title: Formation and elimination of pyrraline in the Maillard reaction in a saccharide-lysine model system.
abstract: BACKGROUND
  Pyrraline, a causative factor for various kinds of disease, is also used as a food contaminant to evaluate the formation of advanced glycation end-products (AGEs) in diet foods. In this study, model systems consisting of lysine and different saccharides were heated at different times, temperatures and initial molar ratios of saccharide to lysine under microwave heating conditions in order to investigate the formation of pyrraline.
  
  
  RESULTS
  Increase in initial molar ratio of saccharide to lysine could significantly promote the formation of pyrraline. Specifically, the pyrraline formation rate was influenced by the structure of saccharides involved in the reaction, and decreased in the following order: lactose > fructose > glucose > sucrose; the highest pyrraline was generated in lactose-lysine models. The maximum pyrraline was formed at 140 °C. Moreover, saccharides and lysine had different effects on the stability of pyrraline. Among the reactants, lysine was the major factor for the instability of pyrraline; a dipyrraline and a crosslink by pyrraline reacting with lysine could be formed.
  
  
  CONCLUSIONS
  Pyrraline formation by the saccharide-lysine model system was a dynamic reaction, consisting not only of the pyrraline formation, but also pyrraline elimination with some formation of crosslinks. © 2015 Society of Chemical Industry.
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.
authors.forename: Zhili
authors.initials: Z
authors.lastname: Liang
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.|Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.
authors.forename: Quanyi
authors.initials: Q
authors.lastname: Fu
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.|School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.|Department of Microbial Pathogenesis, Dental School, University of Maryland, Baltimore, MD, USA.
authors.forename: Zhenbo
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, China.|Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D006358:Hot Temperature; D008239:Lysine / Q000737:chemistry*; D015416:Maillard Reaction; D015394:Molecular Structure; D009646:Norleucine / Q000031:analogs & derivatives* / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*; D013997:Time Factors
chemical_list: D002241:Carbohydrates; D011758:Pyrroles; C059571:2-formyl-5-(hydroxymethyl)pyrrole-1-norleucine; D009646:Norleucine; D008239:Lysine
keywords: AGEs; microwave heating; model system; pyrraline; saccharide