Nielsen J H, Olsen C E, Jensen C, Skibsted L H
Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
J Dairy Res. 1996 Feb;63(1):159-67. doi: 10.1017/s0022029900031630.
In a dairy spread (800 g lipid/kg, 10 g salt/kg) based on 750 g milk fat/kg and 250 g rapeseed oil/kg fat in 15 g extruded catering packaging, there was a more significant accumulation of cholesterol oxidation products than in butter (minimum 800 g lipid/kg, 12 g salt/kg) in 10 g extruded catering packaging when stored at 4 or at 20 degrees C. There was a lag phase of 7 weeks in cholesterol oxidation in dairy spread stored at 4 degrees C, while no lag phase was observed for storage at 20 degrees C. Total concentrations of oxysterols were, however, very similar for dairy spread stored at 4 and 20 degrees C after 13 weeks storage (approximately 12 micrograms/g milk lipid); storage at -18 degrees C almost prevented cholesterol oxidation (approximately 4 micrograms/g milk lipid). For butter, cholesterol oxidation was less pronounced at 4 degrees C (<3 micrograms/g milk lipid) than at -18 degrees C (approximately 4 micrograms/g milk lipid) and 20 degrees C (approximately 7 micrograms/g milk lipid). 7-Ketocholesterol was the dominant oxidation product, with 1.3 and 5.7 micrograms/g milk lipid in butter and dairy spread respectively after 13 weeks storage at 4 degrees C.
在一个15克挤压式餐饮包装中、基于每千克含750克乳脂肪和250克菜籽油的乳制涂抹酱（每千克含800克脂质、10克盐）中，当在4摄氏度或20摄氏度储存时，相比于10克挤压式餐饮包装中的黄油（每千克至少含800克脂质、12克盐），胆固醇氧化产物的积累更为显著。在4摄氏度储存的乳制涂抹酱中，胆固醇氧化存在7周的滞后期，而在20摄氏度储存时未观察到滞后期。然而，在储存13周后，4摄氏度和20摄氏度储存的乳制涂抹酱中氧甾醇的总浓度非常相似（约12微克/克乳脂质）；在-18摄氏度储存几乎能防止胆固醇氧化（约4微克/克乳脂质）。对于黄油，4摄氏度时的胆固醇氧化（<3微克/克乳脂质）不如-18摄氏度（约4微克/克乳脂质）和20摄氏度（约7微克/克乳脂质）时明显。在4摄氏度储存13周后，7-酮胆固醇是主要的氧化产物，黄油和乳制涂抹酱中分别为1.3和5.7微克/克乳脂质。
