yoghurt was stored at 4 °C. The total titratable acidity, pH and viscosity were monitored hourly during fermentation and storage, while syneresis and water holding capacity were analysed at 1, 7, 14 and 21 days of refrigerated storage. The sensory evaluation was done using the 9-point hedonic scale to rate yoghurt samples' overall acceptability, colour, sweetness and thickness. The TTA of camel milk yoghurt increased with increasing fermentation time (0–6 h) and storage time from 1 to 21 days. The pH decreased with increasing fermentation time (0–6 h) and storage time from 1 to 21 days. The addition of stabilisers increased the viscosity of the yoghurt, with 3% corn starch exhibiting the highest viscosity throughout the fermentation and storage time. Corn starch had a higher effect on viscosity compared to modified starch. Calcium chloride further amplified the viscosity of the yoghurt. The addition of stabilisers reduced syneresis by over 44% compared to bovine yoghurt. In this study, the best results of viscosity, syneresis and sensory evaluation were observed when stabilising agents were added at the rate of 2.5% modified starch and 0.075% Calcium chloride.