Study On The Release Regulation And Mechanism Of Acrylamide In French Fries

Carbohydrate-rich food produces the higher levels of acrylamide during high-temperature processing.Acrylamide is neurotoxic,carcinogenic,and genotoxic.Due to potential security risks.therefore its generation mechanisms,bioavailability,metabolic toxicology and detection methods have become research hotspots in recent years.As the acrylamide in food matrix exhibited much lower toxicity than the pure acrylamide,this study aims to answer whether the free/bound state of acrylamide affect its release and bioavailability.HPLC-MS method was used to determine the content of acrylamide in French fries.A simple osmotic pressure-driven release diffusion model was established using a semi-permeable membrane to analyze the release and release rate of acrylamide in the real food and its digestives of simulated oral-gastric-intestinal digestion in vitro.The Caco-2 cell monolayer was used to simulate the intestinal mucosal barrier,and test the transport efficiency of acrylamide in French fries.This study is expected to provide a new perspective for assessing the bioavailability and toxicity of acrylamide in a real food and the impacts of digestion.The experiments and main results are summaried as below:1.For determination of acrylamide in French fries,the sample pretreatment and chromatographic analysis conditions were optimized as:Luna Omage C₁₈ 150×4.0 mm reversed phase column,detection wavelength 226 nm,flow rate 0.5 mL/min,elution gradient 0 to 5%acetonitrile in 15 min.The acrylamide peak was verified with mass spectrometry.The recovery rate was 77-87.6%,and the relative standard deviation was 3.7%.The measurement was accurate and reproducible,qualified as reliable quantitative method for the determination of acrylamide content in french fries.2.Separation of compositions with different molecular weight and the aggregates in aqueous extracts of French fries,using ultrafiltration or size exclusion chromatography coupled with dynamic laser light scattering detection（SEC-DLS）.The acrylamide content of each fraction was determined.The results showed that the acrylamide content of the French fries aqueous extract was 33%and 36%higher than the conventionally determined values after separation by the above two methods.3.Using semi-permeable membrane（dialysis tube）to establish an in vitro permeation model for determining the release rate of acrylamide in real food matrix and the digestion products.The results showed that the in vitro digestion slowed down the release of acrylamide in the French fries.Tomato paste inhibited the release of acrylamide in a dose-depandent manner.The homogenization with added emulsifiers and thickeners raised the viscosity but have no significant effect on the release of acrylamide.It is summaried that acrylamide exists in the dispersion of French fry aqueous extracts not only in the form of monomer,but also attached to the macromolecular biopolymers and aggregates,which in turn subsequently affect the release of acrylamide.4.The Caco-2 cell monolayer was employed to simulate intestinal mucosal barrier and investigate the cross-membrane transportation of acrylamide in French fries and their digestives.The results show that the apparent permeability coefficient of digested acrylamide decreases by0.28×10^-55 cm/s compared with the pure product,which indicates that simulated digestion increases the binding state of acrylamide and thus reduces its absorption rate.