Reader Hermes asks, since I mentioned that heat treating is only the “most popular” way to denature (wreck) browning enzymes in fruit, what other methods are there? A great question I’d be happy to answer, Hermes.
Acids do a great job of stopping browning enzymes from going to work on phenols. Depending on how strong they are they can slow down the the functioning of an enzyme, stop it from functioning altogether, or denature (gank) it. Ascorbic acid (lemon juice) and acetic acid (vinegar) are popular for this purpose.
Antioxidants inhibit browning by reacting with — and thereby using up — the oxygen that browning enzymes need to function. Ascorbic acid happens to be an antioxidant as well as just an acid, which is why a small dose of it on, say, a cut pear does a very nice job of maintaining its color and texture. As I mentioned earlier, immersing the fruit in water or wine works as well, since that deprives enzymes of oxygen as well.
And then of course there’s good ol’ sulphur dioxide, which bonds to the phenols and prevents browning enzymes from interacting with them. The application of sulphur dioxide is known as “sulfuring” and it’s a process that’s gotten a bad rap in recent years, though the ancient Egyptians and Chinese employed it for millennia and never complained. There’s just no pleasing some people.