# USDA says High Fructose Corn Syrup is mostly starch? **URL:** \ **Category:** Factual Questions\ **Created:** [November 29, 2011, 2:35am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408 "2011-11-29T02:35:15Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [November 29, 2011, 2:35am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/1 "2011-11-29T02:35:15Z")
This is weird. I went to the USDA’s Nutrient Data Laboratory webpage, at [DRI Calculator for Healthcare Professionals | National Agricultural Library](http://www.nal.usda.gov/fnic/foodcomp/search/). I entered “corn syrup” in the Keywords field, and selected “Sweets” in the Select Food Group droplist. On the next page, I selected “Syrups, corn, high-fructose”. On the next page, I selected 1 tbsp. as the serving size. The page that came up said this: > [@](#): > > Carbohydrate, by difference: 14.44g > Fiber, total dietary: 0.0g > Sugars, total: 5.01g So 14.44 total grams of carbohydrate, but only 5.01 grams of sugar? Does that mean that 9.43 grams of every tablespoon of High Fructose Corn Syrup is … _ **starch?!** _ That can’t be right. Every article I’ve read about High Fructose Corn Syrup says it’s 55% fructose and 45% glucose. What’s going on here?! ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [November 29, 2011, 2:51am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/2 "2011-11-29T02:51:02Z")
What do you think starch is, if not polymerized sugars like fructose and glucose? (C6H10O5)n is the basic formula for starch. Fructose and glucose are both C6H12O6. Link two of them in a row and you’ve got starch. HFCS is made by taking corn starch, breaking a lot of it down into glucose, then converting some of it to fructose with enzymes. But a lot of complex starch molecules remain. ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [November 29, 2011, 2:58am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/3 "2011-11-29T02:58:09Z")
> [@Qadgop\_the\_Mercotan](#): > > HFCS is made by taking corn starch, breaking it down into glucose, then converting some of it to fructose with enzymes. But a lot of complex starch molecules remain. But it was my understanding that by the time it left the factory, _all_ (or nearly all) of that starch had been broken down. This USDA page makes it sound like half the cornstarch isn’t even touched by the refining process – which flies in the face of the [Nutrition Facts label for American Coca-Cola](http://productnutrition.thecoca-colacompany.com/products/coca-cola). It’s sweetened exclusively with High Fructose Corn syrup, and _ **all** _ of its carbohydrates are in the form of sugars. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 29, 2011, 4:21am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/4 "2011-11-29T04:21:27Z")
Interesting. I would have thought that the breakdown process would have converted a much higher percentage of the corn starch to simple sugars. That would make it the equivalent of honey, which has almost all the carbohydrate accounted for as sugars. > [@](#): > > Carbohydrate, by difference 1 tsp > 17.30 g > > Sugars, total > 17.25 g > > Sucrose > 0.19 g > > Glucose (dextrose) > 7.51 g > > Fructose > 8.60 g > > Maltose > 0.30 g > > Galactose > 0.65 g I can’t find any information about the way the USDA defines sugars or carbohydrates for their purposes, and that seems to be the underlying issue. I can’t think of any processing reason why the sugars are treated this way, though. Wikipedia gives the process: > [@](#): > > 1. Cornstarch is treated with alpha-amylase to produce shorter chains of sugars called oligosaccharides. > 2. Glucoamylase - which is produced by Aspergillus, species of mold, in a fermentation vat — breaks the sugar chains down even further to yield the simple sugar glucose. > 3. Xylose isomerase (aka glucose isomerase) converts glucose to a mixture of about 42% fructose and 50–52% glucose with some other sugars mixed in. Normally oligosaccharides are treated as starch and the mono- and di-saccharides are given as sugars. Both glucose and fructose are monosaccharides. HFCS should be all-sugar by that definition, as on the Coke label. While the discrepancy is startling at first glance, I have to believe it’s some arcane definitional issue. Leaving more than half the product incompletely processed seems too unlikely to be reasonable. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 29, 2011, 4:26am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/5 "2011-11-29T04:26:25Z")
