An unknowing parcel delivery guy has handed over this early christmas present to me:
View attachment 63165
Per the
article description, it is canola oil, partially hydrogenated to an iodine value of 45–55.
Yes! Finally some numbers to work with
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My first impulse was to ask the manufacturer if they wouldn't have a GC analysis/FA profile to share with me. On the other hand, as long as we have only a rough conception how really the elaidic acid works (wrt soap hardness), a precise profile isn't too helpful anyway – we wouldn't gain much beyond guesstimates.
So, let's guesstimate on our own!
We can get this interesting graphic from
this publication:
Composition change of canola oil during hydrogenation. Unfortunately C18:1 isn't further broken down to oleic/elaidic. But we see the IV go down from about 120 to 50 (stars in the right panel) – exactly where OBW073 is located! At that 360 minute mark, on the left, we see that we can expect next to zero remaining PUFAs as well as about
40% stearic acid.
Now, in contact with hydrogenation catalysts, there is an equilibrium between oleic and elaidic acid. How this looks exactly is tricky to estimate (and depends on everything: reaction conditions, catalysts and time in particular). The best I could find on the quick was
this paper. They however stop too early at IV ≈ 70. But the trend they see is that elaidic levels rise about twice as fast as the stearic (which is of limited use in the IV regions we're looking at). I loosely remember that, in equilibrium, cis-trans isomerisation favours the trans variant by somewhere 2:1…5:1.
Once again, exact values aren't even particularly helpful as long as we don't know how to treat elaidic acid in terms of its properties. It is evident that it is “harder” than oleic acid, but on the other hand it's also less hardening than stearic acid.
This is, for now, my approach to this situation: I theoretically divide the C18:1 part 2:1 into 40% elaidic and 20% oleic acid. I also assume that elaidic acid is about half the way between oleic and stearic acid, i. e. 2 g elaidic acid contribute to hardness/longevity/creamy numbers like 1 g stearic acid. For this canola wax, I end up with a working hypothesis of effective 60% stearic acid content.
How convenient that there is an oil in
soap calculators that matches these properties quite well!
Kokum butter is listed with 56% stearic (close enough to my guesstimate), 4% palmitic (exactly as canola), and the remainder nearly pure oleic acid. IV and INS are, of course, off the chart. The SAP is 0.135, a tiny bit too high for the 0.133 of canola oil, but reasonably close to offset with some 0.5% superfat discount (at typical usage rates). The melting range of kokum butter (37–40°C) is quite a bit lower than the specification of the OBW073 (47–54°C); we'll see how this pans out, especially in oil blends. Anyway, a reminder for the annoyances of false trace can never be wrong
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Needless to say that I will keep you well supplied with updates how the OBW073 is performing!
)
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). Even then, they were just barely hard enough to not entirely lose their shape.
