City Paper is not for tourists
This week’s question comes from Erin Ferguson of Gaithersburg, who wants to know:
“Why does leaving the pit in the avocado keep it green longer?”
Because the avocado pit is so big and bad-ass the flesh can’t help but be green with envy? Okay, so a joke doesn’t answer your question, Erin. But, frankly, I’ve never thought the pit did much of anything other than take up too much room inside the fruit, which would be better filled with lush, fatty flesh. I came to my belief the hard way. I, too, once trusted that old wives’ tale about plopping the pit into freshly made guacamole if you want to prevent browning. Yeah, right, and strippers really do want you.
Well, I guess there’s a reason why I’m a food writer and not a food chemist.
Barry Swanson, professor of food science at Washington State University and a fellow at the Institute of Food Technologists, tells me that avocado pits actually do contain a group of chemicals—called flavonoids—that slow down the browning process.
Just don’t expect miracles from your pit. The truth is, once you disrupt the cells in the avocado, allowing enzymes to mix with substrates, the browning process is an inevitable as Viagra spam in your inbox. The pit, Swanson says, “will slow the browning reaction a little bit. So…for example, if [you] took a knife and cut it to the pit, it’s going to brown a little bit less probably in the center than it will on the outside.” Likewise, the pit will help slow browning in your guacamole “a little bit,” the professor says, “but probably not a whole lot.”
If you really want to keep your guac green—and I know you didn’t ask for this, Erin, but we’re all about service here at Ask Tim—Swanson suggests two things: The first is to blend your fat-heavy guacamole well and “get an emulsion going….If you blend it up really good, there’s so much fat involved” the enzymes and substrates may not get together to do their browning dance.
The second thing is to make sure to add lemon or lime juice to your guac, preferably lemon since it apparently has more of the acid you need to slow down browning. “Lemon juice containing citric acid is going to help you keep it much greener than the pit ever will,” Swanson says.
Of course, since just about every recipe calls for either lemon or lime juice, most guac makers will already have built-in safeguards against browning—unless, that is, you’re allergic to citrus juices and ignore those ingredients. Then I guess that leaves you in the pits.