> [@Qadgop\_the\_Mercotan](#): > > What do you think starch is, if not polymerized sugars like fructose and glucose? > > (C6H10O5)n is the basic formula for starch. Fructose and glucose are both C6H12O6. Link two of them in a row and you’ve got starch. Link _two_ of them in a row and you have got [sucrose](http://en.wikipedia.org/wiki/Sucrose), which is still sugar, the last I heard. It is the actual stuff that you can buy in the supermarket marked as sugar. The thing is, there can be pretty much as many links in the polymer as you like. One or two and you still have a sugar. Many, and you have a starch, but [actual starch is, pretty much by definition, insoluble](http://en.wikipedia.org/wiki/Starch), so it can’t really be a component of syrup. However, there are points in between. If the information that **tracer** is getting from the USDA site is correct then the missing carbohydrate is probably [dextrins](http://en.wikipedia.org/wiki/Dextrin), oligosaccharides, polymer chains of sugar units that are still short enough to be soluble (and to taste sweet, generally), but not long enough to be insoluble starches. They are probably also what give the syrup that nice golden color. ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [November 29, 2011, 8:46am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/6 "2011-11-29T08:46:03Z")
Two minor nitpicks: 1. Last I checked, there’s no fructose in starch. Starch is composed entirely of glucose units. 2. Two glucose units linked together is called _maltose_. (Three is called _maltotriose_.) Maltose is still considered a sugar. It gets its name from its presence in beer. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 29, 2011, 11:48am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/7 "2011-11-29T11:48:49Z")
> [@tracer](#): > > Two minor nitpicks: > > 1. Last I checked, there’s no fructose in starch. Starch is composed entirely of glucose units. > > 2. Two glucose units linked together is called _maltose_. (Three is called _maltotriose_.) Maltose is still considered a sugar. It gets its name from its presence in beer. I am not sure who you think you are nitpicking at, but this in no way contradicts anything I said. Note that my first paragraph was in reply to **Qadgop**. The answer to your original question is still **dextrins**. You’re welcome. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 29, 2011, 4:40pm UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/8 "2011-11-29T16:40:50Z")
Do dectrins exist? Obviously. Does corn syrup contain dextrins? Yes. Neither of those are the question. The question is whether HFCS, after processing, contains more than 50% dextrins, since that is exactly what the processing is designed to break down. I can’t find any evidence of that. If you think dextrins are the answer, then please show some evidence that they remain in the final product, HFCS, and to what percentage. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [November 29, 2011, 8:15pm UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/9 "2011-11-29T20:15:37Z")
> [@Qadgop\_the\_Mercotan](#): > > What do you think starch is, if not polymerized sugars like fructose and glucose? > > (C6H10O5)n is the basic formula for starch. Fructose and glucose are both C6H12O6. Link two of them in a row and you’ve got starch. > > HFCS is made by taking corn starch, breaking a lot of it down into glucose, then converting some of it to fructose with enzymes. But a lot of complex starch molecules remain. Can’t we just go buy it in the store? I tell you, the glassware bill for the kitchen would be unholy if we needed to get labware…:dubious:😃 ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [November 29, 2011, 9:13pm UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/10 "2011-11-29T21:13:11Z")
> [@Exapno\_Mapcase](#): > > I can’t find any information about the way the USDA defines sugars or carbohydrates for their purposes, and that seems to be the underlying issue. I can’t think of any processing reason why the sugars are treated this way, though. The “documentation” link on the front page leads to [url=]this PDF, which states on page 11 that: > [@](#): > > Carbohydrate, when present, is determined as the difference between 100 and the sum of the percentages of water, protein, total lipid (fat), ash, and, when present, alcohol. … Total sugars is the term used for the sum of the individual monosaccharides (galactose, glucose, and fructose) and disaccharides (sucrose, lactose, and maltose). Analytical data for individual sugars obtained through NFNAP were determined by liquid chromatography (AOAC 982.14). Earlier values were also determined using AOAC methods (2010), with either high-performance liquid chromatography (HPLC) or gas-liquid chromatography (GLC). When analytical data for total sugars are unavailable for items in the FNDDS, values are imputed or obtained from manufacturers and trade associations. … Because the analyses of total dietary fiber, total sugars, and starch are performed separately and reflect the analytical variability inherent to the measurement process, the sum of these carbohydrate fractions may not equal the carbohydrate-by-difference value. But I’m as flummoxed as you about why the discrepancy seems to be so large in this case. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [November 29, 2011, 9:32pm UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/11 "2011-11-29T21:32:10Z")
For comparison, [this article](http://pubs.acs.org/doi/pdf/10.1021/jf100758x) (subscription may be required) finds the total glucose & fructose fraction of HFCS to range from 700-800 milligrams per gram of syrup, depending on what type of HFCS you’re talking about. So something’s definitely at odds here. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 29, 2011, 10:04pm UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/12 "2011-11-29T22:04:04Z")
