Level: Novice
Reading time: 9 minutes
I have had the question of oxidation and oxidation absorption capacity on my mind lately, and figured you were the person to question regarding this.
In many of the ORAC scales I've seen, I've noticed that cocoa powder scores roughly 49,000/100g while baking chocolate is ~ 60,000/100g. Doing a rough rounding to even 50% cocoa butter for the baking chocolate, we can see that consuming equal portions of cocoa solids from either source, the ORAC value of the baking chocolate is much higher. I was wondering if this was due to the processing involved in making cocoa powder and continual exposure to oxygen, or simply that many cocoa powders tested may be inferior.
Additionally, as I've been making many hot chocolates with my baking chocolate and storing overnight in the fridge for the following morning, I was wondering how much oxidation really occurs in this process (how much of this oxygen absorption capacity are we losing from storing overnight). I figured the surface tension/lack of movement/limited exposure to external oxygen would minimize this.
ORAC stands for Oxygen Radical Absorbance Capacity.
I’m going to start out and say I’m not a huge fan of the ORAC test. Or more to the point, I’m not convinced it is a good benchmark of the nutritional value of foods and/or there is much correlation between high ORAC values and human health.
I eat chocolate because I like the taste and it makes me happy. It is lovely that you may get some heart health benefits from dark chocolate but it isn’t my driving force and I don’t think it should be yours either.
Just a quick review of the validity of the ORAC test leads me to as many references supporting it as calling it an outright scam. After about an hour going down various research rabbit holes, I found this one sums my views pretty well.
Here is a quote from there that again is a great summary.
What’s good about an ORAC score?
· It’s an easy way to compare the inherent antioxidant capacity of different foods
· It measures antioxidant capacity regardless of how long it takes for the oxidation to take place
· The test is more or less standard and pretty accurate for what it measures
But that raises the question: what exactly does it measure?
It might not be what you think.
How An ORAC Score Might Be Misleading
The huge knock on the ORAC score is that it’s done in a test tube, and sometimes what happens in a test tube has no correlation to what happens in your body. None.
This is likely true for the ORAC test.
Why?
· The free radicals used in an ORAC test don’t occur in the body
· There are about 1,234,845.6 different types of oxidizing reactions that can take place in your body, and an ORAC score measures exactly 1 of them.
· ORAC scores can actually differ for the same food depending on the particular method used.
· ORAC scores can lower by as much as 90% when foods are cooked or processed
· Different antioxidant molecules behave very differently in an ORAC test
· The biological significance of the ORAC test has actually not been determined
· ORAC scores can be easily manipulated.
At best it means ORAC scores can be a general approximation of the antioxidant potential of a food. At worst it means an ORAC score can be completely useless and a tool for manipulation
Really, this is just me as a scientist needing pretty solid concrete studies before I jump on the latest nutritional bandwagon. You can keep reading that article if you like. At the end of the day I just need to remind you that dark chocolate, after accounting for age, sex and gender has shown some health benefits when eaten in moderation. Take that, and stop sweating the nitty gritty details and trying to squeeze every last possible benefit from every food source you consume. How about moderation in all things, ok?
With my Alchemist ranting diatribe done for now I’m going to move onto some of the specifics of the question.
So you are comparing 490/g vs 600/g (I just divided by 100 – these numbers are the same but easier to read) for unsweetened chocolate vs powder. First off, noting above just how far off the analysis can be, these numbers are nearly identical. After that, your accounting for the 50% fat isn’t right. Most cocoa powders still contain about 15% cocoa butter. If you really want to compare values you need the following:
490 / 0.55 = 890/g cocoa solid in chocolate
600 / 0.85 = 705/g cocoa solid in cocoa powder
I would not call (rounding) 900 vs 700 ‘much higher’ in the scheme of ORAC values.
But to answer your question, let’s assume the values are accurate and chocolate is higher. The answer is yes to at least two parts of your question. Cocoa powder is processed more. To press out the butter, nearly all cocoa masses are heated not insignificantly so that could indeed reduce the ORAC value. Also, the surface area exposed to oxygen is many orders of magnitude higher than in chocolate because it is in powder form and chocolate is encapsulated in cocoa butter. It is just a surface to volume ration thing.
I don’t think you can just assume the cocoa powder is inferior though.
As I was writing this, the numbers were sounding very familiar and it took me a little while to work out why. I’ve seen them before and they seem to be pulled from the exact page I recalled that made me skeptical about ORAC value in the first place.
My apologies, I am going to rant again. This is exactly the kind of ill put together meta study that I can’t abide where they claim their chocolate has twice the value of standard chocolate. Look at this:
This is comparing apples to oranges. There is no reason to think they didn’t cherry pick their data so their value was higher than some other UNRELATED chocolate. Their chart even shows that the range for can be has high as 1052 so the argument could be made that their chocolate is only 1/3 the potential it could be. The ONLY way to prove their process is any better is to process their cocoa as they do, and compare it directly to their cocoa processed in a more classic way. And then we are STILL left with this:
The huge knock on the ORAC score is that it’s done in a test tube, and sometimes what happens in a test tube has no correlation to what happens in your body. None.
Rant mode back off, but bad science gets under my skin.
Does your refrigerated hot chocolate have a higher or lower ORAC value than the night before because of no motion and the cool temperature? Who bloody knows? You would need to have it tested.
I don’t know your process, but if you are making hot chocolate you are introducing a LOT of energy and water naturally carries dissolved oxygen, so I suspect just the nature of making your baking chocolate into hot chocolate you are radically reducing the ORAC value (maybe by that 90% mark?). You’ve probably done all the damage to it just in the making and there is no lower it can go, so in that regard, I doubt your overnight refrigeration is doing any additional harm nor helping preserve anything.
Do I know this? Nope, I am just surmising.
Does it matter? I also don’t think it matters if you are enjoying your hot chocolate.