Sources & methodology

Where our intolerance data comes from — and why you can trust it.

Wondering whether you can trust these ratings? Every intolerance level comes from published, peer-reviewed science — studies that actually measured how much of each compound (histamine, salicylates, FODMAPs, nickel…) is in real foods, not from guesswork. Here's exactly where the data comes from, and how we handle uncertainty.

Peer-reviewed science — measured food content, not default guesses.
Cautious when unsure — missing data means we flag, not reassure.
Independently sourced — built from the primary literature we cite.

Marks say how far we got into a reference, because a tick that means the same thing for a whole paper and for an abstract says nothing at all. What was checked in each one is recorded in the repository.

read in full, tables included
read in part — a results section, a composition table, the annex of a regulation
abstract or catalogue record only
cited by a note, not yet reopened

FODMAPs, fructose, sorbitol, sucrose

FODMAP content varies by food and ripeness, so we use studies that measured fructans, polyols and sugars in specific foods.

Mikulic-Petkovsek M. et al. (2012). Composition of sugars, organic acids and total phenolics in 25 wild or cultivated berry species — glucose and fructose the dominant sugars, and sorbitol detected and quantified in chokeberry, rowanberry and eastern shadbush alone. Journal of Food Science 77(10), C1064–C1070.
Tuck C. et al. (2018). FODMAP content of common plant-based and processed foods. Journal of Human Nutrition and Dietetics.
Perovic J. et al. (2021). Chicory (Cichorium intybus L.) as a food ingredient — leaf fructans near 0.1 % of fresh weight against 15–20 % in the root. Food Chemistry 339.
Yao C.K. et al. Dietary sorbitol and mannitol: food content and absorption patterns. Journal of Human Nutrition and Dietetics.
Ma C. et al. (2014). Fructose, sorbitol, glucose and sucrose in fruits by HPLC-ELSD. Food Chemistry.
Lenhart A. et al. (2017). Polyols and gastrointestinal health / IBS: a systematic review. Advances in Nutrition.
L'homme C. et al. (2001). Fructans in fresh and stewed fruits (HPAEC-PAD). Journal of Chromatography A.
Zumbé A. et al. (2001). Polyols in confectionery — sugar-free and reduced-calorie products. British Journal of Nutrition.
Hughes A. et al. (1985). Sugars and mannitol in cabbage and fermenting sauerkraut. Journal of Food Science.
Hogarth A.J. et al. (2000). Ion chromatographic determination of three fructooligosaccharide oligomers in prepared and preserved foods — of the vegetables investigated, artichokes contained by far the most FOS, followed by onions. Journal of Agricultural and Food Chemistry 48, 5326–5330. doi:10.1021/jf000111h
Moshfegh A. et al. (1999). Inulin and oligofructose in the diets of Americans. Journal of Nutrition.
Rakha A. et al. (2010). Dietary fibre components in rye products. Food Chemistry.
Nemeth C. et al. (2014). Grain fructan content and degree of polymerisation in barleys. Food and Nutrition Sciences.
Vidal-Valverde C. et al. (2003). Nutritional and antinutritional compounds in pea seeds. Journal of the Science of Food and Agriculture.
Böhm A. et al. (2005). Heat-induced degradation of inulin. European Food Research and Technology.
Hebestreit K. et al. (2015). Das FODMAP-Konzept — Empfehlungen für die Ernährungsberatung. Aktuelle Ernährungsmedizin.
Helwig U. et al. (2019). Predictive value of the hydrogen breath test in fructose malabsorption. Digestion.
Muir J. et al. (2007). Fructan and free fructose content of common Australian vegetables and fruit. Journal of Agricultural and Food Chemistry.
Muir J. et al. (2009). Measurement of short-chain carbohydrates in common Australian vegetables and fruits by HPLC. Journal of Agricultural and Food Chemistry.
Biesiekierski J. et al. (2011). Quantification of fructans, galacto-oligosaccharides and other short-chain carbohydrates in processed grains and cereals. Journal of Human Nutrition and Dietetics.
Campbell J.M. et al. (1997). Selected fructooligosaccharide (1-kestose, nystose, 1F-β-fructofuranosylnystose) composition of foods and feeds — the Compositae highest in total FOS, then the Allium species. Journal of Agricultural and Food Chemistry 45, 3076–3082. doi:10.1021/jf970087g
Prichard R. et al. (2016). FODMAP content of foods commonly consumed by ethnic minority groups in the United Kingdom. International Journal of Food Sciences and Nutrition.
Jiang G.-L. et al. (2020). Analysis and comparison of seed protein, oil, and sugars in edamame dried using two oven-drying methods and mature soybeans — mature soybean highest in stachyose and total sugars, then unshelled-dried, then shelled-dried edamame. Journal of the Science of Food and Agriculture 100, 3987–3994. doi:10.1002/jsfa.10443
Espinosa-Martos I. et al. (2005). Low molecular weight carbohydrates in foods usually consumed in Spain. Food Science and Technology International.
Jovanovic-Malinovska R. et al. (2014). Oligosaccharide profile in fruits and vegetables as sources of prebiotics. International Journal of Food Properties.
Jaime L. et al. (2001). Effect of storage on fructan and fructooligosaccharide of onion — five varieties, the shortest oligomer the major one, and free fructose rising as the fructans hydrolyse in store. Journal of Agricultural and Food Chemistry 49(2), 982–988.
Kaack K. et al. (2004). Non-structural carbohydrates in processed soft fried onion. European Food Research and Technology.
