Acetaldehyde

Soybean (Suyun 626) was purchased from Fengyuan Seed Co. (Lian Yungang City, China). Citral (98%), acetaldehyde (98%), methyl Heptenone (98%) were provided by J&K Chemical Ltd. (Shanghai, China). 3-hydroxycitronellal (95%) was prepared as method of Fkyerat and Tabacchi (16 ). Neral (containing 10% geranial and 90% neral) and geranial (containing 95% geranial and 5% neral) were prepared by separating commercial citral by Wolken et al. (6 (link)). All other chemicals (analytical grade) were purchased from Sinopharm Chemical Reagent Company (Shanghai, China). Deionized water was used in all the experiments.

The standards of tryptophan, and asparagine, acetaldehyde, acrolein, glyoxal and methylglyoxal, and nonafluoropentanoic acid were purchased from J&K Scientific Co, Ltd. (Beijing, China). harmane, norharman, N^ε-(carboxymethyl)lysine (CML), d₄-CML, N^ε-(carboxyethyl)lysine (CEL), and d₄-CEL were obtained by Santa Cruz Biotechnology Co. (Paso Robles, CA). Glucose and ¹³C₆-glucose, lysine and d₄-lysine, acrylamide and ¹³C₃-acrylamide were purchased from Sigma-Aldrich (Darmstadlt, Germany). Other amalytical grade chemicals were purchased from Sinopharm Chemical Reagent Co, Ltd. (Shanghai, China).