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Nagging Question
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How Does Packaged Guacamole Stay Green?You have to tame a certain enzyme |
Avocados contain an enzyme called polyphenol oxidase (it’s also in other fruit, like apples). When it consorts with oxygen, brown pigments form in the green flesh. That’s why when you leave out freshly made guacamole or a cut-up avocado, it turns brown quickly. But packaged guacamole always seems to be bright green upon purchase, despite having sat on the shelf for countless days.
Manufacturers have to make sure there’s no oxygen present in their packaging if they want the product to stay green, says Ardy Haerizadeh, the CEO of guacamole manufacturer Yucatan Foods. They can do this by vacuuming the oxygen from packages, having plastic film in contact with the top of the guacamole, or filling the headspace of tubs with nitrogen gas.
The enzyme is also sensitive to temperature and acid, so manufacturers can maintain the green color of their guacamole by refrigerating the product and by adding citric acid and/or ascorbic acid, says Diane M. Barrett, director of the Center for Fruit & Vegetable Quality at the University of California–Davis. Acids lower the pH “to the point that the enzyme is not that active,” explains Barrett, who adds that enzymes are also “less active at cold temperatures.”
Refrigeration, adding lemon or lime juice, and limiting exposure to oxygen can also help keep homemade guacamole from turning brown. Chowhounds offer a helpful guacamole timetable for a seven-layer dip.
On a related note, if you do buy commercially prepared guacamole, read the ingredients carefully. Haerizadeh says the FDA hasn’t created a standard of identity for the dish, so manufacturers can label pretty much anything they want as guacamole, whether it’s 95 percent avocado, or a “guacamole flavor” dip that contains less than 2 percent avocado.
Kraft's guacamole flavored dip seems awful! The ingredients!!
I like making guaca, it's good fun. Never had a problem with the colour, although I do add a small squeeze of lime. Stays green for days, not sure why.
Wholly Guacamole is my fave store brand. It's tasty, all natural, and is vacuum packed into plastic pouches for freshness. Will stay green for up to two hours after opening, too, as long as it's not outside.
I make Guac often and the idea of oxygen turning the guac brown makes sense. I add lime juice to my recipie and squeez it on top before putting it in the refrigerator. I have an inert gas for wine called "Private Preserve" which has argon and nitrogen. I am going to try it next time. Also putting it into a zip lock bag and squeezing all the air out might work as well!
i agree about the wholly guac
Like raw potatoes, raw artichokes, and apples, avocado gets brown with oxygen. By adding lemon juice, lime juice or vinegar (soak in lightly vinegared "acidulated" water for potatoes or uncooked artichokes) the acid prevents the oxidation and keeps your food looking the color it should.
When you make your own, putting an avocado pit (whole) in the dip can help as well.
Seed will not stop the reaction, it's an old wives tale.