Determination of malondialdehyde levels in meatballs obtained with different vegetable oils and cooking techniques using an in vitro gastrointestinal digestion model

Aim: This study aimed to evaluate the effects of vegetable oil type and cooking met-hod on malondialdehyde (MDA) levels and MDA bioaccessibility following in vitro gastrointestinal digestion in meatballs prepared with different vegetable oils. Material and Method: Meatballs were prepared using flaxseed, sunflower, or olive oil and cooked at 200 °C for 10 min in an air fryer or 20 min in a convection oven. The cooked samples were subjected to in vitro gastrointestinal digestion. MDA con-centrations before and after digestion were determined by HPLC, and MDA bioacces-sibility was calculated. Data were evaluated using two-way analysis of variance. Results: The highest post-digestion MDA concentration was observed in the oven-cooked flaxseed oil group (2.149 mg/100 g), whereas the lowest was detected in the air-fried olive oil group (0.191 mg/100 g). MDA bioaccessibility ranged from 174.9% to 183.2% in flaxseed oil, 142.3% to 165.6% in sunflower oil, and 31.8% to 44.4% in olive oil groups. Oil type significantly affected all MDA parameters. Cooking method had a significant main effect only on pre-digestion MDA (p=0.030), while the oil type × cooking method interaction was significant for MDA bioaccessibility (p=0.005). Conclusion: MDA formation and bioaccessibility were strongly associated with the fatty acid profile of the oil used. Flaxseed oil groups showed the highest, whereas olive oil groups showed the lowest MDA bioaccessibility. The findings indicate that oil type and cooking conditions should be considered together when developing meat products with modified fatty acid profiles.