Selective Degradation Of Cyflumetofen In Apple Planting And Processing And Its Effect On Apple Quality

Cyflumetofen is a new type of chiral pesticide.It is mainly applied to apple and citrus.Its mechanism of action is novel.It has obvious effect on control of red spider,and it has no cross-resistance with the existing traditional acaricide.There is a very good application prospects for cyflumetofen.In the acute toxicity test of animals,the toxicity of enantiomers of cyflumetofen was quite different,and the toxicity of?-?-cyflumetofen was significantly greater than that of its?+?-cyflumetofen.Accurate risk assessment cannot be performed at the racemic level.Therefore,the study of cyflumetofen from the level of enantiomers has a very important guiding role in its rational use and safe production of agricultural products.In addition,when pesticides are used to prevent pests and diseases,they may not only pose food safety risks,but also may affect food quality.Therefore,studying the effect of cyflumetofen on the flavor quality of apple can provide a scientific basis for the safe and high-quality production of agricultural products.In this study,we focused on the selective degradation of cyflumetofen during apple planting and processing from the level of the enantiomers,and explored the fate of cyflumetofen on apple using UPC²-MS/MS.In addition,this study used electronic nose,electronic tongue,solid-phase microextraction-gas chromatography tandem mass spectrometry?SPME-GC-MS?and ultra-high performance liquid phase-time of flight mass spectrometry?UPLC-Q-Tof?to study the impact of cyflumetofen on the quality of apples.And initially screened for flavors and nutrients that are significantly affected by cyflumetofen.The main results of the study are as follows:1.Analytical tandem tandem mass spectrometry and QuEChERS were used for the separation and analysis of the cyflumetofen enantiomers.The optimal protocol for the apple multi-matrix scavenger was 150 mg anhydrous MgSO₄,50 mg C₁₈,50 mg PSA,and 10 mg Carb.A study on the distribution of cyflumetofen in apples was conducted.The residual amount of cyflumetofen in apple peel was the highest,followed by pomace and stalk,which could be due to the characteristics of various parts of apple.2.During the apple planting,the residual amount of cyflumetofen in apple gradually decreased with time,and its residual amount showed a near-negative exponential decreasing law.The degradation process conformed to the kinetic first-order degradation model.Under the conditions of high concentration and low concentration of cyflumetofen suspension spraying,the degradation trends of the two enantiomers of cyflumetofen in apples remained basically the same,the half-life of which was22.13-23.64 days,P>0.05,indicating that there was no significant selective degradation for cyflumetofen enantiomer during apple cultivation.3.During the typical processing of apple,the concentration of cyflumetofen was gradually reduced.During these processes,peeling has the most significant effect on the degradation of cyflumetofen.During the fermentation of cider,the enantioselective degradation of cyflumetofen was degraded obviously.However,during the processing of apple crisps,juice,and vinegar the degradation rate of the cyflumetofen enantiomers remained essentially the same.4.Using electronic nose and electronic tongue to analyze the difference in flavor quality,it was found that fenflufenac had an effect on the flavor of apple,and the difference was significant.Using SPME-GC-MS technology to analyze the volatile aroma compounds,it was found that cyflumetofen could reduce the content of volatile aroma substances in apples.The main affected compounds were ester compounds,of which the main aroma hexyl acetate was most affected.With the increase in the concentration of cyflumetofen suspension,the changing trend is more and more obvious.In addition,an unknown class of nitrogenous compounds was produced in apple after spraying cyflumetofen.UPLC-Q-TOF was used for food group analysis.The results of screening analysis showed that there was a significant difference in sugars and alcohols in apple after spraying cyflumetofen.