Exploiting safer methods for fruit preservation such as application of edible coatings can improve shelf life, valuable characteristics, and antioxidative capacity. The current study aimed to investigate the effect of a pectin-based edible coating on antioxidative capacity of plum fruit during shelf life (19 ± 2 ℃ and 65% relative humidity for eight days). To do this, three solutions (0.5, 1, and 1.5%) of pectin, plasticized by glycerol (0.3% w/v), were applied on plum fruit and compared to a control treated with only distilled water. Ascorbic acid, total phenolics, anthocyanin and flavonoid contents, total antioxidative capacity based on 1,1-diphenyl-2-picryl-hydrazyl hydrate method, peroxidase (as an antioxidant enzyme), and polyphenol oxidase (as an oxidant enzyme) activities were recorded during this period. The results demonstrated that pectin-based edible coating was significantly effective on maintaining ascorbic acid, anthocyanin and flavonoid contents, and antioxidative capacity in plum fruits (P ≤ 0.01). The activities of enzymes were significantly affected by the coatings; peroxidase activity increased and polyphenol oxidase activity decreased (P ≤ 0.01). All pectin concentrations significantly caused higher ascorbic acid and anthocyanin contents, antioxidative capacity, and peroxidase activity but a lower polyphenol oxidase activity than the control; however, just 1 and 1.5% concentrations were effective in terms of total phenolic compounds and flavonoid content, respectively, and the other concentrations acted the same as the control. In general, the coating constituted from 1.5% pectin showed the best results for most measured parameters. Considering the influences of pectin-based edible coating on antioxidative characteristics of plum fruits, its application can be potentially regarded as a favorable method to enhance nutritional value of fruits.

开发更安全的水果保鲜方法，例如可食用涂料的应用，可以提高保质期，有价值的特性和抗氧化能力。当前的研究旨在研究果胶基可食用涂料对李子果实在货架期（19±2℃和相对湿度为65％的八天）中抗氧化能力的影响。为此，将三种由甘油（0.3％w / v）增塑的果胶溶液（0.5％，1％和1.5％）施用于李子果实，并与仅用蒸馏水处理的对照进行比较。记录抗坏血酸，总酚，花青素和类黄酮的含量，基于1,1-二苯基-2-吡啶-2-肼基水合物法的总抗氧化能力，过氧化物酶（作为抗氧化酶）和多酚氧化酶（作为氧化酶）活性在这段时期。结果表明，基于果胶的可食用包衣在维持李子果实中的抗坏血酸，花色苷和类黄酮含量以及抗氧化能力方面具有显着效果（P≤0.01）。涂层的活性显着影响了酶的活性。过氧化物酶活性增加而多酚氧化酶活性降低（P≤0.01）。所有果胶浓度均显着导致抗坏血酸和花青素含量，抗氧化能力和过氧化物酶活性升高，但多酚氧化酶活性低于对照组。然而，就总酚类化合物和类黄酮含量而言，分别只有1％和1.5％的浓度有效，其他浓度与对照相同。通常，对于大多数测量参数，由1.5％果胶构成的涂层显示出最佳结果。