Evaluation of Cold Plasma Effect on Shelf Life, Physicochemical and Organoleptic Properties of Cucumber (Cucumis Sativus Var. Negin)

Abstract

Non-thermal plasma is a new technique to reduce the microbial load in fresh fruits and vegetables, which can decontaminate the surfaces of fresh food products. This research used the atmospheric pressure jet discharge plasma of argon gas to treat cucumber samples. The treatments included two power levels (voltage of 17 volts with a current intensity of 2.66 amps and voltage of 10 volts with a current intensity of 0.86 amps) and four-time levels of plasma application (0, 2, 4, and 6 minutes) on the surface of cucumber samples. Cucumbers’ microbial, qualitative, and sensory characteristics were measured after plasma application and during storage at 250C in three periods, the first, fifth, and tenth days after plasma application. The results of the microbial analysis in plasma-treated samples with the machine’s high power showed a decrease of 2.59 logarithmic cycles in the total count and 1.388 logarithmic cycles in mold and yeast. No significant difference was observed between the tissue hardness and color indices of the treated samples immediately after plasma application and the corresponding values of the control sample in both powers. Examining the quality indicators of cucumber samples during storage showed the superiority of the treated samples compared to the control samples. The sensory evaluation of cucumber samples indicated that plasma had no adverse effect on the sensory characteristics of cucumbers. The aroma characteristics and general acceptability of the plasma-treated samples were significantly better than the control samples during the storage period. Based on the results, cold plasma is a new method for food processing. Due to its non-thermal nature, this technique can be a suitable alternative to other techniques used for the decontamination, pasteurization, and sterilization of food products, especially heat-sensitive products.