Sorry for the nasty title. I'm currently making a chocolate with a cinnamon inclusion. The cinnamon is from a local source, and I've cleaned and processed it myself. This species of cinnamon actually grows as a root, however, so there's probably no way of getting 100% of whatever was on it underground off. And it is basically raw.

I know things like garlic cannot be stored in oil due to concerns about botulism. Chocolate is largely oil (40%+ cocoa butter?), so I'm wondering if there's any concern here. How much oxygen is in chocolate? Is the pH low enough to prevent production of the toxin?

Haven't seen any info online, and only see one other post on TCL which admittedly says chocolate allows oxygen to "pass through" whatever that means lol

Anyway, jokes aside, botulism isn't funny, so if anyone knows something I'd love to hear it!

Thanks

Lee

updated by @lee2: 04/12/15 00:02:51

Hi Lee - i've only seen cinnamon come from tree bark - not roots - so that's interesting. Anytime you're working with a raw agricultural product, but it from above the ground or below, there's a risk of unsavory microbiological elements. Bacteria will not grow in chocolate, but may remain viable, and yes, chocolate is a terrible oxygen barrier, but that's not really important for this. Usually cinnamon is steam sterilized prior to use to ensure a low(er) micro count, but even then spices are notoriously high in micro load. If i was making it for personal use and consumption i'd be less concerned about it, if i was making for my business and others to consume, i'd pay far more attention to it.

In terms of botulism, whether chocolate contains / is a barrier for oxygen is critical in my view. Botulism only becomes a health hazard when the related bacteria find themselves in an anaerobic, low-acid environment. So if the interior of a piece of dark chocolate is low oxygen and no new oxygen can get it, the bacteria can quickly use up the available oxygen and begin producing botulinum toxin.

However you are saying chocolate is not a barrier for oxygen. How do you know this? I'm not doubting you here, just curious to know where I might find more detailed information.

As to other bacteria, of course there are always concerns, although it's my understanding as well that chocolate is by and large an inhospitable environment for most things, hence the 2-year shelf life. Again, could be mistaken! Your mention of steam sterilization is very useful though, thanks. I'll look into that further.

C. Botulinum - the organism responsible for the botulinum toxin - requires a VERY high water activity - well over 0.7 (many say as high as 0.95). Chocolate has a water activity somewhere in the 0.1-0.25 range. There's not nearly sufficient water activity for any organism to vegetate, i'm afraid. C Botulinum is an anaerobic spore former, and spores of course will remain viable for very long periods of time, but the toxin is only produced when the organism is in it's vegetative (i.e. growing and reproducing state). It doesn't matter how much oxygen can penetrate the chocolate if there's insufficient water for the organism to grow. It's a bit like saying humans require oxygen to live - which is true - but if there's no water in your environment, it similarly doesn't matter how much oxygen is present...

I know this as i've led global chocolate research for decades. The high oxygen permittivity of chocolate surprises most people.

It's surprising indeed! I'm not surprised about the water activity, however. So it looks like between lack of water and presence of oxygen, I'm ok in terms of botulism. On to steaming...

Thanks Sebastian!

Thanks to both of you! I greatly value your scientific perspective.

I agree that microbes from the cinnamon will not grow within the chocolate due to its low water activity. But since the cinnamon comes in form of inclusions, it's maybe more relevant what water activity the cinnamon has. If it is in dried form (like cinnamon mostly is when we use it as spices), everything should be fine.
I would only worry about C. Botulinum when using inclusions of high water activity.

Ah ha, well caught! The cinnamon was air dried at ~70C for 24 hours while in a rough powder form. so I'm thinking it will be very low H2O by now.

Thanks for raising that point!