Variations of volatile flavour compounds in finger citron (Citrus medica L. var. sarcodactylis) pickling process revealed by E-nose, HS-SPME-GC-MS and HS-GC-IMS

Xiaoai Chen; Haiqiang Chen; Jie Xiao; Jingyi Liu; Niang Tang; Aimei Zhou

doi:10.1016/j.foodres.2020.109717

Variations of volatile flavour compounds in finger citron (Citrus medica L. var. sarcodactylis) pickling process revealed by E-nose, HS-SPME-GC-MS and HS-GC-IMS

Food Res Int. 2020 Dec;138(Pt A):109717. doi: 10.1016/j.foodres.2020.109717. Epub 2020 Sep 24.

Authors

Xiaoai Chen¹, Haiqiang Chen¹, Jie Xiao¹, Jingyi Liu¹, Niang Tang¹, Aimei Zhou²

Affiliations

¹ Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
² Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou 510642, China; Guangdong Zhancui Food Co. Ltd., Chaozhou 515634, China; Huanong (Chaozhou) Food Research Institute Co. Ltd., Chaozhou 521021, China. Electronic address: zhouam@scau.edu.cn.

PMID: 33292962
DOI: 10.1016/j.foodres.2020.109717

Abstract

The pickled products of finger citron are famous in southern China for their unique taste and flavor. Although pickling process involves complex treatments including salting, desalting, sugaring, cooking and drying, extended shelf-life up to ten years after pickling can be achieved. In this study, the variations of volatile flavour components in the pickling process of finger citron were investigated by electronic nose (E-nose), headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). HS-SPME-GC-MS identified 85 substances, and HS-GC-IMS identified 81 substances, including terpenoids (21), aromatic hydrocarbons (11), alcohols (11), aldehydes (10), esters (7), phenols (6), acids (5), ethers (2), ketones (2), and other species (10). Linalool, limonene, (E)-3,7-dimethyl-1,3,6-octatriene, myrcene, 3-carene, β-pinene, α-pinene, terpinolene, 1-methyl-4-(1-methylethyl)-1,4-cyclohexadiene, α-terpinene, (S)-β-bisabolene, 1-isopropyl-2-methylbenzene and 1-methyl-4-(1-methylethenyl)-benzene were the stable substances at relatively high contents in finger citron at different pickling process. Salting and drying steps in the pickling process exerted greatest influence on the volatile components of finger citron. Salting promoted the generation of aldehydes, esters and acids, but led to the disappearance of alcohols, while drying promoted the generation of alcohols, phenols, aldehydes and acids at the expense of reduction in terpenoids. Our study revealed that the characteristic volatile compounds of finger citron pickled products was mainly formed by the biological reactions in the salting stage and thermal chemical transformations in the drying stage. This study also validated the suitability of E-nose combined with HS-SPME-GC-MS and HS-GC-IMS in tracking the changes of volatile components in finger citron during the pickling process.

Keywords: E-nose; Finger citron; HS-GC-IMS; HS-SPME-GC-MS; Pickling process; Volatile flavour.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

China
Citrus*
Electronic Nose
Gas Chromatography-Mass Spectrometry
Solid Phase Microextraction
Taste
Volatile Organic Compounds* / analysis

Substances

Volatile Organic Compounds