Vitamin C (ascorbic acid) is one of the most important and popular vitamins, and is contained in most fruits and vegetables; the problem with vitamin C is its easy degradation during pre-treatment and storage. In this study, kinetics modeling of degradation of ascorbic acid (Vitamin C) in lettuce, cabbage and carrot common vegetables dipped in Sodium Chloride at temperature ranges of (27.360C 29.92)0C were investigated and samples after dipping at various temperatures and timings were prepared for analysis and High Pressure liquid chromatographic (HPLC) was used for determination of the AA of the common vegetable samples which consisted of an isocratic elution procedure with UV-Visible detection at 245nm.The rate constants and half-lives were calculated using the integrated law method. Activation energy and forecast were determined using Arrhenius equation and time series analysis. Degradation of ascorbic acid in the commonly consumed vegetables under the same pretreatment procedure followed the first-order kinetic model, as the average coefficient of determination (R2-value) was greater than 0.91. The rate constant of ascorbic acid degradation for Lettuce, Cabbage and carrot dipped in NaCl under the same temperature condition of 27.360C were 0.0135, 0.0803, 0.0164 day-1 respectively. Their half-lives were 51.3442, 18.63197 and 42.26507min -1, activation energies; 161.5341, 18.5679 and 126.3887 Kcal/mol respectively. The ln(C) forecast of the vegetables dipped in NaCl for 60mins at 27.360C exhibited 2.1165, 0.5925, 3.1430mg/100g for lettuce, cabbage and carrot respectively. The proposed models at 27.360C were ln(C) = ln( C0) - 0.0135t, ln(C) = ln( C0) - 0.0803t, ln(C) = ln( C0) - 0.0164t.The most appropriate commonly consumed vegetable under dipped NaCl and storage is the lettuce because its rate constant depicted from the model equations was lower, half life longer, activation energy higher, forecast longer.
Key words: HPLC, Lettuce, Cabbage, Sodium Chloride, Ascorbic Acid, Rate Constant, Activation Energy, Forecast
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