College of Food Science and Engineering, Ocean University of China, 5th Yushan Road, Qingdao 266003, China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Engineering and Technology Research Center of Food Additives, Beijing Higher Institution Engineering Research Center of Food Additives and Ingredients, Beijing Technology & Business University, Beijing 100048, China.
Molecules. 2019 Aug 2;24(15):2824. doi: 10.3390/molecules24152824.
Skim milk has a poor flavor due to the lack of fat. Finding ways to improve the flavor quality of skim milk has attracted the attention of more and more researchers. The purpose of this study was to create a skim milk product with good flavor by processing. Briefly, raw milk was treated by preheating at pasteurization (85 °C, 15 s) and ultra-high temperature (UHT) instantaneous sterilization (137-141 °C, 4 s). Subsequently, the sample was centrifuged to remove fat and obtain two kinds of skim milk, namely, PSM (skim milk obtained by preheating at 85 °C, 15 s) and USM (skim milk obtained by preheating at 137-141 °C, 4 s). The results showed that the intensity of the main sensory attributes (overall liking, milk aroma, etc.) and the concentrations of the key flavor compounds (2-heptanone, 2-nonanone, decanal, hexanoic acid, etc.) were significantly higher in the USM ( < 0.05) than that of the PSM and RSM (skim milk without preheating). Principal component analysis (PCA) with E-Nose (electronic nose) showed that the RSM had significant differences in the milk aroma compared with the PSM and USM. Furthermore, it was found that there were good relationships between volatile compounds and sensory attributes by partial least squares regression (PLSR) analysis. These findings provided insights into improving the flavor quality of skim milk by preheating treatment instead of any flavor additives.
脱脂奶因缺乏脂肪而味道不佳。寻找改善脱脂奶风味质量的方法引起了越来越多研究人员的关注。本研究的目的是通过加工生产具有良好风味的脱脂奶产品。简要地说，原料奶通过巴氏消毒（85°C，15s）和超高温瞬时灭菌（137-141°C，4s）进行预处理。随后，将样品离心以去除脂肪，得到两种脱脂奶，即 PSM（在 85°C，15s 下预热得到的脱脂奶）和 USM（在 137-141°C，4s 下预热得到的脱脂奶）。结果表明，USM（ < 0.05）的主要感官属性（总体喜好、奶香味等）强度和关键风味化合物（2-庚酮、2-壬酮、癸醛、己酸等）浓度明显高于 PSM 和 RSM（未经预热的脱脂奶）。电子鼻（E-Nose）的主成分分析（PCA）表明，与 PSM 和 USM 相比，RSM 的奶香味有显著差异。此外，通过偏最小二乘回归（PLSR）分析发现，挥发性化合物与感官属性之间存在良好的关系。这些发现为通过预热处理而不是任何风味添加剂来改善脱脂奶的风味质量提供了思路。
