Investigation of the advanced glycation end products precursors in dried fruits and nuts by HPLC using pre-column derivatization

Nuts and dried fruits are among the most popular foods consumed worldwide due to their many beneficial effects on health. Many harmful products, such as 1,2-dicarbonyl compounds, glyoxal (GO) or methylglyoxal (MGO), can be formed during thermal processing and long-term storage as precursors of advanced glycation end products (AGE) in foods. This study aimed to determine GO and MGO in nuts and dried fruits. In this study, 38 different raw and roasted nuts and 17 different dried fruits were purchased from various markets in Istanbul, Turkey. The contents of GO and MGO in these foods were determined by HPLC using 4-nitro-1,2-phenylenediamine as a pre-column derivatizing reagent. The determined contents of GO and MGO in the nuts ranged from 0.02 mg.kg(-1) to 8.77 mg.kg(-1) and from 0.04 mg.kg(-1) to 620 mg.kg(-1), respectively. Raw nuts contained lower levels of GO and MGO than processed nuts. The contents of GO and MGO in dried fruits ranged from 0.1 mg.kg(-1) to 6.55 mg.kg(-1) and from 1.10 mg.kg(-1) to 41.35 mg.kg(-1), respectively. The significantly highest MGO content was determined in sulfured dried apricots (19.96-41.35 mg.kg(-1)), which contained considerably more MGO than sun-dried apricots.