Lisciani S. et al. (2017). Carbohydrate components of Italian garlic landraces (Allium sativum L.). Sustainability.
Zhang N. et al. (2013). Prebiotic effectiveness of neutral garlic fructan in vitro. Food Science and Human Wellness.
Whelan K. et al. (2011). Fructan content of commonly consumed wheat, rye and gluten-free breads — 0.61–1.94 g/100 g, gluten-free no lower than wheat. International Journal of Food Sciences and Nutrition.
Verspreet J. et al. (2015). Cereal grain fructans — structure, variability and potential health effects. Trends in Food Science & Technology.
Shewry P. et al. (2015). Do ancient wheat species differ from modern bread wheat in their contents of bioactive components? Journal of Cereal Science.
Reddy N. et al. (1984). Chemical, nutritional and physiological aspects of dry bean carbohydrates — a review. Food Chemistry.
Wang N. et al. (2010). Effect of cooking on the composition of beans and chickpeas. Food Research International.
Švejstil R. et al. (2015). Raffinose-series oligosaccharides in soybean products. Scientia Agriculturae Bohemica.
Jones D. et al. (1999). Compositional variation for the raffinose family of oligosaccharides in pea seeds. Seed Science Research.
Bryant R. et al. (2003). Galactosidase activities and oligosaccharide content in peanuts. Plant Foods for Human Nutrition.
Ruiz-Terán F. et al. (1999). Fate of oligosaccharides during production of soya bean tempe. Journal of the Science of Food and Agriculture.
Rehms H. & Barz W. (1995). Degradation of stachyose, raffinose, melibiose and sucrose by different tempe-producing Rhizopus fungi. Applied Microbiology and Biotechnology 44, 47–52. doi:10.1007/BF00164479
Schütz K. et al. (2006). Inulin in artichoke cultivars and dandelion roots (HPAEC-PAD). Biomedical Chromatography.
Shiomi N. et al. (2007). Saccharide and fructooligosaccharide contents of green asparagus spears during storage. Journal of Applied Glycoscience.
Wennberg M. et al. (2006). Changes in carbohydrate composition of white cabbage during blanching. Food Chemistry.
Thavarajah D. et al. (2016). Prebiotic carbohydrate profiles of kale. Journal of Food Composition and Analysis.
Nogueira L. et al. (2005). Separation and quantification of beer carbohydrates by HPLC-ELSD. Journal of Chromatography A.
Mäkinen K. (2016). Gastrointestinal disturbances associated with the consumption of sugar alcohols, with special consideration of xylitol. International Journal of Dentistry.
Storey D. et al. (2007). Gastrointestinal tolerance of erythritol and xylitol ingested in a liquid. European Journal of Clinical Nutrition.
Lee J. (2015). Sorbitol, Rubus fruit, and misconception. Food Chemistry.
Stoop J. et al. (1996). Mannitol metabolism in plants — a method for coping with stress. Trends in Plant Science.
Beluhan S. et al. (2011). Chemical composition and non-volatile components of Croatian wild edible mushrooms. Food Chemistry.
Gibson P.R. & Shepherd S.J. (2010). Evidence-based dietary management of functional gastrointestinal symptoms: the FODMAP approach — the framework defining FODMAPs as poorly absorbed, rapidly fermented short-chain carbohydrates. Journal of Gastroenterology and Hepatology.
Iacovou M. et al. (2015). The low FODMAP diet and its application in East and Southeast Asia. Journal of Neurogastroenterology and Motility.
Leiß O. (2014). Fiber, food intolerances, FODMAPs, gluten and functional bowel disorders — update 2014. Zeitschrift für Gastroenterologie.
Monash University — FODMAP composition tables and app (Department of Gastroenterology, Monash University, Melbourne). The dataset behind every serve size on the FODMAP axes: it is the group that measured them, and low-FODMAP thresholds are per-serve rather than per-food.
Hernández F. et al. (2016). Physico-chemical, nutritional, and volatile composition and sensory profile of Spanish jujube (Ziziphus jujuba Mill.) fruits — four sugars identified and quantified by HPLC, SORBITOL among them, plus citric, malic, ascorbic and succinic acids. Journal of the Science of Food and Agriculture 96(8), 2682–2691.
Rahman A.S. et al. (2015). Double-blind cluster randomised controlled trial of wheat flour chapatti fortified with micronutrients — 3030 µg retinol equivalent as RETINYL PALMITATE per kilogram of flour, about three micrograms per gram. Maternal & Child Nutrition 11(Suppl 4), 120–131.
Krause V.M. et al. (1998). Fortified foods contribute one half of recommended vitamin A intake in poor urban Guatemalan toddlers — fortified sugar measured at a median of 3.3 retinol equivalents per gram against a target of 13–17. Journal of Nutrition 128(5), 860–864.
Timm D.A. et al. (2010). Wheat dextrin, psyllium and inulin produce distinct fermentation patterns, gas volumes and short-chain fatty acid profiles in vitro — inulin produced significantly more hydrogen and total gas than wheat dextrin. Journal of Medicinal Food 13(4), 961–966.
Noack J. et al. (2013). Fermentation profiles of wheat dextrin, inulin and partially hydrolysed guar gum in an in vitro digestion and batch fermentation model — wheat dextrin produced the LEAST gas at 8, 12 and 24 hours. Nutrients 5(5), 1500–1510.
Ertugay N. & Hamamci H. (1997). Continuous cultivation of bakers' yeast — change in cell composition at different dilution rates, and the effect of heat stress on trehalose level: trehalose falls from 33 to 8.6 mg and glycogen from 150 to 93 mg per gram of biomass as the dilution rate rises. Folia Microbiologica (Praha) 42(5), 463–467.
USDA — National Nutrient Database (FoodData Central).

