Investigation of the effects of salad and drinks given with different types of meat on glycation and lipid oxidation products by the in vitro gastrointestinal system simulation

Plant polyphenols have the potential to inhibit the formation of glycation and lipid oxidation products. This research aimed to study the effect of the salads and drinks given with different types of meat on the malondialdehyde, glyoxal and methylglyoxal levels by the in-vitro digestive system; the research was carried out at Istanbul Sabahattin Zaim University, in the R and D Laboratory in February 2021. The type of meat used during the research were veal steak, veal round, chicken breast, chicken leg with skin, turkey breast and sea bass. Drinks were freshly squeezed orange juice, 100% grape juice, red wine, hardaliye, salgam (fermented turnip juice), freshly squeezed pomegranate juice, ayran (yogurt drink) and cola. Salads included coban, red cabbage salad and Mediterranean salad. The meat was cooked on an electric grill and subjected to in-vitro digestive system, after digestion an analysis of the malondialdehyde, glyoxal and methylglyoxal levels were calculated using HPLC. In all types of meat, the malondialdehyde, glyoxal and methylglyoxal levels were found to be higher post digestion in comparision to pre-digestion; respectively 51.8% to 832.7%; 405.2% to 1273.6% and 63.3% to 1062.5%. The level of malondialdehyde in meat significantly decreased after digesting salgam, pomegranate juice, ayran, red wine and red cabbage salad (p<0,05), with Mediterrenean salad and hardaliye there was a decrease in the level in all meat but turkey breast (p<0,05). Orange juice decreased the level of malondialdehyde only in veal steak and sea bass, while grape juice and cola increased it in veal round (p<0.05). The methylglyoxal level generally increased in types of meat and drinks; however, with salads, these levels mostly decreased (p<0,05). Mediterranean salad and red cabbage salad decreased the glyoxal level by 53.3% to 78.8% in all meat types except veal steak. Red cabbage salad decreased methylglyoxal level by 24.9% in sea bass (p<0.05). In conclusion, drinks and salads have different effects on the levels of malondialdehyde, glyoxal and methylglyoxal in the gastrointestinal system, in general, drinks reduced the malondialdehyde levels, while salads reduce the glyoxal and methylglyoxal levels. Preventing the formation of glycation and lipid oxidation products during digestion in meat may contribute to reducing the risk of chronic disease. It appears to be necessary to carry out an in vivo study on whether other foods and drinks have an effect on lipid oxidation.