Buettner A, Schieberle P
Deutsche Forschungsanstalt für Lebensmittelchemie and Institut für Lebensmittelchemie der Technischen Universität München, Lichtenbergstrasse 4, D-85748 Garching, Germany.
J Agric Food Chem. 2001 Aug;49(8):3881-4. doi: 10.1021/jf0104329.
A few odor-active epoxyaldehydes, formed during lipid peroxidation, have recently been reported as intense aroma compounds in foods. However, very little is known about their flavor properties in general. Syntheses of homologous trans-2,3-epoxyalkanals (C(6)-C(12)) and trans-4,5-epoxy-(E)-2-alkenals (C(7)-C(12)) followed by structural characterization using mass spectrometry (MS/EI; MS/CI) and (1)H NMR measurements were performed. An evaluation of their odor qualities and odor thresholds by gas chromatography-olfactometry revealed the following: within the trans-2,3-epoxyalkanals, the odor quality changed from grassy for the compounds with six and seven carbon atoms to citrus-like or soapy for aldehydes with eight and more carbon atoms. The odor thresholds lay in the range of 3-15 ng/L (in air) and were nearly identical within the series; however, a slight minimum was measured for trans-2,3-epoxyoctanal to trans-2,3-epoxydecanal. In the series of the trans-4,5-epoxyalk-(E)-2-enals the C(10) compound was characterized by the lowest odor threshold of 0.6-2.5 pg/L of air. However, all trans-4,5-epoxy-alk-(E)-2-enals smelled intensely metallic.
最近有报道称，脂质过氧化过程中形成的几种具有气味活性的环氧醛是食品中强烈的香气化合物。然而，总体而言，人们对它们的风味特性知之甚少。我们进行了同系物反式-2,3-环氧链烷醛（C(6)-C(12)）和反式-4,5-环氧-(E)-2-烯醛（C(7)-C(12)）的合成，随后使用质谱（MS/EI；MS/CI）和(1)H NMR测量进行结构表征。通过气相色谱-嗅觉测量法对它们的气味质量和气味阈值进行评估，结果如下：在反式-2,3-环氧链烷醛中，碳原子数为6和7的化合物气味质量为青草味，而碳原子数为8及以上的醛类气味质量变为类似柑橘或肥皂味。气味阈值在3-15 ng/L（空气中）范围内，且该系列内几乎相同；不过，反式-2,3-环氧辛醛到反式-2,3-环氧癸醛的气味阈值略有最低值。在反式-4,5-环氧-(E)-2-烯醛系列中，C(10)化合物的气味阈值最低，为0.6-2.5 pg/L空气。然而，所有反式-4,5-环氧-(E)-2-烯醛都有强烈的金属气味。
