高铁肌红蛋白对腌腊鱼脂质氧化与挥发性风味的影响

为探究高铁肌红蛋白(MMb)对腌腊鱼品质的影响,实验在腌制草鱼肉中添加不同浓度MMb (0、 0.1、 0.2、0.4、0.8 mg/g)构建样品反应体系,基于羰基化合物、脂质含量、脂肪酸组成及挥发性风味物等指标,研究腌腊鱼传统加工中MMb促脂质氧化作用机制。结果显示,随着MMb添加浓度的升高,3种羰基化合物含量逐渐递增,且增幅存在“4-羟基己烯醛>4-羟基壬烯醛>丙二醛”的趋势。与对照组相比,添加0.8 mg/g MMb样品组总脂、甘油三酯和磷脂含量降幅最大(分别为18.95%、18.72%和31.83%),而游离脂肪酸含量呈完全相反趋势(增幅为6.74%)。添加MMb浓度越高,鱼肉样品中多不饱和脂肪酸(PUFA)越容易发生氧化降解,亚油酸和花生四烯酸尤为显著(相对含量分别下降12.37%和16.27%)。本实验共检出6大类41种挥发性风味成分,确定了戊醛等13种气味活性物质,除癸醛外所有气味活性物质均与PUFA相对含量呈显著负相关,表明MMb介导的脂质光氧化反应可能是传统腌腊鱼香气的主要形成机制。

Effects of metmyoglobin on lipid oxidation and volatile flavor of cured fish

The effect of methemoglobin (MMb) on the quality of cured fish were studied by adding different concentrations of MMb into the cured grass carp meat to construct the sample reaction system. Based on the carbonyl compounds, lipid content, fatty acid composition and volatile flavor compounds, the mechanism of MMb promoting lipid oxidation in traditional processing of cured grass carp was studied. As a result, the contents of three carbonyl compounds increased gradually, and the increasing trend was "4-hydroxyhexenal > 4-hydroxynonenal > malondialdehyde" with the increase of MMb concentration. Compared with the control group, the contents of total lipids, triglycerides and phospholipids in the 0.8 mg/g MMb group decreased the most (18.95%, 18.72% and 31.83%, respectively). However, the content of free fatty acids showed a completely opposite trend (increased by 6.74%). The higher the concentration of MMb, the easier the oxidative degradation of polyunsaturated fatty acids (PUFA) in fish samples, especially linoleic acid and arachidonic acid (the relative content decreased by 12.37% and 16.27%, respectively). Six categories and 41 kinds of volatile flavor components were detected, and 13 kinds of odor active compounds such as pentanal were identified. All the odor active compounds except decanal were significantly negatively correlated with the relative content of PUFA. It indicated that MMb-mediated lipid photooxidation may be the main mechanism of traditional cured fish aroma.