大蒜精油-羧甲基纤维素钠复合涂膜提高草莓贮藏效果

为了减少草莓在贮藏过程中的腐败变质延长草莓保质期,在质量分数为1.0%的羧甲基纤维素钠溶液中添加大蒜精油(体积分数:0、2、4、6μL/100 m L)制成复合溶液作为涂膜材料,涂膜液浸泡30 s于新鲜草莓表面,分析草莓在(20±2)℃贮藏过程中的品质变化。结果表明,与对照组未涂膜相比,大蒜精油-羧甲基纤维素钠复合涂膜材料能显著(P0.05)降低草莓在贮藏过程中的的呼吸作用强度和腐烂变质(P0.05),减少果实失重率;延缓草莓果实花色苷的分解,有良好的护色作用;另外,大蒜精油-羧甲基纤维素钠复合涂膜材料减少了草莓中可滴定酸度、维生素C、可溶性固形物的分解及丙二醛的累积。综合不同处理组草莓在贮藏过程中的品质变化,确定当大蒜精油添加量为4μL/100 m L时,草莓有较佳的保鲜效果,可为草莓果实的贮藏保鲜方法提供参考。

Garlic oil -sodium carboxymethyl cellulose composite coating material improving strawberry preservation effect

The strawberry (Fragaria x ananassa) is the most popular and year-round available berry in China and mainly consumed as fresh fruit. It is a kind of easily perishable fruit, which makes it impossible to store for a long term; thus, it should be used very quickly after harvest. Many products such as juice, jelly, nectar, puree, concentrate or jams have been developed. Despite the demand for these products, there remains an excess of strawberry crops. A possible alternative is to generate new preservation method that maintains the fruit’s original quality to the maximum extent, which can either retard or inhibit the physico-chemical changes occurring and improve fruit storability. The application of edible coatings is one of the most innovative methods to extend the commercial shelf-life of fruits and vegetables by acting as a gas barrier and having a similar effect with the storage under modified atmosphere, which reduces quality changes and slows down quantity losses through modification and control of the internal atmosphere of the individual fruit. Edible coating has a thin protective layer that is applied to the skin surface of the fruit and later consumed together with the fruit flesh. Sodium carboxymethyl cellulose (Na-CMC) is a naturally-occurring compound that enjoys the potential in agriculture due to its controlling plant diseases. Garlic oil is a kind of natural essential oil, which can be evenly dispersed in Na-CMC/chitosan solution to form an edible semipermeable film on the outside surface of the fruits to extend storage life and reduce some forms of decay caused by fungi during the storage. The objective of this work was to evaluate the effect of Na-CMC/garlic oil coating on respiration rate and quality characteristics of strawberry during its storage. Fresh strawberry was treated with garlic oil/Na-CMC composite film material and then stored at 6 ℃ or 20±2 ℃ for 6 d. Changes in weight loss, respiration rate, rot index, titrable acidity, soluble solid content, ascorbic acid, and malonaldehyde content were periodically recorded. The results indicated that garlic oil/Na-CMC composite film material was effective in reducing weight loss, respiration rate as well as decay rate, significantly reduced the strawberry quality changes during the storage process, and achieved the purpose of keeping the freshness of strawberry. A trend in delaying the decomposition of the anthocyan and color-protecting was observed for coated strawberry. As the garlic essential oil content of composite film material was 4 μL/100 mL, the coated strawberry had the best quality during the storage.