Abstract:In this study, high performance liquid chromatography-mass spectrometry (HPLC-MS) was used to establish a simple and stable method in detecting Nε-(carboxymethyl) lysine (CML) in foods; a quantitative determination of the CML content in four common -types of food in China (liquid foods, instant powders, seasonings, solid or semi-solid foods) was carried out. The optimal mobile phase composition for HPLC-MS was 30% methanol, and the analysis time and retention time for CML were 6 min and 3.7 ± 0.1 min, respectively. The CML levels in the foods were as follows: –bound form and free form in liquid foods were 2.72 ~ 5.18 ?g /mL food and 0.05 ~ 1.78 ?g /mL food; bound form and free form in instant powders were 0.84~63.00 ?g /g food and 0.73 ~ 14.37 ?g /g food; bound form and free form in seasonings–were 0.86 ~ 42.80 ?g /mL(g) food and 7.69 ~ 821.02 ?g /mL(g) food; bound form and free form in solid or semi-solid foods–were 0.63 ~ 61.22 ?g /g food and 0.24 ~ 9.29 ?g /g food. The highest CML content was found in dark soy sauce (bound form: 0.97 ± 0.11 ?g /mL food; free form: 796.35 ± 24.67 ?g /mL food), and the lowest CML content was observed in quick-frozen steamed buns (bound form: 0.66 ± 0.03 ?g/g food, free form: 0.42 ± 0.02 ?g /g food).
