Yu Ying-Jie, Yang Sheng-Ping, Lin Ting, Qian Yun-Fang, Xie Jing, Hu Changli
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.
Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China.
Front Nutr. 2020 Sep 9;7:155. doi: 10.3389/fnut.2020.00155. eCollection 2020.
Lipid oxidation and water migration are important factors in the quality changes of aquatic products. This study investigated the relationship between water migration and lipid oxidation in salmon filets under four different storage conditions (control: 0°C; T1: 4°C; T2 and T3: two temperature fluctuation groups) by detecting thiobarbituric acid-reactive substances, changes of fatty acids, and volatile organic compounds (VOCs), and other quality indicators including redness, microorganism, total volatile basic nitrogen (TVB-N), and water-holding capacity (WHC) were also measured. The results of low-field nuclear magnetic resonance (LF-NMR) showed that more trapped water (T) turned to form free water (T) in groups suffering temperature fluctuations. A more significant decrease in fatty acids was found in T2 and T1 groups, especially oleic acid (C18:1n9c), linoleic acid (C18:2n6c), and palmitic acid (C16:0). The VOCs with off-flavors (1-penten-3-ol, 2-penten-1-ol, (Z)-, 1-octen-3-ol, hexanal) in the groups suffered from simulated cold chain interruptions increased faster than the other two groups during storage. T was negatively correlated ( < 0.05) with stearic acid (C18:0), 1-penten-3-ol, hexanal, and nonanal, whereas T was positively correlated with 1-penten-3-ol, hexanal, and heptanal. Therefore, the temperature fluctuation accelerated the loss of polyunsaturated fatty acids and the increase of unpleasant odors related to water migration.
脂质氧化和水分迁移是水产品品质变化的重要因素。本研究通过检测硫代巴比妥酸反应性物质、脂肪酸变化、挥发性有机化合物(VOCs),研究了四种不同储存条件(对照:0°C;T1:4°C;T2和T3:两个温度波动组)下鲑鱼片水分迁移与脂质氧化之间的关系,还测定了包括红度、微生物、总挥发性盐基氮(TVB-N)和持水能力(WHC)等其他品质指标。低场核磁共振(LF-NMR)结果表明,在温度波动组中,更多的束缚水(T21)转变为自由水(T22)。在T2和T1组中发现脂肪酸的下降更为显著,尤其是油酸(C18:1n9c)、亚油酸(C18:2n6c)和棕榈酸(C16:0)。在模拟冷链中断的组中,具有异味的挥发性有机化合物(1-戊烯-3-醇、2-戊烯-1-醇、(Z)-、1-辛烯-3-醇、己醛)在储存期间的增加速度比其他两组更快。T21与硬脂酸(C18:0)、1-戊烯-3-醇、己醛和壬醛呈负相关(P<0.05),而T22与1-戊烯-3-醇、己醛和庚醛呈正相关。因此,温度波动加速了多不饱和脂肪酸的损失以及与水分迁移相关的不愉快气味的增加。