My Guac actually stayed green!

So this week in my MIT course in Kitchen Chemistry, I just learned a lot about avocados: the basics of their cellular/molecular structure, why they turn brown so quickly, and how to prevent that chemical reaction. So last night, I put it all into practice when Aaron and I made guac to have on our tacos for dinner. 

OH! the creamy, buttery, delicious texture and flavor! We miraculously had leftovers... Imagine my surprise when I looked this morning to find our guacamole remained green! That's NEVER happened to me before!!! So now I eat leftover guacamole and it is SO satisfying.

A basic guacamole recipe is below, along with each of mine and Aaron's variations. You can read the text after the recipes to figure out which ingredient contributed our success. :)

Basic Guac

2 avocados
onion, chopped (I actually left this out 'cuz I don't like raw onion)
3/4 tsp. sea salt
juice of half a small lemon

Aaron's Vartion
4 finely diced jalepeno pepper, with most ribs and seeds removed.

Allyson's Variation:
1 - 2 Tbsp. coarsley chopped cilantro 
1 large roma tomato, diced
1/2 tsp. garlic powder
lime zest, to taste.

Combine avocado, salt and lemon juice. Mash with fork (for slightly chunky texture) or Puree in Food Processor (for a creamy texture).

Gently fold in the chopped onion and add-ins.

Enjoy with chips, over tacos, etc. 

TO STORE: Cover tightly with plastic wrap in an air tight container, in the refrigerator up to 3 days.

Here's a bit of what I learned - 

Chemical Reactions
Part of the physical makeup of an avocado is an enzyme called, polyphenol oxidaise (PO). This enzyme hangs out in the cells of the avocado and is highly sensitive to oxygen. Once an avocado is cut, it's cell structure is broken, thus exposing this enzyme to air. Long story made short (and without too many crazy words that very few will care to read), this PO begins to create chains that link together and creates the brown color you see in an avocado. 
You can do three things to minimize this reaction. A) Cut off it's air supply and wrap it tightly with cling wrap. B) The avo's main enzyme is also sensitive to acid, so adding a bit of lemon or lime juice will slow the reaction. C) Cool temperatures also slow the reaction, so store the exposed avocado in the fridge. To be safe, I would do all three when possible. 

Health Benefits
As a fruit, avocados are unique in that they have very low sugar/starch content, and a very high oil content (the healthy kind of oil) - up to 30%. These oils provide a significant supply of lutein, a protein that is also found in the human body, highly concentrated in the macula of our eyes. Eating avocados has been found to help in preventing age related macular degeneration. As a diabetic, I find this extremely beneficial. Diabetes may primarily effect my eyes' blood vessels, but I also worry about my eye health, in general. So bring on the avocados!

To learn more about this course, click here: Guacamole.