Chen Jiaxin, Cao Chuanai, Yuan Dongxue, Xia Xiufang, Liu Qian, Kong Baohua
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China; Heilongjiang Green Food Science & Research Institute, Harbin, Heilongjiang 150028, China.
Food Chem. 2022 Aug 15;385:132700. doi: 10.1016/j.foodchem.2022.132700. Epub 2022 Mar 14.
Protein-lipid co-oxidation of whey protein isolate (WPI)-stabilized oil-in-water (O/W) emulsions with different ionic strengths (0, 100, 200, 300 and 400 mM) during storage were investigated. The results proved that changes in levels of adsorbed proteins induced by different ionic strengths could obviously affect the occurrence of protein-lipid co-oxidation. The level of oxidative stress was higher in adsorbed proteins extracted from control sample than in those extracted from emulsions with 300 or 400 mM ionic strengths. This was indicated by higher levels of N'-formyl-l-kynurenine (NFK) and carbonyl, lower fluorescence intensity and more serious unfolding of protein structure. Moreover, control sample showed the highest oxidative stability, which was indicated by lower levels of primary and secondary lipid oxidation products. These findings clearly illustrated that altered levels of adsorbed proteins induced by different ionic strengths play a crucial role in affecting protein-lipid co-oxidation in O/W emulsions.
研究了不同离子强度（0、100、200、300和400 mM）的乳清分离蛋白（WPI）稳定的水包油（O/W）乳液在储存期间的蛋白质-脂质共氧化情况。结果表明，不同离子强度引起的吸附蛋白水平变化会明显影响蛋白质-脂质共氧化的发生。从对照样品中提取的吸附蛋白的氧化应激水平高于从离子强度为300或400 mM的乳液中提取的吸附蛋白。这表现为N'-甲酰基-L-犬尿氨酸（NFK）和羰基水平较高、荧光强度较低以及蛋白质结构展开更严重。此外，对照样品表现出最高的氧化稳定性，这表现为一级和二级脂质氧化产物水平较低。这些发现清楚地表明，不同离子强度引起的吸附蛋白水平变化在影响O/W乳液中的蛋白质-脂质共氧化方面起着关键作用。
