The off-flavor produced after thermal stabilization of mandarin (Citrus reticulata, Blanco) juices has limited the production of commercial juices. Methanethiol, a putrid-smelling sulfur volatile, has been identified for the first time in heated mandarin juices. Identification was achieved using a combination of capillary gas chromatography with two dissimilar columns and a dual sulfur-specific pulsed flame photometric detector and selected ion mass spectrometry detection. Static headspace solid-phase microextraction quantitation found that average odor activity values (OAVs) in heated juices were 25.5 for methanethiol compared to 10.8 for dimethyl sulfide. OAVs for methanethiol and dimethyl sulfide in fresh juices were ND (not detected) and 5.5, respectively. Hydrogen sulfide, carbonyl sulfide, carbon disulfide, and dimethyl disulfide were also identified and quantitated. Thermal decomposition studies of nonvolatile sulfur-containing potential precursors indicated that methionine was the major source of methanethiol. Additional heating studies with model juices demonstrated that ascorbic acid greatly accelerated the formation of methanethiol and methional, as well as dimethyl di and tri sulfides.

中文翻译：

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甲基硫醇，一种从普通果汁中热处理产生的异味：柑桔硫挥发物的研究。

柑桔汁（柑桔，布兰科）热稳定后产生的异味限制了商业汁液的生产。甲硫醇是一种腐臭味的硫挥发物，已在加热的普通话果汁中首次发现。结合使用毛细管气相色谱仪和两个不同的色谱柱以及双硫特异性脉冲火焰光度检测器和选定的离子质谱检测器进行鉴定。静态顶空固相微萃取定量分析发现，加热汁液中甲硫醇的平均气味活性值（OAVs）为25.5，而二甲基硫醚为10.8。新鲜果汁中甲硫醇和二甲硫的OAV分别为ND（未检测到）和5.5。硫化氢，羰基硫，二硫化碳，还鉴定和定量了二甲基二硫醚。非挥发性含硫潜在前体的热分解研究表明，蛋氨酸是甲硫醇的主要来源。使用模型果汁进行的其他加热研究表明，抗坏血酸极大地促进了甲硫醇和甲硫醇以及二甲基二硫醚和三硫化物的形成。