Pre-drying strategies for French fries: Enhancing quality and reducing PAH4 migration

Abstract

French fries are widely consumed globally; however, their high oil content and the presence of lipophilic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), which are linked to carcinogenic and mutagenic effects, pose significant health concerns. This study investigated the effects of three pre-drying methods- hot air drying (HAD), vacuum drying (VD), and microwave drying (MD) on PAH4 migration and key quality parameters of French fries, including oil content, hardness, and microstructural changes. The stable isotope-labeled PAH4 (PAH4-d12) were employed to simulate the migration of PAH4 from frying oil to French fries. SEM and CLSM 3D imaging revealed that HAD and VD had a denser microstructure in the fries, reducing oil absorption and PAH4 migration, while MD caused structural damage, increasing porosity and PAH4 migration. The results demonstrated that HAD and VD significantly minimized PAH4 migration, resulting in a firmer French fry with reduced oil absorption and improved oil retention. Specifically, these methods significantly reduced the oil content in French fries by 16.00–37.54 % and increased their hardness by 37.10–91.05 %. In contrast, MD increased PAH4 migration due to structural degradation, including the formation of larger pores, which facilitated significantly higher oil absorption. This study demonstrates that pre-drying methods such as HAD and VD can effectively reduce PAH4 exposure, enhance food safety, and improve the textural properties of French fries, offering a practical approach for producing healthier fried products.