Acidulated Water

Acidulated water is water where some sort of acid is added—often lemon juice, lime juice, or vinegar—to prevent fruits or vegetables from browning so as to maintain a visual purity. Some vegetables and fruits which are often placed in acidulated water are: apples, avocados, and pears. When the fruit or vegetable is removed from the mixture, it will usually resist browning for at least an hour or two, even though it is being exposed to oxygen.
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Water to which a mild acid, usually lemon juice or vinegar, has been added to prevent sliced fruits (especially apples and pears) and peeled or cut up vegetables (i.e. artichokes and salsify) from turning dark during preparation. To make acidulate water, squeeze half of a lemon into a medium bowl of water.