Histamine & tyramine (biogenic amines)

Histamine and tyramine rise with fermentation and storage, so we rely on studies that measured amines in specific foods.

Marcobal A. et al. (2005). Histamine content of red wines (ELISA/HPLC). Food Research International.
Piersanti A. et al. (2014). Histamine in fish products — four years of official-control results. Food Chemistry.
Şenöz B. et al. (2000). Biogenic amines in Turkish sausages (sucuk). Journal of Food Science.
Blackwell B. et al. (1969). Histamine and tyramine content of yeast products. Journal of Food Science.
Zuberbier T. et al. (2022). The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis and management of urticaria. Allergy 77, 734–766. The work every additive note on this axis actually leans on: it records that pseudoallergic, non-IgE reactions to naturally occurring food ingredients — and in some cases to additives — have been observed in some patients, and that the pseudoallergen-free and low-histamine diets built on that remain “controversial and as yet unproven in well-designed double-blinded placebo-controlled studies”.
Ntzimani A. et al. (2008). Biogenic amines in smoked turkey breast fillets by packaging condition. Food Microbiology.
Shalaby A. (2000). Biogenic amines in mature and germinating legume seeds, and during cooking. Nahrung.
Villanueva Valero B. et al. (2005). Biogenic amines, polyamines and total aerobic count during storage of vacuum-packaged kidney, liver and spleen. Food Science and Technology International.
Szczyrba A. et al. (2024). Histamine in cow's milk by storage condition. Medycyna Ogólna i Nauki o Zdrowiu.
Byun B. et al. (2013). Biogenic amines in doubanjiang and tofu. Food Science and Biotechnology.
De Borba B. et al. (2007). Biogenic amines in alcoholic beverages (ion chromatography). Journal of Chromatography A.
Ramos B. et al. (2009). Yolk biogenic amines during storage of shell hen eggs. Food Chemistry.
Bandeira C. et al. (2012). Bioactive amines in fresh, canned and dried sweet corn. Food Chemistry.
Borges C. et al. (2019). Bioactive amines during ripening and thermal processing of bananas and plantains. Food Chemistry.
Emer C.D. et al. (2021). Biogenic amines and starter cultures in malolactic fermentation. Australian Journal of Grape and Wine Research.
Behera B.C. Citric acid from Aspergillus niger: a comprehensive overview. Critical Reviews in Microbiology — for additives produced by fungal fermentation.
Shulman K.I. et al. (1989). Dietary restriction, tyramine, and the use of monoamine oxidase inhibitors — tyramine assayed in over 100 foods. Journal of Clinical Psychopharmacology.
Sen N.P. (1969). Analysis and significance of tyramine in foods. Journal of Food Science.
Comas-Basté O. et al. (2020). Histamine intolerance — the current state of the art. Biomolecules.
Sattler J. et al. (1985). Inhibition of human and canine diamine oxidase by drugs. Agents and Actions.
Mayer H. et al. (2010). Biogenic amines in cheese by ultra-pressure liquid chromatography. Journal of Chromatography A.
Linares D. et al. (2012). Factors influencing biogenic amine accumulation in dairy products. Frontiers in Microbiology.
Pekcici M. et al. (2021). Biogenic amine contents in Turkish dairy products. Journal of Food Measurement and Characterization.
Fox P.F. (2012). Cheese — Chemistry, Physics and Microbiology, Volume 1, second edition.
Suzzi G. et al. (2003). Biogenic amines in dry fermented sausages — a review. International Journal of Food Microbiology.
Latorre-Moratalla M. et al. (2017). Tyramine and histamine risk assessment for dry fermented sausages. Food and Chemical Toxicology.
Veciana-Nogués M. et al. (1989). Histamine and tyramine in preserved and semi-preserved fish products. Journal of Food Science.
