Effects of Shirazi Gum Edible Coating Containing of Peppermint Essential Oil on Shelf-life of Fresh Greenhouse Cucumbers (Cucumissativus) and Its Quality Assessment during Storage in Refrigerator

Background and Objectives: Greenhouse cucumber is one of the most important summer crops of Iran. Quality of the product is immediately lost after harvest due to physicochemical changes. Thus, use of special pre-processes (especially use of edible coating) to delay their maturity and increase the shelf-life of the product is important. Materials and Methods: To decrease weight loss, preserve nutritional value (protects against the breakdown of vitamin C) and texture brittleness (corresponding to the higher acceptability of consumers), greenhouse cucumbers were processed with various edible coatings; control (I), Shiraz gum (II) and Shiraz gum containing 1000 ppm peppermint essential oil (III). Then, physicochemical characteristics (pH, weight loss, vitamin C and hardness) and color parameters (L*, a* and b*) of the samples were assessed at storage days of 1, 8 and 16 at 4 oC. Results: While the vitamin C and firmness of uncoated greenhouse cucumbers (control) respectively decreased to 4.8 and 2.26 times during 16 days of storage, the highlighted parameters decreased at rates of ~3.85 and ~1.20 times in samples treated with coating (III) at similar conditions, respectively. Moreover, strong positive correlations between vitamin C and firmness factors (r = +0.9654 and R2 = 0.932) included significant effects on the perception of consumer mouth feels. Conclusion: Regarding that the control sample achieved only 57.5% of the maximum organoleptic score (flavor, aroma, color and texture), greenhouse samples treated with coating (III) achieved up to 94% of these characteristics and have been recommended as the best edible coating for the shelf-life extending of greenhouse cucumbers.