بررسي اثر فرآيند طي تهيه خيارشور بر ميزان باقي مانده قارچ كش متالاكسيل در خيار

چكيده انگليسي :

Effect of Processing Conditions on Metalaxyl Residue in Fermentative and Pasturised Pickles Vahide Noohi v noohi@ag iut ac ir Date of Submission 2010 10 25 Department of Food Science and Technology Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Javad Keramat keramat@cc iut ac ir Mohammad Shahediv shahedim@cc iut ac ir Abstract Food safety is an area of growing worldwide concern on account of its direct bearing on human health The presence of harmful pesticide residues in food has caused a great concern among the consumers Hence world over to tackle food safety issues organic farming is being propagated However due to several reasons diffusion and acceptance of this approach in developing countries has been very slow Therefore it is important in the transient phase that some pragmatic solution should be developed to tackle this situation of food safety Food processing treatments lead to a significant reduction of pesticide residues Metalaxyl is a systemic fungicide and is widely used for a variety of fruit and vegetable crops This research was carried out to determine the effect of fermentation and pasteurization on reducing of metalaxyl residue in cucumber pickles The hypothesis of the research emphasized that the pickling process would lead to reduction of metalaxyl residue in the product Cucumber samples were collected after four days of spraying by fungicide The size of cucumbers was suitable for pickling process Amount of metalaxyl residue was determined After washing which was more than MRL i e 2 31 ppm In order to study the effect of different proccesing temperatures on metalaxyl residue pasteurization of the pickles was perfomerd in four different temperatures 70 75 80 and 85 C In order to study the effect of fermentation on metalaxyl residue reduction cucumber pickles were filled in jars and thereafter maintained in ambient temperature Sampling was done 5 10 15 and 20 days after filling The buffering version of Quick Eeasy Cheap Effective Rugged Safe QuEChERS method was used for metalaxyl extraction The extraction method with ethylacetate in which the sample is blended with solvent and then purified by thin layer chromatography was compared with two versions of QuEChERS method in which DSPE is used for clean up Two compared versions were based on the original unbuffered method which was first published in 2003 and AOAC Official Method 2007 01 in which acetate is used for buffering As a result of this comparing buffering version of QuEChERS method was chosen for the sample extraction The results showed that pickleing pasteurization and fermentation reduced the metalaxyl residue to below 0 5mg kg MRL The residue of metalaxyl in cucumber pickle was reduced by 87 90 91 and 92 after pasteurization at 70 75 80 and 85 C repectively Storage of the samples for two weeks showed no metalaxyl residue left in the products In fermentative pickle after 5 days of storage amount of metalaxyl reduction was 84 3 and reached to 100 after 20 days of fermentation Several factors that might contribute to the metalaxyl reduction in cucumbers during the preparation of pasteurization pickles are brine acetic acid soaking and leakage of fungicide into brine the brine temperature that was added and the temperature at which pasteurization was done Brine soaking leakage of fungicide into brine and the acetic solution due to fermentative reactions were operative factors on reduction of metalaxyl residue in fermented pickles Keywords Metalaxyl Maximum residue limit Cucumber pickle Pasteurization Fermentation

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بررسي اثر فرآيند طي تهيه خيارشور بر ميزان باقي مانده قارچ كش متالاكسيل در خيار

حد بيشينه مانده آفت كش , پاستوريزاسيون , تخمير