Visciano P., Schirone M., Tofalo R. & Suzzi G. (2012). Biogenic amines in raw and processed seafood — storage temperature, handling, decarboxylase-carrying microbes and free amino acid availability as the governing factors. Frontiers in Microbiology 3, 188.
Jabłońska-Ryś E. et al. (2020). Biogenic amines in processed and unprocessed mushrooms. Journal of Food Composition and Analysis.
Křížek M. et al. (2011). Biogenic amines in fish stored at 3 °C and at 15 °C. Acta Veterinaria Brno.
Triki M. et al. (2018). Free amino acid and biogenic amine contents of fresh meat during chilled storage. Foods.
Ly D. et al. (2008). Serotonin, tryptamine and tyramine in food vegetables (HPLC). Journal of Medicinal Food.
Simon-Sarkadi L. et al. (1994). Biogenic amines in leafy vegetables. Zeitschrift für Lebensmittel-Untersuchung und -Forschung.
Świder O. et al. (2020). Biogenic amines and free amino acids in traditional fermented vegetables. Journal of Agricultural and Food Chemistry.
Toro-Funes N. et al. (2015). Biologically active amines in fermented and non-fermented commercial soybean products. Food Chemistry.
Gobbi L. et al. (2019). Biogenic amines determination in plant milks. Beverages.
Ordóñez J. et al. (2013). A survey of biogenic amines in vinegars. Food Chemistry.
Nalazek-Rudnicka K. et al. (2021). Biogenic amines in beers produced by different methods. Foods.
Restuccia D. et al. (2015). Biogenic amine profiles in conventional and organic cocoa-based products. Food Additives & Contaminants Part A.
Pastore P. et al. (2005). Biogenic amines in chocolate by ion chromatography. Journal of Chromatography A.
Brückner H. et al. (2012). Biogenic amines in infusions of tea (Camellia sinensis). Amino Acids.
Yilmaz C. et al. (2019). Serotonin in nuts and nut-containing products (LC-MS/MS). Food Chemistry.
Maintz L. & Novak N. (2007). Histamine and histamine intolerance. American Journal of Clinical Nutrition.
Sadighara P. et al. (2024). Tyramine, a biogenic agent in cheese: amount and factors affecting its formation — a systematic review. Food Production, Processing and Nutrition 6, article 30.
McCabe-Sellers B.J. et al. (2006). Tyramine in foods and monoamine oxidase inhibitor drugs — a crossnational comparison. Journal of Food Composition and Analysis.
Gardner D.M. et al. (1996). The making of a user-friendly MAOI diet. Journal of Clinical Psychiatry.
EFSA Panel on Biological Hazards (2011). Risk-based control of biogenic amine formation in fermented foods — no adverse effect at 50 mg histamine, or at 600 mg tyramine without MAOI treatment and 6 mg with a classical MAOI. EFSA Journal.
Geha R.S. et al. (2000). Multicenter, double-blind, placebo-controlled, multiple-challenge evaluation of reported reactions to monosodium glutamate. Journal of Allergy and Clinical Immunology 106(5), 973–980.
AOP and DOP specifications of the cheeses named — Parmigiano Reggiano, Grana Padano, Gorgonzola, Fontina, Roquefort, feta, Le Gruyère. The source for every minimum ageing quoted in a note, and for what each one permits: Grana Padano allows lysozyme up to 2.5 g per 100 kg where Parmigiano Reggiano allows no additive at all.
Champagne appellation rules — twelve months minimum on the lees and fifteen months in the cellar before release, three years for a vintage. The lees contact is the condition that produces amines.
SIGHI — Swiss Interest Group Histamine Intolerance, food-compatibility list (cross-check).
Regulation (EC) No 853/2004, Annex III — specific hygiene rules for products of animal origin: Section VIII requires operators to keep fishery products within the histamine limits, Section XIV defines gelatine.
Commission Regulation (EC) No 2073/2005 on microbiological criteria, as amended by Reg. (EU) No 1019/2013 — the histamine limits themselves: 100 mg/kg mean and 200 mg/kg maximum for species rich in free histidine, raised to 200 and 400 mg/kg for products matured in brine.

