A "miracle" berry which can make sour foods taste sweet without any calorific penalty has become the centre of a new fashion fad in America.
The small West African berries - Synsepalum dulcificum - contains a glycoprotein which temporarily masks the mouth's ability to taste bitter and sour flavours.
When the pulp has been thoroughly chewed it can make tangy lemons taste like sugary lemonade and give vinegar a treacle-like flavour.
The red berries have become popular in New York and San Francisco where the latest fashionable night out is a "fruit-dropping" or "flavour tripping" party.
Guests are invited to eat the grape-sized berries and then sample a selection of food and drink, from chilli sauce to Irish stout, and revel in the distorted flavours.
Franz Aliquo, one party organiser, hands his customers a berry each then ushers them toward a table laden with citrus wedges, cheeses, Brussels sprouts, mustard, vinegars, pickles, dark beers, strawberries and cheap tequila.
The 32-year-old, who holds the events in Long Island City, Queens, said: "You pop it in your mouth and scrape the pulp off the seed, swirl it around and hold it in your mouth for about a minute, then you're ready to go."
One guest, Yuka Yoneda, claimed the fruit made Tabasco sauce taste like "hot doughnut glaze", while another, Carrie Dashow, said a glass of Guinness became like a "chocolate shake".
In Britain the demand has also begun to take off and the country's two main suppliers have warned customers that they will have to wait weeks before getting any.
The berries may also have significant health benefits. It is possible they could be used as a natural sweetener in foods for diabetics or as a supplement to help people lose weight without being tempted by sugary treats.
Some fruit growers even claim the berries are popular with cancer patients who undergo chemotherapy, because they can help diminish the unpleasant aftertaste.
However, these effects are yet to be backed up by scientific evidence.