Modeling of Vitamin C Degradation Kinetics of Fresh Cucumis sativus as a Function of Edible Coating Kind and Storage Time

Vitamin C (L-ascorbic acid) is a basic nutrients and very effective antioxidant that acts as a natural preservative in fruits (such as Cucumis sativus). Aiming to maintain bioactive compounds (especially inhibition the dehydroascorbic acid formation) and preventing the spoilage development, the effect of edible coating types (I: control, II: Shiraz gum & III: Shiraz gum containing 1000 ppm Mentha piperita L. essential oil) and storage times (1, 8 and 16 days) on the auto-oxidation kinetics of vitamin C and its inhibitory role on inhibition of bacterial/fungal growth of Cucumis sativus at +4 °C, was evaluated. The results indicated that the variation rate of Cucumis sativus vitamin C degradation during storage period follows the zero-order kinetic reaction (the highest R2/P(%) ratio). The lowest growth rate of mesophilic bacteria (6.95), mold (3.21) and yeast (6.04) of Cucumis sativus in (log10 CFU/g) observed after 16 days of storage in sample (III) that corresponding to the lowest rate of vitamin C degradation. The half-time values (t1/2) of vitamin C degradation rate showed that, the best shelf-life of Cucumis sativus (in the studied conditions) was ~10 days, aiming to maintain the most nutritional properties. Generally, the findings of present research can be useful for monitoring the shelf life of Cucumis sativus kept in cold stowage.