LAUSR

BACKGROUND Braised chicken is one of the well-known traditional processed meat products in China. However, there is little or no report on Nɛ -carboxymethyllysine (CML) and Nɛ -carboxyethyllysine (CEL) formation when chicken braising. Besides, braising under a long time and high-temperature process will result in water loss. But, the relationship between water loss and advanced glycation end products (AGEs) kinetics is limited. So, the purpose of this study was to investigate the relationship between water loss and kinetics of free and protein-bound CML and CEL in braised chicken under different braising conditions (60-100°C, 5-60 min). RESULTS It was found that the levels of free and protein-bound CML and CEL increased with heating time and temperature. The correlation coefficient (R2 ) was largest at zero-order reaction (free CML: R2  = 0.908-0.954, protein-bound CML: R2  = 0.901-0.958, free CEL: R2  = 0.952-0.973, protein-bound CEL: R2  = 0.959-0.965). The activation energy of the free CML was 44.158 ± 3.638 kJ mol-1 , the protein-bound CML was 40.041 ± 3.438 kJ mol-1 , the free CEL was 40.971 ± 0.334 kJ mol-1 , and the protein-bound CEL was 40.247 ± 0.553 kJ mol-1 . Furthermore, with the increase of braising time and temperature, the drip loss and cooking loss also got aggravated. A significant positive correlation between water loss and AGEs levels during braising was observed by Pearson's correlation analysis (P < 0.05). CONCLUSION We concluded that the levels of free and protein-bound CML and CEL during braising were different, but they all met zero-order reaction kinetics. Water loss was probably one of the main reasons why AGEs formation during chicken braising. This article is protected by copyright. All rights reserved.