Effects Of Lipids And Their Oxidation On The Formation Of Harzard Compounds Derived From Maillard Reaction

Lipids and their oxidation may affect the formation of hazards compounds derived from Maillard reaction,such as acrylamide(AA),5-hydroxymethylfurfural(HMF),and advanced glycation end products(AGEs).The common AGEs includs N~ε-carboxymethyl-lysine(CML),N~ε-carboxyethyl-lysine(CEL)and pyrraline etc.Therefore,model systems were constructed to study the role of lipids and their oxidation on the formation of AA,HMF and AGEs(CML,CEL and pyralline).The effects of fatty acids,triglyceridesand preoxidized vegetable oil(olive oil,sunflower oil and flaxseed oil),on the formation of AA,HMF and CML,CEL and pyralline were studied.In order to discuss the possible involed mechanism their effects on the formation APs andα-dicarbonyl compounds was also discussed.In addition,the formation of AA,HMF and AGEs in oil in water(O/W)emulsion systems was discussed.The main results are as follows:(1)The addition of fatty acid and triglyceride decreased the formation of AA,but promoted the formation of HMF.The inhibition effects on AA formation was not dependent on the addition content of FA,while the promotion effects on HMF formation increased with the increase of FA unsaturation.The correlation analysis showed that the concentration of AA was negatively correlated with the concentration of HMF and 3-DG,and the correlation coefficients were r=-0.805(p<0.01)and r=-0.5811(p<0.01),respectively.The content of HMF was negatively correlated with the concentration of GO,MGO and DA,and the correlation coefficients were r=-0.856(p<0.01),r=-0.878(p<0.01)and r=-0.937(p<0.01),respectively.These results showed that lipids affect the formation of AA and HMF by influencing the formation ofα-dicarbonyl compounds.(2)The presence of fatty acid and triglyceride promoted the formation of CML,CEL and pyrraline.The promotion of CML and CEL was not related to the unsaturation of FA and the addition amount.While the formation of pyrraline increased with the increase of FA,and the promotion effects of FA on the pyrraline formation was stronger than that of TG.The correlation analysis showed that the concentration of CML was positively correlated with the concentration of GO(r=0.702,p<0.05).The concentration of CEL was positively correlated with the concentration of MGO(r=0.881,p<0.01).The concentration of pyrraline was positively correlated with the concentration of Fru-Lys(r=0.791,p<0.01).These results indicated that lipids can promote AGEs formation by influencing the formation of APs andα-dicarbonyl compounds.(3)There was significant interaction effect between heating time of vegetable oil and vegetable oil nature on the formation of AA and HMF.The content of AA in the modle system prepared with preoxidized oil decreased with the increse of heating time of oils.The influence of vegetable oil nature on the AA formation depended on the preheating time of oils.With the extension of heating time of vegetable oils,the content of HMF in the model system decreased and then increased.The content of HMF in the system prepared with flaxseed oil was the highest.The fatty acid composition changed with peroxidation degree of vegetable oils,which affected the formation of AA and HMF in model systems.The AA content in model systems was positively correlated with squalene content in vegetable oils,but negatively correlated with the campesterol content.It was suggested that squalene and campesterol can promote and inhibit the formation of AA,respectively.In addition,HMF content in model systems was positively correlated with the content of brassicasterol,campesterol content,β-tocopherol andγ-tocopherol,which indicated that these endogenous antioxidantsin vegetable oils might promote the formation of HMF in model system.(4)There was significant interaction between heating time and vegetable oil nature on the formation of CML,CEL and pyrraline.The CML content decreased with the increase of unsaturation of vegetable oils,and with the increase of heating time of vegetable oil,the CML content in the system prepared by pre-oxidized decreased and then keeped unchanged.With the increase of heating time of vegetable oil,the CEL content in the systems prepared with olive oil increased and then tended to be stable.However,with the increase of heating time of vegetable oil,the CEL content in the systems prepared with sunflower oil and flaxseed oil increasd and then decrease.the effect of heating time of vegetable oil on CEL content was greater than that of vegetable oil species.With the increase of heating time of vegetable oil,the content of pyrraline in the system prepared with flaxseed oil increased first and then decreased.However,the content of pyrraline in the system of olive oil and sunflower oil decreased first and then became stable.The CML formation was negatively correlated with the contents of brassicasterol,campesterol content,andβ-tocopherol,but positively correlated with the contents of squalene.The results showed that different types of antioxidants had different effects on the formation of CML in model systems.However,the CEL content was negatively correlated with the content ofγ-tocopherol.It is suggested thatγ-tocopherol may inhibit the formation of CEL in model systems.The content of pyrraline was positively correlated with brassicasterol,campesterol content,β-tocopherol andγ-tocopherol.It was suggested that these endogenous antioxidants may promote the formation of pyrraline.(5)The formation rule of different hazards conpounds derived from Maillard reactions is different in emulsion systems.The formation rule of AA in aqueous solution model systems and O/W emulsion system was similar,but the content of AA in aqueous solution system is lower than that in O/W emulsion system.The emulsion system has no significant effect on the formation and content of HMF.At 120℃and150℃,the formation rule of CML in aqueous solution model systems and O/W emulsion system is similar,.But at 180℃,it is differentand the formation of CEL also followed this rule.CML and CEL are easier to degrade in aqueous model systems than in emulsion system at 180℃.