Effects Of Antioxidants On The Formation Of Monochloropropanol Esters And Carbonyl Compounds In Palm Oil During Heating

Palm oil is one of the largest vegetable oils in the world.Palm oil was used as frying oil in the food industry.Palm oil is susceptible to chloropropanol contamination.Chloropropanol esters are a group of hazards derived from food thermal processing.It includes 3-monochloropropane-1,2-diol esters(3-MCPD esters),2-monochloropropane-1,3-diol esters(2-MCPD esters),1,3-two chloro-2-alcohol ester,2,3-two chloro-2-alcohol ester.3-MCPD esters and 2-MCPD esters collectively referred to as monochloropropanediol esters(MCPD esters).Due to its high content and strong toxicity in food,MCPD esters was highly concerned by scholars.This article explored the effect of antioxidants on the formation of MCPD esters and carbonyl compounds during the heating treatment of palm oil.First,an analysis method was established for testing MCPD esters.Secondly,this study established palm oil-sodium chloride reaction model and palm oil-ferric chloride reaction model.And,this study was to investigate the impact of a variety of factors(temperature,time of processing,pH,the concentration of salt solution,the volume of solution and pH)on the formation of MCPD esters and carbonyl compounds in palm oil.The relationship between MCPD esters and oil oxidation,carbonyl compound formation was studied.Finally,adding different concentration of TBHQ,AP and PG to the palm oil-ferric chloride reaction model.And the concentration-inhibition rate relationship was determined.Kinetic models for the formation of MCPD esters in palm oil-ferric chloride system and kinetic models for the inhibition of MCPD esters in palm oil-ferric-TBHQ system were proposed.The main studies and results were summarized as follows:1.An analysis method was established for testing MCPD esters.Optimized the relevant parameters of sample preparation.It was proved to be an accurate method for the determination of 3-MCPD esters and 2-MCPD esters according to the validation results.The recovery range was 99.56-118.68%.The limit of quantification(LOQ)of 3-MCPD esters and 2-MCPD esters was achieved 0.34 mg/kg and 0.42 mg/kg.The limit of detection(LOD)of 3-MCPD esters and 2-MCPD esters was achieved 0.1 mg/kg and 0.15 mg/kg.These results indicate that the method for the detection of MCPD esters in oil has good stability.This method can be used in experimental research.2.This study established palm oil-sodium chloride reaction model and palm oil-ferric chloride reaction model.And,this article was to investigate the impact of a variety of factors(temperature,time of processing,the concentration of salt solution,the volume of solution and pH)on the formation of MCPD esters and carbonyl compounds in palm oil.The results are shown below:In the palm oil-sodium chloride reaction model,when the heating temperature was increased,the content of MCPD esters,MGO,and DA tend to decreased and then increased.The content of GO was decreased.When the heating time was extended,the content of 3-MCPD esters showed downward trend,and there was no significant difference in the content of 2-MCPD esters(p>0.05).The content of GO and MGO showed a trend of decreasing and then increasing and then decreasing.The content of DA showed a trend of increasing and then decreasing.When the heating time was 12 h,the maximum DA content was 1045.87 ?M/kg.When the concentration of the salt solution was increased,there was no significant difference in the content of 3-MCPD esters.The content of 2-MCPD esters,GO,MGO showed a downward trend.The content of DA showed an upward trend.When the volume of the salt solution was increased,there was no significant difference in the content of MCPD esters(p>0.05).The content of GO,MGO and DA showed a downward trend.When the pH of the salt solution was increased,there was no significant difference in the content of MCPD esters(p>0.05).The content of GO showed a trend of increasing and then decreasing.The content of MGO and DA showed a trend of decreasing,then increasing and finally decreasing.In the palm oil-ferric chloride reaction model,when the heating temperature is lower than 220?,the content of MCPD esters has no significant difference(p>0.05).When the heating temperature is higher than 220?,the content of MCPD esters increased significantly.The content of MGO and GO showed an upward trend.The content of DA showed a downward trend.When the heating time was extended,the content of MCPD esters increased and then decreased.When the heating time was 16 h,the content of 3-MCPD esters and 2-MCPD esters was the highest,1917.17 mg/kg and 147.78 mg/kg,respectively.The content of GO and MGO showed an upward trend.The content of DA showed a downward trend and then an upward trend.When the salt solution concentration is less than 2 mol/L,there is no significant difference in the MCPD esters content.When the salt solution concentration exceeds 2 mol/L,the MCPD esters content increased significantly.The content of GO showed an upward trend and then decreased.The content of MGO and DA showed an upward trend.When the volume of the salt solution was increased,there is no significant difference in the content of 3-MCPD esters(p>0.05).The content of 2-MCPD esters increased significantly.The content of GO and MGO showed a downward trend.The content of DA showed a trend of increasing and then decreasing.When the pH of the salt solution was increased,there is no significant difference in the content of 3-MCPD esters(p>0.05).The content of 2-MCPD esters showed a trend of decreasing and then increasing.The content is the lowest at 14.55 mg/kg.The content of GO and DA was decreased.The content of MGO is increased.The reaction condition has an influence on the correlation of MCPD esters with carbonyl compounds,oil oxidation.3.The palm oil-ferric chloride system was selected as the reaction model.This article explored the inhibitory effect of TBHQ,AP and PG on MCPD esters formation.This research explored the effect of TBHQ on the formation of carbonyl compounds.The effect of TBHQ on the formation of MCPD esters was studied from the perspective of kinetics.The results are shown below:When the amount of antioxidant was increased,the inhibition rate of TBHQ and PG on MCPD esters showed a trend of increasing and then decreasing.The inhibition rate of AP on MCPD esters showed a trend of rising and then unchanged.TBHQ has an inhibitory effect on the formation of GO and DA.Adding TBHQ to the palm oil-ferric chloride reaction model,a reaction kinetic model was constructed.Using SPSS to fit the experimental data.It is concluded that the power function model has the best fitting effect.The R2 values are all above 0.80,and the fitting degree is well.