Salicylates

Salicylates concentrate in herbs, spices and some fruits — taken from dedicated content studies. The additive entries are different: most of those additives contain no salicylate at all, and they are listed because the pseudoallergen-free diet used in salicylate intolerance removes them.

Zhou X. et al. (2022). Composition of the quinochalcones hydroxysafflor yellow A and anhydrosafflor yellow B across 144 safflower cultivars — the yellow pigments of the water extract used as food colourants. Food Research International.
Swain A. et al. — Friendly Food (RPAH Elimination Diet, Royal Prince Alfred Hospital).
Swain A.R., Dutton S.P. & Truswell A.S. (1985). Salicylates in foods — salicylic acid in 333 food items by HPLC read at 235 nm, the most comprehensive set then published; vegetables from 0 to 6 mg per 100 g, the 6 being gherkins, and the authors' own note that their extraction was more complete than earlier methods and their values run higher. Journal of the American Dietetic Association 85(8), 950–960.
Malakar S., Gibson P.R., Barrett J.S. & Muir J.G. (2017). Naturally occurring dietary salicylates â a closer look at common Australian foods. 112 foods measured by GC-MS with a deuterated internal standard, reported per serve as well as per kilogram: 1.28â26.93 mg/kg in vegetables, 2.13â36.90 in fruits, 2.80â604.97 in herbs and spices. Journal of Food Composition and Analysis 57, 31â39.
Wood A. et al. (2011). A systematic review of salicylates in foods. Molecular Nutrition & Food Research.
Scotter M.J. et al. (2007). Free salicylic acid and acetyl salicylic acid content of foods using gas chromatography–mass spectrometry — detectable salicylate in only 37 of 76 foods, and “many inconsistencies with previous data”. Food Chemistry 105, 273–279. doi:10.1016/j.foodchem.2007.03.007
Paterson J.R. et al. (2006). Salicylic acid content of spices. Journal of Agricultural and Food Chemistry.
Gajewska D., Kęszycka P.K. & Szkop M. (2019). Dietary salicylates in herbs and spices — salicylate content of culinary herbs and spices by RP-HPLC with fluorescence detection, the highest concentrations in dried basil and cumin, then dried oregano and cloves. Food & Function 10(11), 7037–7041. doi:10.1039/c9fo01660k
Venema D. et al. (1996). Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection — no acetylsalicylic acid in any of 30 foods reputed high, and 0–1 mg/kg of salicylic acid in vegetables and fruits. Journal of Agricultural and Food Chemistry 44, 1762–1767. doi:10.1021/jf950458y
Janssen P.L. et al. (1996). Urinary salicylate excretion in subjects eating a variety of diets shows that amounts of bioavailable salicylates in foods are low. American Journal of Clinical Nutrition 64(5), 743-747.
Janssen P.L. et al. (1997). Acetylsalicylate and salicylates in foods. Cancer Letters 114(1-2), 163-164.
Duthie G. et al. (2011). Natural salicylates: foods, functions and disease prevention. Food & Function.
Baenkler H.-W. (2008). Salicylatintoleranz — Pathophysiologie, klinisches Spektrum, Diagnostik. Deutsches Ärzteblatt.
Dölle-Bierke S. et al. (2020). Dietary implications in acetylsalicylic acid intolerance — DGAKI position statement. Allergo Journal International.
Herrmann K. (1990). Salicylsäure und andere Hydroxybenzoesäuren in Lebensmitteln. Ernährungs-Umschau.
Herrmann K. (1989). Hydroxycinnamic and hydroxybenzoic acid compounds in foods. Critical Reviews in Food Science and Nutrition.
Ramírez-Anaya J. del P. et al. (2015). Phenols in Mediterranean vegetables by domestic cooking method. Food Chemistry.
U.S. FDA — colour additive status list: FD&C Red No. 2 (amaranth, E 123) delisted for food use in 1976 and not permitted since.

