1-Penten-3-one with its fresh and pungent smell at a very low odor threshold of 0.94 μg/L water has been characterized as impact aroma compound in many foods, such as grapefruit, orange juice, black tea, olive oil, or tomatoes. While its importance to the fresh sensation of unstored not-from-concentrate (NFC) orange juice was recently confirmed by aroma recombinates, a total loss was determined already after 4 weeks in NFC orange juice stored at 0 °C. Until now, the degradation pathway of this compound has not been clarified. Systematic model studies resulted in the identification of 1-hydroxy-3-pentanone and 4-hydroxy-3,8-decanedione as degradation products as well as S-(3-oxopentyl)-l-cysteine in the presence of the amino acid. In orange juice samples, it was found that the elevated content of 1-hydroxy-3-pentanone indicates a thermal processing, while S-(3-oxopentyl)-l-cysteine showed a significant increase during cold storage. Additionally, both compounds were identified in other food samples, such as commercial orange juices, pickled olives and olive oil, fresh tomatoes and commercial tomato juice, and black tea.

中文翻译：

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非浓缩橙汁储存过程中关键香气化合物1-Penten-3-one的新降解途径

1-Penten-3-one具有新鲜和辛辣的气味，在0.94μg/ L的极低气味阈值下，水已成为许多食品（如葡萄柚，橙汁，红茶，橄榄油或番茄。尽管最近通过香气重组证实了其对于未储存的非浓缩橙汁的新鲜感觉的重要性，但在0°C储存的NFC橙汁中经过4周的测定，总损失已经确定。到目前为止，该化合物的降解途径尚未阐明。系统模型的研究导致了1-羟基-3-戊酮和4-羟基-3,8-癸烷二酮作为降解产物以及鉴定小号- （3-氧代戊基） -升-半胱氨酸在氨基酸的存在下。在橙汁样品中，发现1-羟基-3-戊酮的含量升高表明进行了热加工，而S-（3-氧代戊基）-1-半胱氨酸在冷藏过程中显示出明显的增加。此外，这两种化合物在其他食品样品中也得到了鉴定，例如商用橙汁，腌制的橄榄和橄榄油，新鲜番茄和商用番茄汁以及红茶。