Carbon module labeling approach combining with gas chromatography-olfactometry-mass spectrometry technology clarifies the formation mechanism of furan and thiophene derivatives: Ribose and cysteine as a classic case study
Huan Liu, Ruotong Nie, Xiangru Wei, Haonan Shi, Yumei Yu, Rong‐Mei Gao, Yinna Zhou, Zhenyu Wang, Dequan Zhang
Abstract
The carbon fragments of furan and thiophene derivatives in the cysteine-ribose reaction were detected by using the carbon module labeling technology. Based on the absorbance values, the Maillard reaction between cysteine and ribose continued during 0–60 min. The ribose fragments had a small contribution on the generation of 4-hydroxy-5-methyl-3(2H)-furanone (HMF), 2-methyl-3-furanthiol, and 2-furfurylthiol, where the ribose carbon skeleton was intact. The 2-methyl-3-furanthiol was produced via HMF from 2,3-enolization reaction in the cysteine-ribose reaction. The 3-thiophenethiol carbon atoms came mostly from cysteine and partly from ribose, which was first confirmed from both the cysteine Strecker degradation and Maillard reaction. The 5-methyl-2-thiophenecarboxaldehyde might originate from the Michael addition of mercaptoacetaldehyde and 2-butenal via acetaldehyde, in which acetaldehyde came mostly from the cysteine pyrolysis.