Oxalates

Oxalate content differs widely between plants — taken from food-content tables.

Noonan S.C. & Savage G.P. (1999). Oxalate content of foods and its effect on humans. Asia Pacific Journal of Clinical Nutrition.
Savage G.P. et al. (2002). Soluble and insoluble oxalate content of mushrooms — 58.9–104.1 mg/100 g of dry matter in raw cultivated mushrooms. International Journal of Food Sciences and Nutrition 53(4), 293–296.
Siener R. et al. (2006). Oxalate content of cereals and cereal products — whole grain wheat 53.3–76.6 mg/100 g of total oxalate, wheat bran 457.4, by HPLC-enzyme-reactor. Journal of Agricultural and Food Chemistry 54(8), 3008–3011.
Israr B. et al. (2013). Effects of phytate and minerals on the bioavailability of oxalate from food. Food Chemistry 141(3), 1690–1693.
Ghosh Das S. & Savage G.P. (2012). Total and soluble oxalate content of Indian spices. Plant Foods for Human Nutrition.
Schröder T., Vanhanen L. & Savage G. (2011). Oxalate content in commercially produced cocoa and dark chocolate. Journal of Food Composition and Analysis 24(7), 916–922.
Holmes R. et al. (2001). Contribution of dietary oxalate to urinary oxalate excretion. Kidney International.
Jaeger Ph. et al. (2004). Dietary intake and intestinal absorption of oxalate in calcium stone formation. Nephron Physiology.
Passman C.M. et al. (2009). Effect of soda consumption on urinary stone risk parameters — cola oxalate under 1 mg/L by ion chromatography, urinary oxalate unchanged against water. Journal of Endourology 23(3), 347–350.
Knight J. et al. (2010). Metabolism of fructose to oxalate and glycolate — controlled diets up to 21 % of calories from fructose change urinary oxalate not at all. Hormone and Metabolic Research 42(12), 868–873.
Rodgers A. (1999). Effect of cola consumption on urinary biochemical and physicochemical risk factors — urinary oxalate rises after a cola load in 45 volunteers. Urological Research 27(1), 77–81.
Ferraro P.M. et al. (2013). Soda and other beverages and the risk of kidney stones — sugared cola tracks with stones, diet cola does not. Clinical Journal of the American Society of Nephrology 8(8), 1389–1395.
Abdel-Moemin A. (2014). Oxalate content of Egyptian-grown fruits, vegetables and daily herbs. Journal of Food Research.
Chai W. & Liebman M. (2005). Effect of different cooking methods on vegetable oxalate content — boiling removes 30–87 % of soluble oxalate against 5–53 % for steaming, with the loss recovered in the cooking water. Journal of Agricultural and Food Chemistry 53(8), 3027–3030.
Quinteros A. et al. (2003). Effect of cooking on the oxalate content of pulses (enzymatic procedure). International Journal of Food Sciences and Nutrition.
Gad S. et al. (1982). Oxalate in leafy vegetables and dry legumes. Food Chemistry.
Ramasastri B. et al. (1983). Calcium, iron and oxalate content of condiments and spices. Qualitas Plantarum — Plant Foods for Human Nutrition.
Perera C. et al. (1990). Calcium oxalate crystals — the irritant factor in kiwifruit. Journal of Food Science.
Merusi C. et al. (2010). Determination of nitrates, nitrites and oxalates in food products by capillary electrophoresis with pH-dependent electroosmotic flow reversal — a method paper, applied to unnamed vegetable samples. Food Chemistry 120, 615–620. doi:10.1016/j.foodchem.2009.10.035
Storcksdieck genannt Bonsmann S. et al. (2008). Oxalic acid and non-haem iron absorption — kale versus spinach. European Journal of Clinical Nutrition.

