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长点点的水果和蔬菜能吃吗? – 译学馆
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长点点的水果和蔬菜能吃吗?

Are spotty fruits and vegetables safe to eat? - Elizabeth Brauer

2010年 价值三百亿美元的蔬菜水果
In 2010, $30 billion worth of fruits and vegetables
被美国的商家和消费者白白浪费掉
were wasted by American retailers and shoppers
其中一部分是因为品相问题和表面的污损
in part because of cosmetic problems and perceived spoilage.
这些损失就占到了市场上30%的农产品
That’s a poor use of about 30% of the produce on the market,
更不用说其生长和运输过程中所耗费的水电了
not to mention the water and energy required to grow and transport it,
连垃圾场也不得不腾出空间来倾置腐烂的水果
and the landfill space getting used up by rotting fruit.
那么品相问题是什么?
So what are those cosmetic problems?
你一定在水果店嫌弃过带有斑点的苹果
You’ve probably passed over a spotty apple in the grocery store,
或是不小心捏到了番茄上塌软的部分
or accidentally sunk your thumb into a mushy patch on a tomato.
这些污损注定了这样的农产品要被扔掉
These blemishes can doom produce to the trash can.
但它们究竟是什么
But what are they anyway,
对我们真的有害吗?
and are they actually bad for you?
这些污损实际上是微生物侵入植物的证据
Those spots are evidence of an epic battle between plants and microbes.
和人类一样 植物生长的环境也存在着数不尽的真菌和细菌
Like humans, plants coexist with billions of fungi and bacteria.
有些是对植物有益的
Some of these microbes are beneficial to the plant,
比如抑制病虫害和增强养分吸收
suppressing disease and helping it extract nutrients.
其它则是病原菌 能够破坏植株
Others are pathogens, attacking the produce,
即使蔬果被摆上了商品架或者放入冰箱 它们还有残留
still alive as it sits in a store display or your refrigerator
继续榨取宿主养分以供自己存活
and siphoning off molecules they can use themselves.
所幸它们对人体几乎是无害的
The good news is they’re almost never bad for you.
这些真菌和细菌已经用了几百万年的时间
These fungi and bacteria have spent millions of years
进化出抵御植物免疫系统的能力
developing strategies to overcome a plant’s immune system.
但是由于健康人体的免疫系统和植物的大相径庭
But healthy human immune systems are different enough
它们的抗免疫能力对我们不起作用
that those strategies just don’t work on us.
那么在植株上 这一过程是如何发生的呢?
So in a plant, what does this process look like?
微生物接触植株的方式很多样
Microbes can reach plants in a number of ways,
比如在浇水施肥的时候洒落到植株上
like getting splashed onto it during watering or fertilization.
然后在合适的条件下
Under the right conditions,
微生物繁殖成大块菌落
the microbes grow into large enough colonies
并开始破坏水果或者叶片的蜡状表皮
to attack the waxy outer layer of fruit or leaves.
它们的目标是内部美味的糖分和养分
Their target: the delicious sugars and nutrients inside.
这种病原菌通常会导致这样的斑点
This type of pathogen often makes spots like this.
凝块的细菌摄取养分促使水果细胞发生了颜色变化
A clump of bacteria drains the nutrients and color from the fruit’s cells
出现黄色的圆形斑点
making that yellow halo.
之后它们向外扩散
It then moves outward,
在待过的地方留下黑斑状的死细胞
leaving a black spot of dead cells in its wake.
一个斑点里可能有成百上千的微生物
Each spot, which could contain hundreds of thousands of microbes
实际上这是它们入侵和宿主自卫的过程中
is actually caused by a combination of microbial attack
共同造就的产物
and the host defending itself.
举个例子 这是丁香假单胞菌
For example, this is the bacterial pathogen Pseudomonas syringae.
一旦接触到番茄 它就会侵入果实和叶子
Once on a tomato, it enters the fruit and leaves,
在细胞间隙繁殖
multiplies in the space between the cells,
分泌毒素和蛋白质
and produces toxins and proteins
从而使植株的免疫反应失效
that allow it to disrupt the plant’s immune response.
一旦有毒的冠菌素打开了植株的气孔
One toxin coronatine makes plants’ stomata open up,
细菌入侵就畅通无阻了
allowing bacteria to enter more freely.
冠菌素同时还能降解叶绿素
Coronatine also activates pathways leading to chlorophyll degradation,
所以我们才会看到黄色的斑点
which you can see as yellow spots.
随着细菌不断得到滋养和繁殖
As the bacteria continue to feed and multiply,
它们开始杀死植株细胞
they start to kill off the plant cells.
这是斑点的由来 但是塌软的部分又作何解释呢?
That explains spots, but what about mushy blemishes?
它们通常是在果实被微生物入侵
Those are usually caused when the fruit is attacked by microbes
并且离开后才形成的
after it’s detached from the plant.
如果植物在运输过程中表面受到破损
If the plant is wounded during transport,
坏死性真菌可以从伤口渗入
necrotic fungi can infiltrate through the wound,
杀死植株细胞
kill the cells,
榨取养分
absorb their nutrients,
导致食物看起来呈褐色或者塌软的样子
and leave your food looking mushy or brown.
这类斑点尝起来尤其难吃
Those spots in particular can taste pretty bad.
毕竟你吃下去的是坏死和分解后的组织
You’re eating dead and decomposing tissue, after all.
但是其余完好的部分还是可放心食用
But you can usually salvage the rest of the fruit.
你在苹果或番茄上常见的没有塌陷的斑点
The non-mushy spots, like the ones you typically see on apples or tomatoes,
只是不美观 但并不影响味道当然
are just on the surface and don’t usually affect flavor.
有些微生物是致病的 比如大肠杆菌和沙门氏菌
Of course, microbes that do make us sick, like E. coli and salmonella,
它们也会搭蔬菜的顺风车
can hitch a ride on vegetables, too.
但是因为它们不是植物病原菌 所以不会导致斑点
But because they’re not plant pathogens, they don’t typically cause spots.
它们只会无形地附着在表面
They just hang out invisibly on the surface.
因而正确的做法是清洗蔬果 而不是避开斑点
So it’s washing fruit and veggies, not avoiding the spotty ones,
这样才能让你预防疾病
that will help you avoid getting sick.
所以下一次你再去买水果
So the next time you’re at the grocery store,
请放心挑选看上去很丑的水果
don’t be afraid to pick up funky-looking fruit.
没准老板还会给你优惠
Some stores will even give you a discount.
只要洗干净它们
Wash them well and store them properly,
合理贮藏一些农产品如苹果和卷心菜是可以冷藏保鲜几个星期的
as some produce like apples and cabbages will keep in the fridge for weeks.
带斑点的蔬果也许不美观 但它们是安全的 而且同样美味
The spotty ones may not be eye candy, but they’re safe and just as delicious.

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