Formation of Advanced Glycation End Products during Frying of Potato Chips and Grilling of Beef Patties

Maillard reactions occur between reducing carbohydrates and mainly the N6-amino group of lysine and the guanidino function of arginine, leading ultimately to advanced glycation end products (AGEs). In the present work, we give a comprehensive analysis of 15 AGEs in commercial potato chips, reaching a total of almost 5 mg/100 g chips, and study the change of protein modifications during the frying of potato slices. Major lysine protein modifications were N6-carboxymethyl lysine, N6-carboxyethyl lysine, pyrraline, and N6-formyl lysine with contents of 500-950 μg/100 g chips. Additionally, we synthesized and detected N6-(2,3-dihydroxypropyl)lysine as a precursor probe for glyceraldehyde-derived AGEs and also quantitated 1-(5-amino-5-carboxy-pentyl)-3-(5-amino-5-carboxypentyl-amino) pyridinium salt (meta-DLP) and 2-ammonio-6-(3-oxidopyridinium-1-yl) hexanoate (OP-lysine) for the first time in a processed food matrix. These results were then transferred to the grilling of ribose-containing beef patties, where incubations of N2-t-Boc-lysine with labeled 1-13C- and 5-13C-ribose gave mechanistic insights into the AGE-related degradation of the pentose.