Nickel

Nickel varies with soil and food type — from dietary nickel-content studies.

Hynstova V. et al. (2018). Pigments and heavy metals in dietary supplements containing Chlorella vulgaris and Spirulina platensis — nickel determined by graphite-furnace atomic absorption in 14 commercial products. Journal of Pharmaceutical and Biomedical Analysis 148, 108–118.
Flyvholm M.-A. et al. (1984). Nickel content of food and estimation of dietary intake. Z Lebensm Unters Forsch.
Smart G.A. & Sherlock J.C. (1987). Nickel in foods and the diet (canned foods, cereals, processing equipment). Food Additives & Contaminants.
Ruick G. (1988). Untersuchungen zum Nickelgehalt von Lebensmitteln (933 market samples). Die Nahrung.
Noël L. et al. (2012). Ni and other trace elements in foodstuffs — Second French Total Diet Study (ICP-MS). Food Chemistry.
Amaro M. et al. (1998). Nickel content in cow's, ewe's and goat's milk. Lait.
Jorhem L. et al. (2017). Metals in meat, charcuterie, dairy and beverages — four decades of analyses. Swedish Food Agency, report 28/2017.
Zeiner M. & Juranović Cindrić I. (2018). Harmful elements (incl. nickel) in wild berries and fruits — lingonberries, blueberries and rose hips from an unpolluted area of Croatia. Toxics 6(2), 31.
Guerra F. et al. (2012). Heavy metals in vegetables and potential risk for human health. Scientia Agricola.
Duran A. et al. (2008). Trace element levels in dried fruit samples. International Journal of Food Sciences and Nutrition.
Virgilio A. et al. (2015). Cd, Ni and V in spices (HR-CS GF-AAS). Journal of the Brazilian Chemical Society.
Ababneh F. et al. (2017). Trace elements in medicinal herbs and their water infusions. International Journal of Analytical Chemistry.
Cabrera-Vique C. et al. (2011). Nickel levels in convenience and fast foods. Science of the Total Environment.
Nie J.-Y. et al. (2016). Assessing the concentration and potential health risk of heavy metals in China's main deciduous fruits — Pb, Cd, Cr and Ni in apple, pear, peach, grape and jujube; nickel the highest of the four, and the five fruits together no more than 1.1 % of the tolerable daily intake. Journal of Integrative Agriculture 15(7), 1645–1655.
Bouga M. & Combet E. (2015). Seaweed and seaweed-containing foods in the UK — iodine, toxicity, nutrition. Foods.
Ahmed M. et al. (2024). Essential and non-essential metals in coconut milk. Journal of Food Composition and Analysis.
Plant-based milk alternatives: assessing the occurrence of chemical and microbiological contaminants in soy, oat, rice and almond beverages from the Italian market — 42 beverages screened for pesticides, mycotoxins, toxic trace elements and tropane alkaloids. Food Control (2024), PII S0956713524007229. NOT OPENED: the publisher returns HTTP 403 and the journal is not in PubMed.

Lactose

Lactose content comes straight from dairy composition tables.