> [@Exapno\_Mapcase](#): > > Do dectrins exist? Obviously. Does corn syrup contain dextrins? Yes. > > Neither of those are the question. The question is whether HFCS, after processing, contains more than 50% dextrins, since that is exactly what the processing is designed to break down. > > I can’t find any evidence of that. > > If you think dextrins are the answer, then please show some evidence that they remain in the final product, HFCS, and to what percentage. The only other carbohydrates that exist are either sugars or insoluble starches. (And cellulose, I guess, but that is not relevant here. There is no fiber.) Dextrins are soluble carbohydrates that are not, technically, sugars. They are the only possible candidates to make up this discrepancy. When you have eliminated the impossible, whatever remains, however improbable, must be the truth. (And this is not even improbable. Indeed, the hydrolyzation of starch is bound to produce dextrins along the way, and they are bound to be present in the product if you do not deliberately hydrolyze everything all the way to 100% sugar.) The only other possibility is that the figures obtained by **tracer** are just wrong. I do not rule this out, indeed I allowed for it in my original post, but if we assume that the figures are right (and that “carbohydrate” actually means carbohydrate) the discrepancy has got to be (and it perfectly well could be) made up by dextrins. Dextrins tend to taste kind of nice too, a bit more interesting than the pure sweetness of sugars, and they will make the syrup more viscous and syrupy. It makes sense that the manufacturers might want to keep the dextrin content fairly high. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [November 29, 2011, 10:54pm UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/13 "2011-11-29T22:54:45Z")
> [@MikeS](#): > > For comparison, [this article](http://pubs.acs.org/doi/pdf/10.1021/jf100758x) (subscription may be required) finds the total glucose & fructose fraction of HFCS to range from 700-800 milligrams per gram of syrup, depending on what type of HFCS you’re talking about. So something’s definitely at odds here. Well, I whiffed then. No idea. ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [November 30, 2011, 12:09am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/14 "2011-11-30T00:09:33Z")
> [@njtt](#): > > The only other possibility is that the figures obtained by **tracer** are just wrong. That’s the direction I’m kind of leaning, too. What brought this whole mess up in the first place was that someone, on a website that has nothing to do with chemistry or nutrition, claimed he read in an article somewhere that “HFCS is actually closer to a starch” than it is to a sugar (with a link to a page that got its nutrition data from the USDA site I mentioned in the OP), and that this means “your body holds it for longer, up to 3 days according to one report”. He didn’t say the name of this “one report”, and the website wasn’t set up to allow conversations or back-and-forth posts between one person and another. I’m wondering if this “one report” he’s talking about was some guy’s rant after reading the USDA’s Nutrition Facts entry for HFCS and jumping to his own conclusions. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 30, 2011, 12:16am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/15 "2011-11-30T00:16:29Z")
> [@njtt](#): > > When you have eliminated the impossible, whatever remains, however improbable, must be the truth. As many people have noted, this was sheer gibbering imbecility when Doyle wrote it, and it hasn’t gotten any better over time. > [@](#): > > Dextrins tend to taste kind of nice too, a bit more interesting than the pure sweetness of sugars, and they will make the syrup more viscous and syrupy. It makes sense that the manufacturers might want to keep the dextrin content fairly high. Corn syrup is distinctly less sweet than sucrose and also less sweet than HFCS, which is designed to be about as sweet as sucrose. Having a high dextrin content is the absolute opposite of what manufacturers want to do. HFCS is about a quarter water, so manifestly the glucose/fructose fraction will be about 750 mg per gram. And that leaves no room for dextrins, does it? tracer, I found that “fact” about HFCS on [tvtropes](http://tvtropes.org/pmwiki/pmwiki.php/Main/UnfortunateIngredients), and I bet it needs a citation. :rolleyes: ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [November 30, 2011, 12:46am UTC](https://boards.straightdope.com/t/usda-says-high-fructose-corn-syrup-is-mostly-starch/604408/16 "2011-11-30T00:46:00Z")
> [@Exapno\_Mapcase](#): > > tracer, I found that “fact” about HFCS on [tvtropes](http://tvtropes.org/pmwiki/pmwiki.php/Main/UnfortunateIngredients), and I bet it needs a citation. :rolleyes: If you look at the history for that TV Tropes page, you’ll note a certain familiar username associated with the edit earlier today, in which a cutesy “[citation needed]” superscript was added. 😉