That’s in line with the latest theory about maximizing carb absorption. I’m avoiding the “fructose component of sucrose” and using maltodextrin because of the unproven thought that fructose is going to kill you. But the current data says you’re doing it right.
Joe
Thanks Joe - this is a good point. The question of “what is good for a human to consume” and “what should I consume to maximize carb absorption during exercise” are two completely different questions, and I have been mainly focused on the latter regarding this topic. I do try (when I am being good diet wise) to minimize my off the bike sugar, but I have not been looking at fructose vs. glucose other than absorption rates. For the off the bike stuff, I really ‘should’ be having low refined sugar intake that I’m not worrying about the type. (If only I always did what I should do 
)
I also do prefer the non-sweet taste of maltodextrin - a 10% sucrose solution is very, very sweet.
I’m mixing up two 20oz bottles with 210g of sugar in each (1 cup by volume) for tomorrows ride so I know exactly what you mean! I’ll drink water from the hydration pack but still!!
A sucrose solution is not quite the ideal way to maximize carb absorption. Maltodextrin is used not to reduce fructose, but because the higher molecular weight keeps the molarity of the solution 5x10 times lower than an equal weight of sucrose. This allows for easier gut emptying and then absorption. Some “complex” carb sources have a higher glycemic index than glucose alone, and I’d suspect this is the main reason.
Your 10% solution is 290 mmol and may now be hypertonic, thus your stomach would pull water in from your body before it can clear your gut. So a 5-7% solution would be a bit better for when it gets warmer and you are losing water from sweat, thus making it harder to absorb a hypertonic solution. Studies have shown a hypotonic solution, which means lower concentration than the 250-290 mmol of our bodies is cleared faster by the gut. Malto, depending on how many glucose molucules are in the polymer makes it much easier to go hypotonic.
Is there any data on optimal osmolarity for absorption? Is lower better…like is cool water absorbed fastest?
Joe
If you can read in German this is a good paper:
Trinken im Sport
I can’t find peer reviewed sources right now, but it would appear that solutions with lower concentration than blood are absorbed faster but i havent seen any hard or fast numbers. The main deal i was trying to address was stomach comfort during exercise.
Fair point - I have not tried this in really hot weather, and would likely add water in those cases. I would likely need more water in those situations than I could consume at 10% without overloading on carbs.
I may try some experiments this summer to see how I tolerate the higher concentrations for multiple hours.
Regarding osmolarity, what you describe is clearly the case when just looking at maltodextrin alone.
For the 0.8/1.0 fructose/glucose ratios, it seems that the osmolarity is similar between these and sucrose, as in those cases the fructose molecules are individual. It would seem to me that for fructose/glucose mixes that sucrose + malto would get you the same or lower osmolarity that fructose+malto. (There may be taste reasons to prefer fructose+malto.)
I’m not generally pushing things where a 10% difference in osmolarity or carbs/hour is critical, so I’m willing to use a much cheaper and simpler formula that gets me 90% there. If/when I do try to push the limit, I would likely just add malto to sucrose to tweak the sugar ratios.
i’ve been doing the 25#s of fructose from nuts.com and 50#s of malto from local brewing supply store for the last 18 months.
I just decant everything into workable containers for everyday use and storage. Have a couple of (I think rubbermaid brand) resealable containers with wide mouth so that dont get a big mess opening/closing and resealing. They also pack away nicely in the cupboard.
Sucrose + malto should be a perfectly suitable alternative to buying fructose and would have similar osmo to a malto + fructose mix. It really depends on the molecular weight of the malto.
I’m curious about how suitable brewers malto is for this situation, since it is chosen specifically for the undigestable dextrins to give a beer better mouthfeel and body. All seem to come from corn though, so not sure on that part.
Ugh, and now my old supplier of malto is no longer selling through Amazon, and wants $30 to ship 3 lb. time to find a new supplier…
I posted a question about molecular weight for the “somewhat commonly used malto” https://www.amazon.com/gp/product/B0013OUNRM/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
there was also this…but I’m not sure what it means…does “dextrose equivalent” help with determining osmolarity (I’m guessing not but don’t know)
Q: What is the DE (dextrose equivalent) value of this maltodextrin? I need the exact value, not a link explaining what maltodextrin is, thanks!
A: The specified range is 9% to 12%; our most recent batches were tested at 11.68, 11.65, 11.78, 11.39 so we would expect it to be typically between 11-12%.
I’d like to get a recipe for adding maltodextrin to skratch…sorta shooting for “skratch plus” if that makes any sense.
Joe
It’s not the length, but the type of bonds that determines digestibility. Starch and fiber are both long chain glucose polymers, but one is very easily digested while the other not. I’m just mostly curious if the claims about the remaining dextrins after fermentation also not being digestable.
The length is going to have a big impact on the osmo of the prepared drink mix.
I think you can estimate by dividing the de in to 100, so 11 or 12 means approximately 8 or 9 glucose molecules per malto molecules. So 25% the osmo of sucrose.
Yeah…I’ve been there too and corrected myself here (still unsure about all that DE marketing):
Origin point of that discussion was
You can get a 5kg (11lb imperial) bag of Maltodextrin for £8.74 here in the UK.
That seems to be the price at MyProtein?
Bulkpowders is a few pence more, but out of stock (as it seems just about everything is these days)
That’s the one. Some other companies add flavouring to Maltodextrin which kind of defeats the object of using it. If I can taste anything in my water I find I don’t tolerate it more than a few hours. Unflavoured I can just keep drinking and drinking hour after hour.
Just wanted to share that the ebay store also offers a 50lb bag of Fructose
It looks like its just at $5.19 per pound when purchasing at this quantity.
I don’t question our ability to digest malto, but other dextrins which might be present. Sorry if i didn’t clearly say that as i might skip through some details when posting by phone. The first article i looked up about dextrins and brewing made a dubious claim about the remaining dextrins in beer as having no calorie content. Although there are dextrins used in the food industry as fiber sources, the ones in beer are not. I had thought that wasn’t the case since i’ve done a bit of brewing and you can manipulate the unfermentable sugars by using darker malts or higher temps to deactivate alpha amylase. But those are definitely adding to the overall calorie content. So my main wonder was if the product was not pure maltodextrin.