Department of Food Science and Technology, Hebei Agricultural University, Baoding 071001, China.
Molecules. 2020 Mar 3;25(5):1129. doi: 10.3390/molecules25051129.
The volatile components of milks fermented using traditional starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotics (Lactobacillus lactis, Lactobacillus bifidus, Lactobacillus casei, and Lactobacillus plantarum) were investigated by means of gas chromatography-mass spectrometry (GC-MS) combined with simultaneous distillation extraction (SDE). A total of 53 volatile compounds were detected, being 10 aldehydes, 11 ketones, 10 acids, 11 hydrocarbons, 7 benzene derivatives, and 4 other compounds. The starter culture was found to significantly affect the composition of volatile components in the fermented milks. Ketones and hydrocarbons were the dominant compounds in milk before fermentation, while acids were dominant compounds in the fermented samples. Compared with probiotics, there was greater abundance of volatile components in fermented milks with traditional strains. The importance of each volatile compound was assessed on the basis of odor, thresholds, and odor activity values (OAVs). Of the volatile compounds, 31 of them were found to be odor-active compounds (OAV > 1). The component with the highest OAVs in most samples was (E,E)-2,4-decadienal. Heatmap analysis and principal component analysis were employed to characterize the volatile profiles of milks fermented by different starter cultures. The results could help to better understand the influence of starter cultures on the odor quality of milks.
采用气相色谱-质谱联用（GC-MS）结合同时蒸馏萃取（SDE）技术研究了传统发酵剂（嗜热链球菌和保加利亚乳杆菌）和益生菌（乳杆菌、双歧杆菌、干酪乳杆菌和植物乳杆菌）发酵乳中的挥发性成分。共检测到 53 种挥发性化合物，包括 10 种醛类、11 种酮类、10 种酸类、11 种烃类、7 种苯衍生物和 4 种其他化合物。发酵剂的使用对发酵乳中挥发性成分的组成有显著影响。发酵前，酮类和烃类是牛奶中的主要化合物，而发酵样品中的主要化合物是酸类。与益生菌相比，传统菌株发酵的牛奶中含有更多的挥发性成分。基于气味、阈值和气味活度值（OAV）评估了每种挥发性化合物的重要性。在挥发性化合物中，有 31 种被认为是具有气味活性的化合物（OAV>1）。在大多数样品中，OAV 最高的成分是（E，E）-2,4-癸二烯醛。采用热图分析和主成分分析对不同发酵剂发酵乳的挥发性图谱进行了表征。研究结果有助于更好地理解发酵剂对乳香味品质的影响。
