Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
Food Chem. 2013 Dec 1;141(3):2466-72. doi: 10.1016/j.foodchem.2013.05.049. Epub 2013 May 22.
Changes in lipids, lipoxygenase activity and fishy odour development in the skin of Nile tilapia (Oreochromis niloticus) during iced storage of 18 days were monitored. Triacylglycerol content of skin decreased with coincidental increases in free fatty acid, monoacylglycerol, diacylglycerol and phospholipid contents during storage (p<0.05). During iced storage, peroxide value increased at day 9 and subsequently decreased up to 18 days (p<0.05). Thiobarbituric acid reactive substances values and lipoxygenase activity increased throughout 18 days of iced storage (p<0.05). With increasing storage time, a progressive formation of hydroperoxide was found as evidenced by the increase in amplitude of peak at 3600-3200 cm(-1) in Fourier transform infrared spectra. Those changes indicated that lipid oxidation took place during iced storage. The increase in fishy odour of skin was observed as the storage time increased. The development of fishy odour in Nile tilapia skin during iced storage was mostly governed by lipid oxidation via autoxidation or induced by lipoxygenase. Thus, the extended storage time of whole fish resulted in the pronounced changes in lipids and the increased fishy odour in the skin.
在 18 天的冰藏过程中，监测了尼罗罗非鱼（Oreochromis niloticus）皮肤中脂质、脂氧合酶活性和鱼腥气味的变化。在贮藏过程中，三酰基甘油含量下降，同时游离脂肪酸、单酰基甘油、二酰基甘油和磷脂含量增加（p<0.05）。在冰藏期间，过氧化物值在第 9 天增加，随后在 18 天内下降（p<0.05）。在整个 18 天的冰藏过程中，硫代巴比妥酸反应物质值和脂氧合酶活性都增加了（p<0.05）。随着贮藏时间的增加，通过傅里叶变换红外光谱中 3600-3200cm(-1)处峰振幅的增加，发现了过氧化物的逐渐形成，表明发生了脂质氧化。这些变化表明在冰藏过程中发生了脂质氧化。随着贮藏时间的增加，皮肤的鱼腥气味增加。尼罗罗非鱼皮肤在冰藏过程中产生的鱼腥气味主要是通过自动氧化或脂氧合酶诱导的脂质氧化产生的。因此，整鱼的贮藏时间延长导致皮肤中脂质发生明显变化和鱼腥气味增加。
