Hedegaard R V, Kristensen D, Nielsen J H, Frøst M B, Ostdal H, Hermansen J E, Kröger-Ohlsen M, Skibsted L H
Food Chemistry, Department of Food Science, The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
J Dairy Sci. 2006 Feb;89(2):495-504. doi: 10.3168/jds.S0022-0302(06)72112-9.
Oxidation in 3 types of bovine milk with different fatty acid profiles obtained through manipulation of feed was evaluated by analytical methods quantifying the content of potential antioxidants, the tendency of formation of free radicals, and the accumulation of primary and secondary oxidation products. The milk samples were evaluated in parallel by descriptive sensory analysis by a trained panel, and the correlation between the chemical analysis and the descriptive sensory analysis was evaluated. The fatty acid composition of the 3 types of milk was found to influence the oxidative and lipolytic changes occurring in the milk during chill storage for 4 d. Sensory analysis and chemical analysis showed high correlation between the typical descriptors for oxidation such as cardboard, metallic taste, and boiled milk and specific chemical markers for oxidation such as hexanal. Notably, primary oxidation products (i.e., lipid hydroperoxides) and even the tendency of formation of radicals as measured by electron spin resonance spectroscopy were also highly correlated to the sensory descriptors for oxidation. Electron spin resonance spectroscopy should accordingly be further explored as a routine method for detection of early events in lipid oxidation in milk to predict shelf-life.
通过分析方法对经饲料调控获得的3种具有不同脂肪酸谱的牛乳中的氧化情况进行了评估，这些方法用于量化潜在抗氧化剂的含量、自由基形成的趋势以及一级和二级氧化产物的积累。由经过培训的专业小组通过描述性感官分析对牛奶样品进行平行评估，并评估化学分析与描述性感官分析之间的相关性。发现这3种牛奶的脂肪酸组成会影响牛奶在4天冷藏储存期间发生的氧化和脂解变化。感官分析和化学分析表明，氧化的典型描述词如纸板味、金属味和煮过的牛奶味与氧化的特定化学标志物如己醛之间具有高度相关性。值得注意的是，一级氧化产物（即脂质氢过氧化物），甚至通过电子自旋共振光谱法测得的自由基形成趋势也与氧化的感官描述词高度相关。因此，应进一步探索将电子自旋共振光谱法作为检测牛奶脂质氧化早期事件以预测保质期的常规方法。
