Effect of methylglyoxal on the alteration in structure and digestibility of α‐lactalbumin, and the formation of advanced glycation end products under simulated thermal processing. Issue 4 (28th February 2021)

• Record Type: Journal Article
• Authors: Wu, Yuekun; Dong, Lu; Wu, Yajing; Wu, Dongyan; Zhang, Yan; Wang, Shuo
• Is Part Of: Food science & nutrition. Volume 9:Issue 4(2021)
• Page Start: 2299
• Page End: 2307
• Publication Date: 2021-02-28
• Subjects: digestibility -- methylglyoxal -- protein‐bound advanced glycation end products -- structural modification -- thermal processing -- α‐Lactalbumin; Food industry and trade -- Periodicals; Food -- Periodicals; Nutrition -- Periodicals; 664
• DOI: 10.1002/fsn3.2211
• Languages: English
• ISSNs: 2048-7177

Abstract

Abstract: α‐Dicarbonyl compounds (α‐DCs) are a class of compounds generated during the thermal processing of food. Due to the high reactivity, α‐DCs were endowed with the ability to react with food components thus lowering nutrition value and even leading to a potential risk for food safety. In this study, methylglyoxal (MG), the most abundant α‐DCs, was selected to investigate the alteration effects on the structure and digestibility of α‐lactalbumin (αLA) under thermal processing (60–100°C). The results showed that the modification degree of αLA by MG increased with the rise of processing temperature, accompanied by the significant changes in molecular weight, intrinsic fluorescence, and secondary structures of αLA. High‐resolution mass spectrometry analysis identified that lysine (Lys) and arginine (Arg) are the modification sites, and N ε ‐(carboxyethyl)‐L‐lysine is the main modification type. Since the Lys and Arg are also the cleavage sites of trypsin, the digestibility of MG modified αLA (MG‐αLA) by trypsin correspondingly decreased with an increase of processing temperature. The reacted Lys and Arg residues, and the protein‐bound AGEs were quantified, and the contents were found to be highly dependent on the temperature. Abstract : Methylglyoxal (MG) can modify α‐lactalbumin (αLA) during the thermal processing of food (60–100°C). With the increase of temperature, the higher modification degree of αLA by MG, the more changes in spatial conformation and secondary structure of MG‐αLA. Modification sites and modification types of MG‐αLA were identified by HPLC‐MS/MS. The in vitro digestibility of MG‐αLA also decreased significantly with increasing temperature, accompanied by the more formation of protein‐bound advanced glycation end products.