For
spicy food enthusiasts, Szechuan pepper
hotpot is one of the best winter treats. Strong
Szechuan pepper can cause your tongue to feel
tingly and partially paralyze your mouth and lips,
resulting in a feeling of numbness. For people who
are particularly sensitive to the spice, this feeling
sometimes spreads all over the mouth cavity.
Have you ever wondered why you experience a
tingly feeling after eating Szechuan pepper?
Spicy ber r y is the main culpr it involved in
generating the paralyzing sensation. The Northern
Ch i nese i s known fo r us i ng sp i cy be r r i es as
seasoning. While spicy berries are not actually
“spicy,” in the traditional sense, they do carry a
taste that resembles spiciness. According to New
Beijing News, a group of European scientists recently
discovered that spicy berries contain a component
called sanshoamide, which can stimulate certain
nerves in our body. This generates a frequency of
neural signals, which is what our brains interpret as
the tingling sensation.
What is the frequency of neural signals
generated by sanshoamide?
The scientists did a simple experiment. They
ground sanshoamide and mixed it with ethanol.
They then placed the mixture onto the lower lip of a
volunteer. At the same time, a finger of the volunteer
was placed on a vibrator for mechanical vibration.
When the volunteer senses a tingle, he or she would
convey to the scientists whether the frequency of
the tingling sensation from their lips were higher
or lower than that of the defined frequencies of
finger vibration. It took scientists forty trials before
they could equilibrate the two frequencies. They
eventually determined that spicy berries produce
a frequency of approximately 50Hz. This frequency
matches a class of nerve fibers, RA1, which has an
optimal sensitivity of around 50Hz to 100Hz. From
this information, the scientists concluded that spicy
berries stimulate RA1 fibers. The finding serves as a
plausible scientific explanation of why we feel tingly
when we eat Szechuan pepper.
Think about it: the electricity we use at home
typically has a frequency of 50Hz. It is not an
exaggeration to say that when we eat Szechuan
pepper hotpot, we are experiencing a mild electric
shock!
在天寒地凍的天氣下，對於一個嗜辣的人來說，相約一眾
好友圍坐一起享用四川麻辣火鍋絕對是最佳選擇。四川麻辣
鍋的辛辣能夠令食者有舌頭及嘴唇感到麻痺以及刺痛，這種
感覺慢慢地攻入腦中，熱騰騰的感覺攻陷全身，感覺快要頭
頂冒煙了……
在享受麻辣火鍋之際，大家有沒有想過為什麼嘴唇及舌
頭會感到麻痺及刺痛？
麻辣火鍋產生麻辣的主要成份是花椒。北方人喜歡用花
椒作為調料，它本身並不辣，但卻能帶出獨特麻辣口味，是中
國的特色產物。一個英國科研團隊最近發現，花椒含有一種
名為「花椒麻素」的成份，能夠激發我們身體某些神經，這些
神經會產生特定的振動頻率，繼而將信息送往大腦導致某種
感覺，而該感覺就是我們吃麻辣火鍋後感到的嘴唇舌頭麻痺
及刺痛。
但究竟花椒激發的神經振動頻率是多少？
科學家對此做了一個簡單的實驗。他們把花椒麻素磨成
粉末加入酒精塗在自願者的下唇，同時於自願者食指上綁著
一個振動器，當刺痛出現時，自願者需要判斷花椒刺痛感引
起的頻率比振動器高還是低，重覆四十次實驗，直至兩者頻率
相似。科學家由此推斷出花椒麻素產生的振動頻率為50Hz。
被稱為RA1神經的振動頻率剛好在50Hz-100Hz時最敏感，
因而確定花椒能激發RA1神經而誘發50Hz的振動，這種振動
頻率就是大家吃麻辣火鍋時感到的麻刺感。
試想想，香港一般家居用電的頻率亦是50Hz，如果說吃
過四川麻辣火鍋後感到像輕微觸電一樣的麻痺、刺痛之感，
也沒有誇張之嫌吧！生活中到處也是科學，簡單的實驗也能
得出偉大的結果，嘗試多留意身邊的事物，你也會得益良多。
Further Reading:
周哲
(2013
，
10
月
6
日
)
。吃完花椒嘴唇每秒振
50
次。金陵晚報，
A15
Harry, B. & Patrick, H. (2013). Food vibrations: Asian spice sets lips trembling, 280, 1770.
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