The use of low-heat skim milk powder (SMP) in natural cheese production offers significant industrial advantages. However, SMP takes a long time to undergo rennet-induced gelation and forms a soft gel, which makes it difficult to use in cheese production. In this study, we investigated whether dry-heat treatment of low-heat SMP contributes to improving rennet-induced gel properties. We found that dry-heat treatment (65 °C; relative humidity, 40%; 2–6 h) accelerated rennet coagulation time (RCT), increased gel strength, and improved the water-holding capacity of the gel. Dry-heat treatment resulted in lactosylation, an increase in hydrophobicity, and a decrease in the zeta potential of casein micelles. These changes possibly contributed to the improvement in rennet-induced gelation. Additionally, the dry-heat treatment likely affected the surface properties of casein micelles by altering their secondary structure. This study offers valuable insights into SMP applications, particularly in the production of natural cheese in the dairy industry.

中文翻译：

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低热脱脂奶粉的干热处理可改善凝乳酶诱导的凝胶化

在天然奶酪生产中使用低热脱脂奶粉 (SMP) 具有显着的工业优势。然而，SMP需要很长时间才能进行凝乳酶诱导的凝胶化并形成软凝胶，这使得其难以用于奶酪生产。在这项研究中，我们研究了低热 SMP 的干热处理是否有助于改善凝乳酶诱导的凝胶特性。我们发现干热处理（65℃；相对湿度，40%；2-6小时）加速了凝乳酶凝固时间（RCT），增加了凝胶强度，并提高了凝胶的持水能力。干热处理导致酪蛋白胶束的乳糖基化、疏水性增加和 zeta 电位降低。这些变化可能有助于改善凝乳酶诱导的凝胶化。此外，干热处理可能通过改变酪蛋白胶束的二级结构来影响其表面特性。这项研究为 SMP 应用提供了宝贵的见解，特别是在乳制品行业的天然奶酪生产中。