Valuation, Security and Food Analysis Laboratory, National Engineering School of Sfax, Sfax University, Sfax, Tunisia.
INRAE, STLO, Rennes, F-35000, France.
J Food Sci. 2021 Jan;86(1):103-111. doi: 10.1111/1750-3841.15550. Epub 2020 Dec 8.
In this study, three skimmed and one whole-fat spray-dried camel milk powders were produced and their characteristics were compared to those of bovine milk powders. The physicochemical analysis of the produced powders indicated that camel milk powders (whether skimmed or not) presented higher ash and whey protein contents as compared to those of bovine milk powders. Our results indicated that the investigated camel and bovine milk powders exhibited a high solubility index (>99%) with poor dispersibility and wettability indexes due to their small particles size (d ≤ 12 µm) and their narrow size distribution (span ≤ 2). In addition, although camel and bovine milk powders presented the same total fat content, lower free fat content was measured for camel milk powders. Besides, the whey protein nitrogen index and the SDS-PAGE electrophoresis underlined that camel and bovine milk proteins remained intact after drying with low denaturation extent. It is worth noticed that camel milk proteins were less denaturized due to the absence of the heat-sensitive β-lactoglobulin in camel milk. Moreover, the low denaturation extent participated in the enhancing of the foaming capacity and stability of camel and bovine milk powders. Finally, the calorimetric analysis showed that higher fat melting temperatures were recorded in whole-fat camel milk powder and in their anhydrous form as compared to those of bovine milk. PRACTICAL APPLICATION: Camel milk powder is an emerging non-bovine dairy product. Understanding its rehydration ability and evaluating the impact of spray drying on its protein quality are promising approaches to obtain high-quality camel milk powder with high reconstitution ability. Findings of this study indicated that spray drying is a suitable technique to produce highly soluble camel milk powders with low denaturation extent. These results will benefit the research and development department of food industry (especially those producing camel milk powder) as well as the direct consumers.
在这项研究中，制备了三种脱脂和一种全脂喷雾干燥骆驼乳粉，并将其特性与牛乳粉进行了比较。所制备的粉末的物理化学分析表明，与牛乳粉相比，骆驼乳粉（脱脂或全脂）的灰分和乳清蛋白含量更高。我们的结果表明，所研究的骆驼和牛乳粉具有高溶解度指数（>99%），但分散性和润湿性较差，这是由于其颗粒尺寸较小（d≤12μm）且粒径分布较窄（span≤2）。此外，尽管骆驼乳和牛乳粉的总脂肪含量相同，但骆驼乳粉的游离脂肪含量较低。此外，乳清蛋白氮指数和 SDS-PAGE 电泳表明，在干燥过程中，乳蛋白几乎没有变性，变性程度较低。值得注意的是，由于骆驼乳中缺乏热敏β-乳球蛋白，因此骆驼乳蛋白的变性程度较低。此外，低变性程度有助于提高骆驼乳和牛乳粉的泡沫稳定性。最后，量热分析表明，全脂骆驼乳粉及其无水形式的脂肪熔点温度高于牛乳粉。实际应用：骆驼乳粉是一种新兴的非牛乳乳制品。了解其复水能力并评估喷雾干燥对其蛋白质质量的影响，是获得具有高复水能力和高蛋白质质量的优质骆驼乳粉的有前途的方法。本研究的结果表明，喷雾干燥是一种生产低变性程度、高溶解性骆驼乳粉的合适技术。这些结果将使食品工业（特别是生产骆驼乳粉的企业）的研发部门和直接消费者受益。
