I am looking for a source about the gluten contents in foods and beverages. I'm not gluten-intolerant and I don't have any allergy of any kind. But I'm working on this diet and I am just wondering if there are sources that can show me how much gluten is in different foods. I've scoured the internet for sources, to no avail. I see friends of mine also struggling with this same question.
On an elementary level, only very few grains of grasses do contain the protein complexes of the gluten group: Gliadin in Wheat, Hordein in Barley, Secalin in Rye, Avenin in Oats. On a 'processed' level gluten can be in a lot of products.
If experiencing gluten intolerance symptoms, the products on this page should be avoided. Instead, concentrate on gluten free, brain healthy foods. Many are listed here. This is sure to help maintain or improve brain health and function.
The following grains and starches contain gluten:
Wheat, Wheat germ, Rye, Barley, Bulgur, Couscous, Farina, Graham flour, Kamut, Matzo, Semolina, Spelt, Triticale
The following foods often contain gluten:
malt/malt flavoring, soups, commercial bullion and broths, cold cuts, French fries (often dusted with flour before freezing), processed cheese (e.g., Velveeta), mayonnaise, ketchup, malt vinegar, soy sauce and teriyaki sauces, salad dressings, imitation crab meat, bacon, etc, egg substitute, tabbouleh, sausage, non-dairy creamer, fried vegetables/tempura, gravy, marinades, canned baked beans, cereals, commercially prepared chocolate milk, breaded foods, fruit fillings and puddings, hot dogs, ice cream, root beer, energy bars, trail mix, syrups, seitan, wheatgrass, instant hot drinks, flavored coffees and teas blue cheeses, vodka, wine coolers, meatballs, meatloaf communion wafers, veggie burgers, roasted nuts, beer, oats (unless certified GF), oat bran (unless certified GF),
The following are miscellaneous sources of gluten:
shampoos, cosmetics, lipsticks, lip balm, Play-Doh, medications, non self-adhesive stamps and envelopes, vitamins and supplements (check label),
The following ingredients are often code for gluten:
Avena sativa Cyclodextrin, Dextrin, Fermented grain extract, Hordeum distichon, Hordeum vulgare, Hydrolysate, Hydrolyzed malt extract, Hydrolyzed vegetable protein, Maltodextrin, Phytosphingosine extract, Samino peptide complex, Secale cereale, Triticum aestivum, Triticum vulgare, Tocopherol/vitamin E, Yeast extract, Natural flavoring, Brown rice syrup, Modified food starch, Hydrolyzed soy protein, Caramel color (frequently made from barley)
David Perlmutter: "Gluten Containing Products"
That is a long list to observe. And fortunately, that is only really necessary to observe strictly for celiac disease and allergies. For other reasons of observing gluten reduction we have to observe contradictory findings:
In conclusion, our results indicate that for GF foods no predominant health benefits are indicated; in fact, some critical nutrients must be considered when being on a GF diet. For individuals with celiac disease, the GF database provides a helpful tool to identify the food composition of their medical diet. For healthy consumers, replacing gluten-containing products with GF foods is aligned with substantial cost differences but GF foods do not provide additional health benefits from a nutritional perspective.
Benjamin Missbach et al.: "Gluten-free food database: the nutritional quality and cost of packaged gluten-free foods", PeerJv.3; 2015, PMC4627916, DOI
On the other hand, practitioners seem to find – just like laypersons, trying it out – surprising improvements not by elimination of gluten, but by reducing gluten consumption. It's theorised that it's in this case not about the gluten, but accompanying substances called amylase-trypsin-inhibitors. These are quite understudied at the moment.
Diagnostically, a differential between celiac (blood: anti-TG2, anti-DGP-antibodies), wheat allergy (blood: IgE-Ak), ATI-sensivity (no blood markers yet, but decline of chronic conditions), and FODMAP-intolerance has to be made.
Detlef Schuppan & Kristin Gisbert-Schuppan: "Tägliches Brot: Krank durch Weizen, Gluten und ATI", Springer: Berlin, 2018. (DOI)
If the aim of this inquiry is this 'reduction' in typical diets, than it is not really necessary to avoid gluten entirely in the long term.
Nevertheless, the interest in these diets makes exact sources less important for non-celiac, non-allergy applications.
And more important: they can vary a lot.
Gluten in bread wheat is also much higher than in durum wheat for pasta.
Edurne Simón et al.: "Nutritional and Analytical Approaches of Gluten-Free Diet in Celiac Disease", SpringerBriefs in Food, Health, and Nutrition, Springer: Cham, 2017.
Dependence of specific bread volume on the content of glutenin macropolymer (GMP) in flours from various wheat cultivars (modified from Thanhaeuser SM, Wieser H, Koehler P (2014) Correlation of quality parameters with the baking performance of wheat flours. Cereal Chem 91: 333–341) statistical test procedure: Pearson correlation
GMP = glutenin macropolymer, p = significance, r = correlation coefficient
Katharina Anne Scherf & Peter Köhler: "Wheat and gluten: Technological and health aspects", Ernahrungs Umschau 63(08): 166–175, 2016. DOI: 10.4455/eu.2016.035. (PDF)
For a better overview of gluten problems and possible associated problems: Hetty C van den Broeck et al.: "Wheat and Gluten Intolerance. An overview of the latest scientific insights and possible solutions for the bakery sector", ICC, March 2016. (PDF)
The want to get more precise numbers is understandable, but probably will be misleading for actual application on the individual level. Due to the level of variation, if not given on a label of a concrete product, it will be giving the illusion of precision in an area of probably low importance where jst rough guides would suffice.
To illustrate this, actual measurements from beer:
Malt type Gluten (g kg^–1)a,c Caraaroma (barley) 42.0 ± 0.2 Melanoid (barley) 20.4 ± 0.2 Cararred (barley) 20.6 ± 0.2 Carafa (barley) 45.0 ± 0.2 Pilsner (barley) 18.8 ± 0.6 Smoked (barley) 20.8 ± 1.0 Munich (barley) 20.2 ± 0.2 Wheat chocolate (Wheat)b 44.0 ± 1.6 Wheat pale (Wheat)b 68.0 ± 4.0 Spelt chocolate (Spelt) 21.2 ± 0.4 Rye chocolate (Rye) 41.6 ± 1.4
a Mean ± standard deviation (n=3). b Sample analysed by Gliadin ELISA kit. c All samples, except wheat, were analysed by RIDASCREENÕ Gliadin kit.
Gluten balance during brewing process Product Gluten (mg/kg^-1) (%) Malt 18780 100 Sweet wort 49.4 1.75 Wort 48 1.70 Beer 6.0 0.21 Stabilised beer <3.0 <0.11
Gluten content in malt represents 100%. bAll samples were analysed by RIDASCREENÕ Gliadin kit.
P. Dostálek , I. Hochel , E. Méndez , A. Hernando & D. Gabrovská: "Immunochemical determination of gluten in malts and beers", Food Additives & Contaminants, Volume 23, 2006 - Issue 11, p1074-1078. DOI
While it may be the better approach for 'reducing gluten' to just choose certified gluten-free for y number of foods in x situations, one my be serious about this and compare The gluten composition of more than 8,500 wheat varieties is provided in two new databases.