Kinetic study of ascorbic acid degradation from grapes
نویسندگان
چکیده
The aim of this study was to investigate the effect of storage at -4 0 C on the ascorbic acid (vitamin C) content of grapes (Vitis vinifera) for 1, 2, 5 and 8 months. A sensitive UV-VIS spectrometric method based on Prussian Blue reaction was applied for vitamin C determination and some kinetic calculations were presented. The varieties of red and white grapes used were from Murfatlar vineyard: Mamaia, Cristina and Columna. Fresh samples before storage and samples after one, two, five and nine month of storage in the freezer were investigated. The half time values of ascorbic acid degradation are between 160.78 and 232.23 hours, respectively between 2.9x10 -3 hours -1 and 4.3x10 -3 hours -1 for constant rate. It was observed that the concentration of ascorbic acid from studied grapes decreases with the increase of the storage time.
منابع مشابه
Effect of Foliar Spraying of Ascorbic Acid on Cell Membrane Stability, Lipid Peroxidation, Total Soluble Protein, Ascorbate Peroxidase and Leaf Ascorbic Acid Under Drought Stress in Grapes
Drought is the most common environmental stress in vineyard occurs in soils with low water content, even in irrigation condition. To evaluate foliar spraying of ascorbic acid under drought stress, a research during 2012 to 2013 years in the natural environment, and one year after the establishment of the cuttings in clay loam soil was conducted. Cultivars with two-level white seedless and khosh...
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