Study On Processing Factors Of Pesticide Residues Of Five Common Preservatives In Orange And Orange Juice

Oranges are popular fruits food,for which are tasted pretty delicious and rich in nutrition.Oranges are widely planted in China,including Gansu,Hubei,Hunan,Sichuan,Guangxi,Guangdong,Jiangxi and Yunnan provinces.Besides fresh fruits,it can also be made into fruit juice,canned fruit,preserves and essential oils,which have great economic benefits.Because of seasonal and regional limitations,preservatives are often used to prolong the preservation time of oranges after harvest.Pesticide residue is one of the most important factor that affect the quality and safety of oranges and their products.In this paper,orange was selected as the research object to investigate the change of thiophanate-methyl and other four preservatives pesticide residues in fresh orange and orange juice processed by different methods.The dietary intake risk of fresh orange fruit and juice was assessed.To provide basis data for optimizing processing technology and dietary risk assessment.The main conclusions are as follows:First,the analytical method was established to determine five kinds of commonly used preservations(thiophanate-methyl,Thiabendazole,imazalil,prochloraz,pyraclostrobin)in Orange whole fruit,peel,pulp,juice.Samples were extracted using acetonitrile,using PSA for purification and detected by ultra-performance liquid chromatography-tandem mass spectrometry.The average recovery was 74.3%–112.5% with the relative standard deviation≤17.7% in the range of 0.01-10 mg kg-1 concentraiton levels.The method is simple to operate,having a good sensitivity.It is suitable for simultaneous determination of five preservatives in orang processed products.Second,the changes of five common preservatives of thiophanate methyl,thiabendazole,imidazole,prochloraz and pyraclostrobin in eight processing processes of orange juice were studied.Disclosed the processing factors of five kinds of preservatives in the whole process and each step.The results showed that the processing factors of the five preservatives were less than 1 in the whole process and each step of orange juice processing.This indicates that orange juice processing can effectively remove pesticide residues in fresh orange fruits.Comparing crushing squeezing.The pesticide residues of five preservatives in orange juice obtained by squeezing are lower.Third,we use NETMDI and NEDI models to assess the risk of dietary intake of fresh orange fruits and processed samples combined with the data of dietary consumption and average body weight of Chinese residents.The results showed that the risk of dietary intake of five preservatives of different ages and sexes was different in orange fresh fruit and orange juice using two evaluation models.Generally speaking,the risk of dietary intake in the younger group is higher than that in the older group,the female group is higher than that in the male group,but all of them are acceptable risks.In addition,the risk of dietary intake will be higher if the processing factors are not considered.