Investigation Of Acrylamide Formation Mechanism, Content Distribution In Fried Foods And Its Rapid Detection Method

Acrylamide(AM) in food has been become a global problem to disserve food safety recently.Long-term exposure to AM may cause damage to the nervous system both in human being and animals at a certain extent,and AM is also considered as a potential genetic and reproductive toxin with mutagenic and carcinogenic properties in experimental mammalians.In order to guide daily cooking and reduce the damage to health,the study of the formation mechanism of AM in foods,especially for those fried foods,are becoming more important to people.In this dissertation,both of native and overseas foods were taken as samples to reveal the formation mechanism and content of AM in foods using gas chromatography-solid phase microextraction (GC-SPME) method.Meanwhile,a rapid dermination method of AM was developed.This dissertation includes four chapters:In chapterâ… ,the development,mechanisms,toxicity and the research progress of AM in fried food was introduced.In addition,the determination methods were presented.In chapterâ…¡,a method for quantitative analysis of AM was developed using SPME.In this method,samples were defatted with n-hexane,extracted with aqueous solution of sodium chloride(NaCl),derivated with potassium bromate(KBrO₃) and potassium bromide(KBr),then extracted by SPME prior to a GC equipped with an electron capture detector.The optimized SPME experimental procedures to extract AM derivative in water solutions were found to be:a 75μm carboxen/polydimethylsiloxane (CAR-PDMS) coated fiber,extraction time of 30 min at room temperature and analyte desorption at 225℃for 3 min.An analytical working curve was constructed and found to be linear over 1.0 to 8000μg/kg AM with a limit of detection of 0.1μg/kg.The relative standard deviation was 4.02%(n=5).The proposed method was successfully used for the analysis of trace AM in foodstuffs.In chapterâ…¢,fried potatoes,pachyrhizus and flour were selected as typical examples for the investigation of the formation and elimination/degradation of AM. Experimental parameters including the fried temperature,fried time,content of water in the samples and the concentrations of various components were studied.The experimental results indicated that higher temperature(200℃) combining with a longer fried time reduced the generation of AM,due to elimination/degradation processes.The content of water in the sample was an important factor that affects the formation of AM,since water accelerated the formation of AM,but,simultaneously, it took roles as a reactant,solvent and transferring carrier of other reactants in Maillard reaction.The optimum water content was 12%to 18%of the mass of primal food.A certain concentration of asparagines or monosaccharides(in particular, fructose and also glucose and glyceraldehyde) was found to increase the net content of AM.Components in a protein-rich food strongly reduced the AM generation,which was probably caused by the competing reactions and/or covalently binding in the AM formation.In chapterâ…£,a rapid fluorescence determination method for AM in fried food was introduced.AM reacted with hypochlorite at pH 8.67 to give a complex with amine group.The product was then reacted with fluorescamine to generate a fluorescent compound.The compound excitated at 385 nm and the maximum emission wavelength was at 480 nm.It presented a good linear correlation between the concentration and the fluorescence intensity for AM.This method was successfully applied in rapid determination of AM with simple operation and less time-consuming.