Parmar Pankaj, Singh Ashish Kumar, Meena Ganga Sahay, Borad Sanket, Raju P N
Department of Dairy Technology, Mansinhbhai Institute of Dairy and Food Technology, Mehsana, Gujarat India.
2Dairy Technology Division, ICAR-National Dairy Research Institute, Karnal, Haryana India.
J Food Sci Technol. 2018 Dec;55(12):4956-4963. doi: 10.1007/s13197-018-3431-4. Epub 2018 Sep 24.
The concentration of milk through evaporation is the most commonly employed unit operation for the production of a wide array of traditional and industrial dairy products. Major problems associated with thermal evaporation are a loss of aroma, flavor and color change. Ohmic heating (OH) has an immense potential for rapid and uniform heating of liquid, semi-solid and particulate foods, yielding microbiologically safe and high-quality product. The effect of ohmic heating on physico-chemical, rheological, sensorial and microbial properties during concentration of cow milk, buffalo milk and mixed milk (50:50) was studied and compared to conventional evaporation. OH significantly increased free fatty acids (FFA), apparent viscosity, hydroxymethylfurfural (HMF) content, instrumental color values i.e. redness () and yellowness () values. However, pH value and whiteness (*) of the concentrated milk decreased significantly. OH caused a drastic reduction in microbiological counts and treated milk can be kept for a longer period.
通过蒸发浓缩牛奶是生产各种传统和工业乳制品最常用的单元操作。与热蒸发相关的主要问题是香气损失、风味改变和颜色变化。欧姆加热（OH）在快速均匀加热液体、半固体和颗粒状食品方面具有巨大潜力，可生产出微生物安全且高质量的产品。研究了欧姆加热对牛奶、水牛奶和混合牛奶（50:50）浓缩过程中物理化学、流变学、感官和微生物特性的影响，并与传统蒸发进行了比较。欧姆加热显著增加了游离脂肪酸（FFA）、表观粘度、羟甲基糠醛（HMF）含量、仪器颜色值，即红色（）和黄色（）值。然而，浓缩牛奶的pH值和白度（*）显著降低。欧姆加热使微生物数量大幅减少，处理后的牛奶可以保存更长时间。
