Investigation of in vitro gastrointestinal system bioaccessibility of advanced glycation products in gluten-free foods

This study aimed to determine the glyoxal and methylglyoxal content of gluten-free products, and their gluten-containing variants (control products), and to examine their bioaccessibility in the in vitro gastrointestinal tract. For this purpose, glyoxal and methylglyoxal values of 44 gluten-free and 31 gluten-containing (control products) products were analyzed using HPLC before and after digestion. Additionally, 5 gluten-free products with the highest content of glyoxal and methylglyoxal before digestion (bread, biscuits, cookies, crackers, and breakfast cereals) were paired with healthy beverage alternatives (milk, fresh pomegranate juice, 100% pomegranate juice, fresh orange juice, 100% orange juice). The effects of these beverages on the glyoxal and methylglyoxal content of gluten-free foods were evaluated. Results showed a difference between the gluten-free and control groups in terms of glyoxal and methylglyoxal values before and after digestion (p<0.05). In all groups, post-digestion glyoxal and methylglyoxal values increased compared to pre-digestion values, and bioaccessibility values were above 100%. The post-digestion glyoxal and methylglyoxal values of the gluten-free bread and cracker group were higher than the control group products (p<0.05 for glyoxal value). According to the without beverage group, after in vitro digestion, glyoxal values decreased in the gluten-free breakfast cereal + 100% orange juice and gluten-free biscuits + fresh orange juice groups by 335±12 - 285±13 µg/100 g and 51±18-40± 18 µg/100 g (p<0.05). According to the without beverage values, the post-digestion methylglyoxal values decreased by 4172±188-3863±175 µg/100 gfor gluten-free crackers+milk, 74±5-40±2 µg/100 for gluten-free cookies+ fresh pomegranate juice, 149±5-127 ±2 µg/100 for gluten-free bread+100% pomegranate juice, 382±17 - 305±14 µg/100 g for gluten-free breakfast cereal+100% orange juice and 1778±80-1507±68 µg/100 g for gluten-free biscuits + fresh orange juice (p<0.05 ). Due to the potential health risks of gluten-free products, product formulations and technology should be re-evaluated. In this study, it was also found that health drinks reduce AGE levels. Therefore, the pattern of healthy beverages and gluten-free products should be considered while planning the gluten-free diet, and their impact on clinical outcomes should be evaluated.