Study On The Determination Of Acrylamide And Reducing Measures In Chinese Traditional Fried Pastry

Acrylamide which was neurotoxicity and potential carcinogenicity formed mainly in high temperatures processed food containing large quantity of starch.Since the initial report at the Swedish National Food Administration and Stockholm University regarding the finding of acrylamide in a variety of fried and oven-baked foods,the formation mechanisms and the ways of mitigating the presence of this toxicant in heated foodstuffs have received increasing worldwide attention.In this research,we aimed to set up a method for rapid determination of acrylamide in Chinese traditional fried pastry.Furthermore,a Maillard reaction system consisting asparagine and glucose was employed to test the effect of reaction conditions and saccharides on formation of acrylamide and the influencing factors for the formation as well as the possible ways for the reduction of acrylamide in fried dough twist were summarized.The main results were as follows:Preparation of hemoglobin（Hb）biosensor was investigated.Hemoglobin biosensor passivation can be caused by the formation of a covalent by acrylamide with the-NH₂group of the N-terminal valine of hemoglobin.Based on this principle,the hemoglobin-biosensors were prepared by immobilizing multi-wall carbon nanotubes（MWCNTs）and Hb in chitosan film on the surface of glassy carbon electrodes and these were used for the detection of acrylamide in fried food.The optimum analysis conditions for determination of acrylamide in fried food by differential pulse voltammetry（DPV）was determined as follow:pulse increment 0.008 V,pulse amplitude 0.05 V,pulse width 0.1 V,pulse interval 0.1 s.The oxidative-reductive detector consisted of 10μg·cm^-22 MWCNTs and the supporting electrolyte were 0.1 mol/L PBS（pH7.4）and 0.1 mol/L NaCl and5×10^-33 mol/L potassium ferrocyanide.The linear range of the response was from 3.0×10^-8mol/L to 3.0×10^-77 mol/L and the detection limit was estimated as 1.2×10^-88 mol/L taking into account a signal-to-noise ratio of 3.The developed method was practical in the determination of acrylamide in fried foods,with the advantages of simplicity,rapidity,sensitivity and accuracy over the standard high-pressure liquid chromatography method（HPLC）.Maillard reaction system was employed to test the effect of reaction conditions and saccharides on formation of acrylamide.The results demonstrate that reaction temperature is a key factor for acrylamide formation.With the increase of heating temperature from120℃to 180℃,the acrylamide concentration increased.Whereas the concentration of acrylamide increases at first and then decreases at 200℃.At pH<8.0,acrylamide content increased with the increasing pH value,reaching the maximum at pH 8.0 whereas the acrylamide content decreased with the increase of pH.Thus it is a good way to control acrylamide formation by reducing pH values of the food systems.The content of acrylamide is maximum in the equivalent molar ration of glucose and asparagine,and glucose is much more important for acrylamide formation than asparagine.Addition of cyclodextrin,mannitol,sorbitol and erythritol eliminated the formed acrylamide,while addition of galactose,fructose and sucrose promoted its formation.In addition,there is positive correlation between inhibition rate of acrylamide and concentration of cyclodextrin.β-glucan had no significant effect on acrylamide content.The influencing factors for the formation as well as the possible ways for the reduction of acrylamide in fried dough twist were summarized.It was proved that acrylamide content in fried dough twist can be remarkably reduced through improving processing technology and adding of different additives such as phenol antioxidants,non-reducing saccharides and amino acids.The effect of fried temperature on acrylamide was great.With the increasing temperature,the content of acrylamide rised substantially,but when the temperature reached 200℃,the content of acrylamide declined.As the extension of frying time,the acrylamide levels increased slowly.The acrylamide levels was higher fried using palm oil than other oils,such as peanut oil,corn oil,soybean oil.Adding V_C and ferulic acid will decrease the levels of acrylamide but TBHQ will increase the levels of acrylamide.The suppressive effect of saccharides sized down with the best in front were cyclodextrin,mannitol,sorbitol,Erythritol.β-glucan had no significant effect on acrylamide content and adding of sucrose will increase the levels of acrylamide.Cysteine,acid,lysine,glycine could effectively reduce the content of acrylamide.Glycine showed the best suppressive effect when the concentration of amino acids under 0.2%and glutamic may be the best suppressive additive when the concentration of amino acids from0.3%to 0.5%.The maximum reduction effect of acrylamide was observed when the addition level of both amino acids was 0.5%.