As-salt on sweet pineapples.

Taste. Brain signals. Ions and acids. And why pineapples taste sweeter with salt.

pineapples salt bitter sweet (jpg) Screen Shot 2015-09-17 at 8.50.44 am1-Minute NomNom

Some families practice rubbing salt to reduce the burn from the pineapples bromelain (read all about how pineapples make us feel red hot in the 1-Minute NomNom “Tongue (pro)teases“).  There however does not seem to be scientific evidence that this actually works, but somehow we feel better.  So what is actually going on?

pineapple tongue bromelain proteases iStock_000033643016_LargeWe have five primary tastes: sweet, sour, salty, bitter, and umani. We think of them as distinct tastes but they interact in fascinating and counter-intuitive ways. For example, adding salt to pineapples actually makes them sweeter!

According to ABC Science and Now I Know, there are two possible explanations for this.

osmosis and diffusion - Sea salt on cloth and wooden plate in kitchen.

The first is that salt neutralizes the sour acids in pineapples, thus accentuating the sweetness. When salt or sodium chloride “dissolves into the pineapple, it will break apart into sodium and chloride ions.” Chloride ions have no taste, while the sodium ions react with the pineapple’s acids to form “tasteless” and “neutral sodium salts”.  What is left is the sweetness of the pineapples.

salt makes pineapples sweeter - fruit juice and fresh pineapple juicyThis sweetness is accentuated further because salt also neutralizes the sensation of bitterness. Our tongue are full of taste receptors. They are the protein molecules on our tongues that give us the sensation of taste, which are sent as signals to the brain.

When they taste bitter and sweet at the same time, and sends these two signals to the brain, the brain will choose to “mutually suppress both flavours”. Salt however is known to neutralize the sensation of bitterness. So when we rub salt onto our pineapples, any bitter sensation present is suppressed and the brain only receives the sweet sensation.

sweets and candiesSo what might in fact be happening is that when we rub salt into the pineapples, they not only taste sweet, the sensation of sweetness is heightened. Our brains are wired to deem this as a reward, and thus it feels good. This mitigates the pain from pineapple burn. It is like offering a sweet to a child who has just injured himself – it does not help the injury but having a sweet to suck on makes things better 🙂

Feed Me!

What other fruits taste sweeter when eaten with salt? Share them with us in the comments below!


Screen Shot 2015-01-10 at 6.02.39 pmLike this? Be extra sweet and like me to discover more. All you need is a minute a day to explore the world’s marvels through the phenomenon of food!


photos: in order – istockphoto/mstay; depositphotos/leisuretime13; istockphoto/meteo021; depositphotos/miskolinseagamess; nito103



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