Analysis And Application Study Of The Ethephon Residue In Fruits And Vegetables

Fruit and vegetable is the important source of vitamin,mineral and dietary fiber,which is indispensable to maintain human healthy body and supply nourishment.At present pests occurrence degree and spread speed are high in fruit and vegetable.For the sake of controlling diseases and insect pests,pursuing the output one-sidedly,the producer irrational use of inorganic fertilizer,pesticide and hormone in the production process.It causes the product quality decreased.Furthermore,eating this product which has high pesticide residue is easier to cause the normal physiology function disorder of human body and health danger.With the increasing of pesticide variety and application,the safety of edible agricultural products,especially pesticide residue problem attracts people's attention. The governments all around the world control residual pesticides in farm produce by establishing pesticide residue limits standard which quantity is more and more, requirement is more and more strict,control agrochemical to remain quantity.Ethephon is a plant growth regulator pesticide,which is mainly used in plant accelerate ripening,yield-increasing,preservation and the long distance transportation.In order to increase the yield and obtain more benefits,the phenomenon of overusing ethephon is comparatively severe in recent years.This makes people pays more attention to the ethephon residue in fruit and vegetable.The aim of this research is to establish a rapid and simple method for determination ethephon residue in food on the basis of optimizing determination parameters,then survey and analyze some fruit and vegetable which sell on the Baoding market of all year,and compare nutrition components of different artificial ripening and natural ripening tomatoes.That will supply scientific basis for safe and reasonable utilization of ethephon.In this test,we selected suitable pre-treatment conditions through headspace gas chromatography by using the Shimadzu GC-17 gas chromatograph:The favorite sample homogenate weight was 10g in the 20ml headspace bottle,addition of 60%KOH solution was 3ml and acetone was 1mL.Water bath temperature was 70℃,reaction time was 2h. Chromatography conditions were determined based on good separation,high sensitivity and wide linear range:detector:FID;GS-Q column:25m×0.32mm×0.25μm;carrier gas:high-purity nitrogen(99.999%),hydrogen flow rate:60mL/min,air flow rate: 50mL/min,trail flow rate:75mL/min;injector temperature:180℃,detector temperature: 230℃,programmed temperature:the initial temperature was 70℃(maintained for 2min), raised to 180℃with a rate of 25℃/min(maintained for 3min);split ratio:10:1.Calibration graphs were good linearity over the concentration ranges tested(0.02～10mg/kg,R=0.9999). The LOD of the standard solution were 0.01mg/L.The tomato recovery with standard addition was 78.5%～94.3%,RSD＜6.4%;the banana with standard addition was 82.7%～96.2%,RSD＜5.5%.With this method,comparisons between quality of artificial ripening and natural ripening tomatoes(bananas)were carried out.The investigation and analysis on some fruit and vegetable which sell in the Baoding market of all year was also discussed.The results showed as follows:1.Fruit ripening of tomato was stimulated by the ethephon-ripening treatment,and there was a positive correlation between ethephon smearing concentration and induced maturing.But fruit color and juice of high smearing concentration was comparatively poor. The effect of coating ethephon in the field is better than dipping ethephon after harvesting when they are compared.The highest ethephon residue was in the treatment of smearing ethephon after harvesting,it has reached 1.98mg/kg when dipping concentration was 4000mg/kg.However,the residue of artificial ripening in field and artificial ripening after harvesting were 2.29mg/kg,3.14mg/kg when treatment concentration was 6000mg/kg, which both exceeded MRL.Meanwhile,the contents of lycopene and vitaminC with two artificial ripening methods was lower than those in natural maturing,but the decrease range of artificial ripening after harvesting was very obvious,declined by 55.6%and 13.6% respectively.Compared with natural maturing,two artificial ripening methods appeared a little decreasing trend in sugar content,10.67%and 13.6%respectively,but there was no difference in two artificial ripening methods.There was no significant difference among three methods in the solube solid content and organic acid content.2.Fruit ripening of banana was stimulated by the ethephon-ripening treatment,and there was a positive correlation between ethephon smearing concentration and induced maturing.But the effect on accelerating ripening of low concentration was well:pericarp color and fruit firmness was moderate.Fruit surface was not damaged seriously.The ethephon residues of fruit with peel and fruit without peel at different artificial ripening concentrations were both higher than natural maturing.Moreover,ethephon residue in banana increased with the rise in the ethephon treatment concentration,which did not exceed MRL.But the residue of fruit with peel was 1.72mg/kg when treatment concentration was 4000mg/kg,which had already MRL.The residue of fruit without peel was lower than fruit with peel whether artificial ripening or not.3.Ethephon residue investigation of some fruits and vegetables in Baoding market: Seventeen varieties(seventy six samples)were examined,which included five vegetables and twelve fruits.Total detection rate was 64.47%,vegetable detection rate was 73.81%, fruit detection rate was 52.94%,and the residue would never exceed the maximn permited limit,apple-pear,kiwifruit and persimmon were not detected.The highest residue was tomato(0.60mg/kg).Ethephon residue of Ya-pear,peach and banana had gone beyond MRL of UN.Annual investigation of ethephon residue in tomatoes:The residue varied basically with season,which was lower in summer(0.01mg/kg),higher in winter (0.37mg/kg)and spring.These research results can offer a useful and reliable reference for future formulation of Chinese ethephon residue standard,and provide a fundamental basis for dose design research of relation between ethephon and human healthy.This paper has much practical value.