Oselu Stephen, Ebere Rebecca, Huka Guyo, Musalia Levi, Marete Eunice, Mathara Julius M, Mwobobia Florence, Arimi Joshua M
Department of Food Science, Meru University of Science and Technology, Meru, Kenya.
Department of Business Management, Meru University of Science and Technology, Meru, Kenya.
Heliyon. 2022 Nov 24;8(11):e11816. doi: 10.1016/j.heliyon.2022.e11816. eCollection 2022 Nov.
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.
截至2020年，肯尼亚是全球骆驼奶产量最高的国家，年产量达112.5万吨。尽管产量很高，但由于影响酸奶等产品增值的挑战，约50%的牛奶被浪费。骆驼奶酸奶的生产面临多重挑战，如质地差、结构脆弱，导致消费者接受度低。本研究旨在通过添加不同的稳定剂和氯化钙来改善骆驼奶酸奶的理化性质。酸奶样品采用3升骆驼奶、6%的糖、0.006%的发酵剂、玉米淀粉或变性淀粉以及氯化钙进行加工。稳定剂添加量为2%、2.5%和3%，氯化钙添加量为0.075%。牛奶在90℃下巴氏杀菌30分钟。在42±1℃下发酵6小时，酸奶储存在4℃。在发酵和储存过程中每小时监测总可滴定酸度、pH值和粘度，同时在冷藏储存1、7、14和21天时分析脱水收缩和持水能力。感官评价采用9分喜好量表对酸奶样品的总体可接受性、颜色、甜度和稠度进行评分。骆驼奶酸奶的总可滴定酸度随着发酵时间（0 - 6小时）和储存时间从1天到21天的增加而增加。pH值随着发酵时间（0 - 6小时）和储存时间从1天到21天的增加而降低。添加稳定剂增加了酸奶的粘度，在整个发酵和储存过程中，3%的玉米淀粉表现出最高的粘度。与变性淀粉相比，玉米淀粉对粘度的影响更大。氯化钙进一步提高了酸奶的粘度。与牛酸奶相比，添加稳定剂使脱水收缩减少了44%以上。在本研究中，当以2.5%的变性淀粉和0.075%的氯化钙添加稳定剂时，观察到粘度、脱水收缩和感官评价的最佳结果。
