Edible Spider Silk Coating Keeps Fruit Fresh Without Refrigeration

丝素涂层能够延长蔬果的保鲜期

A new technological development may mean a significantly longer life for fruits and vegetables. Biomedical engineers at Tufts University have shown that coating fruit in an odorless, edible, water-based silk solution can keep fruit fresh for more than a week without refrigeration.

最近，一项新技术的发展可能意味着水果和蔬菜的寿命将大大延长。塔夫茨大学的生物医学工程师们已经证明，将无味且可食用的丝素水溶液涂覆在蔬果表面可以使蔬果保鲜一周以上，而且不需要冷藏。

But this isn't just about extending the life of that banana on your shelf you keep telling yourself you should eat any day now. As food travels along the supply chain from farm to consumer, according to the UN's Food and Agriculture Organization, the world loses half of the fruit and vegetable crops grown for human consumption.

但是这不并是说你可以将香蕉等水果一直放在架子上，然后告诉自己你随便什么时候吃都行。毕竟，这只是延长一点保鲜的时间，并不是无限制地延长。联合国粮食及农业组织的数据显示，在食物沿着供应链从农场到消费者的过程中，整个世界损失了大概一半用于人类消费的水果和蔬菜作物。

"Food waste has an impact on food quality and safety," the authors write, "representing a loss of economic value and resources, and, a hindrance to economic development."The researchers published their findings today in the journal Scientific Reports, outlining how the silk fibroin, a protein essential to silk and spiderwebs and similar to collagen, can be suspended in water to create a 1 percent protein solution. Dissolvable film made from silk fibroin has previously been used to create implantable brain electrodes and as adhesive, edible sensors to monitor fruit ripening and cheese aging.

该研究的作者写道：“食物的浪费对食品的质量和安全都有着影响，也说明经济价值和资源在损失。同时，食物的浪费也是经济发展的一个重大阻碍”。研究人员们在最新一期的《科学报告》杂志上发表了他们的研究成果，概述了丝素如何悬浮在水中从而产生1%浓度的蛋白质溶液。在此之前，用丝素制成的可溶解膜曾被用来制造可植入的脑电极、粘合剂以及用于监测果实成熟和奶酪老化的可食用传感器。

The scientists tested with strawberries — one of the hardest fruits to keep fresh — and bananas in their study, dipping the perishable fruits into the solution to provide a nearly invisible, coating 27 to 35 microns thick — that's just one one-thousandth of an inch. This coating reduced the fruit's cell respiration rate by regulating the natural flow of oxygen and carbon dioxide, and slowed the rate at which water in the fruit evaporated — essentially, slowing down the decomposition process

研究人员在他们的研究中使用了草莓(最难保持新鲜的水果之一)和香蕉这两种水果。他们在易腐败的水果表面用丝素水溶液创造了一个近乎看不见的(厚度大约只有27到35微米)薄膜。这一层薄膜通过调节氧气和二氧化碳的自然流动来降低水果的细胞呼吸速率，并减缓了水分蒸发的速度。从根本上说，就是减缓了分解过程。

Current coating methods of fruit preservation include applying layers of polysaccharides, proteins, resins, lipids and combinations of different materials, all with different properties. The scientists say that, in addition to reducing food waste, this development using silk fibroin would mitigate some of the drawbacks of other forms of coating, providing a substance that's biodegradable, anti-allergenic, antibacterial and antifungal.

目前使水果保鲜的涂层材料包括多糖、蛋白质、树脂、脂类和不同材料的组合，不同的材料具有不同的性质。研究人员表示，除了减少食物浪费，这种丝素纤维素也没有其他涂层的那些缺点，将为我们提供一种可生物降解、抗过敏、抗菌的物质。

The coating process resulted in no discernible change in the fruit's texture, although the study notes that the scientists didn't test for any change in taste.

尽管这项研究指出，研究人员并没有测试水果的味道是否有任何变化，但我们可以肯定，涂覆薄膜的过程并不会使果实的质地发生明显的变化。