揭祕：切洋蔥如何不流淚？
1. 切洋蔥前先冷藏或冷凍
According to the Institute, putting onions in the fridge 30 minutes or in the freezer for 10-15 minutes before chopping can prevent the stinging as the cold stops tear-jerking gas from being produced.
根據研究所的說法，在切洋蔥之前，先將它們放入冰箱30分鐘，或放入冷凍室10到15分鐘，便可以防止流淚，因爲冷氣能阻止其釋放催淚氣體。
However, do not start storing your onions in the fridge at all times as this will cause them to go off more quickly.
但是，不要一直把洋蔥放在冰箱裏，這樣會讓它們壞得更快。
2. 將洋蔥浸泡在水中
Another way to reduce the gas released by the onion is to soak in water - although this could compromise the taste.
減少洋蔥釋放氣體的另一種方法是將其浸泡在水中——儘管這樣可能會影響它的味道。
Good Housekeeping recommends: ‘Chop the end off the onion and then put it straight into a bowl of water to soak. The water will draw out the acid making you tear up less when you chop it.’
《家政》建議：“切掉洋蔥的末端，然後把它們直接放入一碗水中浸泡。水會抽出洋蔥中的酸味物質，所以切洋蔥時，就能減少流淚。”
3. 最後切洋蔥根部
When an onion grows it mixes with sulfur in the soil to create amino acid sulfoxides. These sulfoxides turns into sulfenic acid when the onion is sliced which reacts with the enzymes to create a gas called syn-propanethial-S-oxide.
洋蔥生長時，與土壤中的硫混合，從而產生氨基酸亞碸。而洋蔥被切成片時，這些亞碸會變成次磺酸，與酶反應後產生名爲丙硫醛-S-氧化物的氣體。
As it reaches your face, this irritating gas stings and burns, triggering the eyes to produce tears to flush out the gasses.
這種刺激性氣體接觸面部時，你的眼睛會感到刺痛和灼燒，然後你便會開始流眼淚來排出眼睛內的氣體。
The root is where the fumes are most concentrated so it is recommended that this part of the onion is left on as you chop it to avoid stinging eyes.
洋蔥的根部是氣體最集中的地方，所以雜誌建議，在切洋蔥時最後切這一部分，以免刺激眼睛。
4. 在通風處切洋蔥
Another way to reduce the gas’s effect on your eyes is to chop it next to a window or near a fan so the gas is diluted or blown away from your face.
另一種減少氣體刺激眼睛的方法是在窗戶邊或者風扇旁切洋蔥，這樣氣體就能從你面前被稀釋或吹走。
5. 使用鋒利的刀具
And take care to use a sharp knife, this will make it easier to glide through the vegetable, causing fewer cells to be broken and less gas to be released as a result.
注意使用鋒利的刀具，切開洋蔥時更容易，減少對細胞的破壞，從而減少其釋放的氣體。
The type of onion you use can also make a difference. The enzymes required to create the tear-inducing gas are more concentrated in white, yellow and red onions compared to sweet onions, green onions and spring onions.
洋蔥的種類也有影響。與甜洋蔥、大蔥和小蔥相比，刺激流淚的氣體所需的酶更集中於白色、黃色和紅色的洋蔥中。
