5 种脱色剂对粗鱼油挥发性风味物质及脂肪酸组成的影响

为探究凹凸棒土、硅藻土、活性炭、沸石及活性白土5?种脱色剂对粗鱼油挥发性风味物质及脂肪酸组成的影响，采用气相色谱仪和顶空固相微萃取-气相色谱-质谱联用仪，对脱色鱼油的挥发性风味物质及脂肪酸的相对含量进行测定分析，并结合感觉阈值确定该鱼油主体风味成分。结果表明，赋予鱼油腥味、脂肪香味、蜡香等主要风味的壬醛、己醛、2-壬酮，其相对含量经脱色后有明显降低，风味改善效果显著。脱色后，鱼油的饱和脂肪酸相对含量呈下降趋势，而不饱和脂肪酸的相对含量则有增加趋势；酸价与过氧化值变化差异较大，而碘值及皂化值则无明显变化。凹凸棒土和活性白土脱色效果最佳，但脱腥效果较硅藻土、活性炭和沸石差。本研究结果对改善鱼油脱色工艺及脱色剂选择和不良风味等方面有一定理论指导意义。

Volatile Flavor Compounds and Fatty Acid Profiles of Crude Fish Oil Decolorized with Five Decoloring Agents

This study was undertaken to evaluate the effect of five different decoloring agents (attapulgite, diatomite, activated carbon, zeolite and activated clay) on the volatile flavor compounds and fatty acid composition of crude fish oil was investigated. Gas chromatography (GC) and headspace solid-phase microetraction coupled with gas chromatography-mass spectrometry (GC-MS) were used to determine the volatile flavor compounds and fatty acid composition of decolorized fish oils. The main flavor components were identified by sensory thresholds. The results showed that the relative contents of nonanal, hexanal, and 2-nonyl ketone, which contributed to the fishy odor and the fatty and waxy aroma, significantly decreased after decolorization, thereby significantly improving the flavor of fish oil. The relative content of saturated fatty acids declined, whereas the relative content of unsaturated fatty acids increased. Acid value and peroxide value rather than iodine value and saponification value changed significantly. The decoloring effects of attapulgite and activated clay were good, while diatomite, activated carbon and zeolite had poor deodorizing effect. The results from the present study will be helpful for improving the decoloring process and the flavor of fish oil in the future.