Thesis (Ph.D.) - Cairo University - Faculty of Agriculture - Department of Food Science and Technology

The present study aimed to estimate penconazole and chlorfenapyr residue in grape, apple fruits and their products, to determinate the rates of fungicides dissipation, half-life values (RL50) and pre-harvest intervals (PHI) and analyzed physical, chemical and biologically. Applications of penconazole and chlorfenapyr pesticides were carried out on grape and apple fruits grown in the open field at Kalyoubia Governorate, samples were collected after (one hour, one day, 3, 5, 7, 9, 11, 15 and 21 days) of application. The pesticide residues were analyzed by GLC and HPLC. The PHI time was 3 and 10 days after penconazole application for grape and apple for fresh fruits or juices product. The PHI time was 21 day after the chlorfenapyr application for grape and apple, that for fresh fruits or juices product. The penconazole residue in grape and apple RL₅₀ was 2. 62 and 1.11 days, respectively, while the RL₅₀ for chlorfenapyr was 2. 86 and 2. 64 days for grape and apple, respectively. Viscosity, total acidity and T.S.S. observed slightly alterations but not significant for fresh, juice or jam samples. The tested pesticides were influenced (slightly increased) on minerals contents for grape and apple samples. The slightly increased in ash by pesticides application was confirmed by the increases in all minerals. Vitamins (A, B₁, B⁴ and C) content were slightly decreased by pesticide application. Total phenols and flavonoids were decreased in their juice or jam. Also, grape contained more amounts than apple

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