Who would have guessed nature had already invented a way of preserving apple juice?
If you've ever pressed your own apples or purchased fresh-from-the-press juice, you know that the tasty liquid quickly turns brown, just as an apple turns dark after the fruit has been cut or bruised. The culprit, an enzyme known as polyphenol oxidase, also destroys the vitamin C in apple juice within a matter of days and gives the drink a less-than-fresh flavor. Commercial juice producers add a pectin enzyme to inhibit clouding and add sulfites to prevent browning and flavor change. Sulfites, however, can cause serious (sometimes fatal) allergic reactions in some people, so scientists have been looking for a safer way of preserving apple juice. Cornell University scientists have identified a particularly toothsome alternative: honey. Mixing just 2% honey by weight with browned apple juice and letting the liquid sit at room temperature for 90 minutes clears the drink and prolongs the shelf life of the juice just as effectively as sulfites.