الفهرس 
English coverOnly 14 pages are availabe for public view
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Abstract
Most countries, especially developed countries have regulations in place to control pesticides usage, but their residues are still detected in raw agricultural commodities and processed foods. The effects of food processing on pesticide residues reviewed extensively by researchers. The purpose of first and second part were to evaluate validation parameters, matrix effect (ME ٪), reduction behaviour, processing factor (PF) in contaminated tomato and orange fruits. The third part was focused on the development of photocatalytic degradation of metalaxyl, chlorpyrifos, and diazinon from artificially contaminated tomato puree and orange puree. Results of the first part showed successful trends by evaluating validation parameters [selectivity, linearity, limits of detection (LOD), limits of quantification (LOQ) and precision]. The correlation coefficients were [0.99; the LOD ranged from 0.01 to 0.003 mg/kg and the LOQ ranged from 0.03 to 0.009 mg/kg. The matrix effect (ME ٪) of metalaxyl was found to exhibit a medium matrix effect while for chlorpyriphos has no matrix effect. Recovery (70–120٪) and precision (RSD<20٪) for all pesticides were within the satisfactory ranges recommended by the European Commission. The PF was generally < 1 (ranged between 0.34 and 0.98). Except when using washing solutions, the highest reduction rate was achieved by sonication treatments which could effectively remove chlorpyriphos residues spiked in tomato matrices rather than the metalaxyl residues. On the other hand, washing treatments were less efficient in removing metalaxyl residues from tomato samples. Results of the second part investigate the effect of the household processing on the reduction rate of chlorpyrifos, metalaxyl, and diazinon residues in contaminated oranges and the processing factors were determined. The evaluation included validation parameters, matrix effect (ME ٪), reduction behavior and processing factors (PFs). Validation parameters were successfully applied; the three pesticides showed satisfactory recovery (70–120 ٪) and precision (relative standard deviation RSD<20 ٪); they also exhibited no matrix effect. The most effective process in the pesticide residue reduction was juicing, followed by pulping while the washing process was less efficient in removing all pesticide residues; sonication showed a high reduction rate with both chlorpyrifos and diazinon. The processing factors (PFs) were generally less than one which indicates that all processes can reduce pesticide residues in oranges. Results of the third part focused on the development of photocatalytic degradation to be a promising method for the treatment of decontaminated fruits and vegetables with pesticides. We investigate the coupling between Laser irradiation with TiO2 nanoparticles catalyst in order to study the photocatalytic degradation of metalaxyl, chlorpyrifos, and diazinon from artificially contaminated tomato puree and orange puree. The degradation percentage of all pesticides was achieved under optimized conditions (1g/L catalyst at the irradiation time of 120 min). The study proved that the coupling between TiO2 nanoparticles and laser irradiation has a high potential for photocatalytic degradation of diazinon, chlorpyrifos, and metalaxyl from orange puree and tomato puree. Maximum reduction >80٪ was observed in diazinon in all puree treatments. The processing factor (PFs) was generally less than one which indicates that all processes can reduce pesticide residues in all puree treatments. The less efficient removal of pesticides residues from all treatments without Laser irradiation (dark TiO2100mg).