A novel formation pathway of Nε-(carboxyethyl)lysine from lactic acid during high temperature exposure in wheat sourdough bread and chemical model

Zhongfei Zhang; Weiwei Cheng; Xiaowen Wang; Mingfu Wang; Feng Chen; Ka-Wing Cheng

doi:10.1016/j.foodchem.2022.132942

A novel formation pathway of N^ε-(carboxyethyl)lysine from lactic acid during high temperature exposure in wheat sourdough bread and chemical model

Food Chem. 2022 Sep 15:388:132942. doi: 10.1016/j.foodchem.2022.132942. Epub 2022 Apr 11.

Authors

Zhongfei Zhang¹, Weiwei Cheng², Xiaowen Wang², Mingfu Wang², Feng Chen², Ka-Wing Cheng³

Affiliations

¹ Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Key Laboratory of Optoelectronic Devices and Systems, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China; Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen 518060, China.
² Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen 518060, China.
³ Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen 518060, China. Electronic address: kwcheng@szu.edu.cn.

PMID: 35447583
DOI: 10.1016/j.foodchem.2022.132942

Abstract

N^ε-(carboxymethyl)lysine (CML) and N^ε-(carboxyethyl)lysine (CEL) have been the most extensively studied advanced glycation end-products (AGEs) in foods. Their formation mechanism, especially the latter, has not been clearly delineated in fermented food. In this work, the relative contents of CEL and CML were evaluated in a sourdough-bread and a silica solid chemical model. Lactic acid (LA) content in the sourdough increased with fermentation time that was accompanied by an increase in CEL, but not CML content in the bread. The role of LA as a precursor for CEL was supported by a positive significant correlation between LA and CEL contents, and further analysis using isotope-labeled LA (LA-¹³C₃) revealed that the three carbon atoms of LA were incorporated into CEL. These findings for the first time indicate LA may function as a precursor to promote CEL formation in sourdough bread that merits further investigation.

Keywords: Formation pathway; Lactic acid; N(ε)-(carboxyethyl)lysine; Silica gel solid model; Sourdough bread.

MeSH terms

Bread / analysis
Glycation End Products, Advanced / analysis
Lactic Acid
Lysine* / analysis
Models, Chemical
Temperature
Triticum*

Substances

Glycation End Products, Advanced
Lactic Acid
Lysine