USDA — National Nutrient Database (FoodData Central).
Ciqual — French food composition table (ANSES).
Frida Food Data v3 (2017) — National Food Institute, Technical University of Denmark.
McCance & Widdowson's Composition of Foods integrated dataset — Public Health England (2015).
Norwegian Food Composition Database (2015) — Norwegian Food Safety Authority.
Schweizer Nährwertdatenbank v6.3 (2021) — Bundesamt für Lebensmittelsicherheit und Veterinärwesen.
AUSNUT 2011–13 — Food Standards Australia New Zealand.
EFSA Panel on Dietetic Products, Nutrition and Allergies (2010). Scientific Opinion on lactose thresholds in lactose intolerance and galactosaemia — the vast majority of people with lactose maldigestion tolerate up to 12 g as a single dose, no single threshold can be set for everyone, and some react below 6 g. EFSA Journal 8(9), 1777.
Portnoi P.A. & MacDonald A. (2009). Determination of the lactose and galactose content of cheese for use in the galactosaemia diet — 109 samples of 12 cheese types; gruyère, emmental, jarlsberg, parmigiano reggiano, grana padano and mature cheddar had neither sugar detectable. Journal of Human Nutrition and Dietetics 22, 400–408.
EFSA Panel on Dietetic Products, Nutrition and Allergies (2010). Scientific Opinion on the substantiation of health claims related to live yoghurt cultures and improved lactose digestion — the claim EFSA accepted, on the ground that the cultures carry their own lactase into the gut. EFSA Journal 8(10), 1763.
Commission Regulation (EU) No 432/2012 — the list of permitted health claims, which includes the only approved lactose claim: live yoghurt cultures improving lactose digestion.

Gluten

Gluten is a yes/no: does the food contain a gluten grain (wheat, barley, rye)?

Regulation (EU) No 1169/2011, Annex II — cereals containing gluten (wheat incl. spelt and khorasan, rye, barley, oats, hybrids and products thereof) among the 14 allergens requiring mandatory declaration; Annex II also lists the exemptions, including wheat-based glucose syrups and maltodextrins.
Commission Implementing Regulation (EU) No 828/2014 — “gluten-free” at or below 20 mg/kg, “very low gluten” at or below 100 mg/kg.
Coeliac UK — gluten-free diet guidance: distillation removes any trace of gluten from all spirits; beer, lagers, stouts and ales not suitable; a beer may be labelled gluten free only at or below 20 ppm; barley malt vinegar to be both tested and labelled.
AFDIAG (France) — les trois céréales interdites, blé (toutes espèces de Triticum), orge et seigle, leurs hybrides comme le triticale, et l'avoine non contaminée « consommable par presque tous les cœliaques ».
Biesiekierski J. et al. (2013). Gluten and fermentable carbohydrates in non-coeliac gluten sensitivity. Gastroenterology.
Brouns F. et al. (2013). Does wheat make us fat and sick? Journal of Cereal Science.
Schnedl W. et al. (2018). Non-coeliac gluten sensitivity — is it due to histamine intolerance? Inflammation Research.

Food additives

Additive flags are not intolerance levels. They come from studies of specific additives — emulsifiers and sweeteners on the gut microbiota, colours on children's behaviour — and from regulatory opinions where an additive has been restricted or withdrawn.

Chassaing B. et al. (2015). Dietary emulsifiers impact the mouse gut microbiota. Nature.
Chassaing B. et al. (2022). Carboxymethylcellulose alters the human gut microbiome. Gastroenterology.
Suez J. et al. (2022). Personalized microbiome-driven effects of non-nutritive sweeteners. Cell.
McCann D. et al. (2007). Food additives and hyperactive behaviour in children — the Southampton study. The Lancet.
Silva M. et al. (2022). Food colour additives — chemistry, applications and health side effects. Foods.
EFSA (2021). Safety assessment of titanium dioxide (E171) as a food additive. EFSA Journal.
Sweis I. et al. (2018). Manufactured citric acid and inflammatory reactions — a series of four case reports. Toxicology Reports.
Frisvad J. et al. (2011). Fumonisin and ochratoxin production in industrial Aspergillus niger strains. PLoS One.
Perrone G. et al. (2017). Aspergillus species and their associated mycotoxins. Methods in Molecular Biology.
Mudgil D. et al. (2014). Guar gum — processing, properties and food applications. Journal of Food Science and Technology.
EFSA Panel on Food Additives (2017). Re-evaluation of glutamic acid (E 620) and the glutamates (E 621–E 625) as food additives — ADI 30 mg/kg bw per day, and exposure exceeding both it and doses associated with adverse effects in humans for some population groups. EFSA Journal 15(7), 4910.
EFSA Panel on Food Additives (2012). Re-evaluation of butylated hydroxytoluene BHT (E 321) as a food additive — ADI raised to 0.25 mg/kg bw per day, exceeded at the 95th percentile by children in Finland and the Netherlands. EFSA Journal 10(3), 2588.
EFSA — the re-evaluation PROGRAMME for authorised food additives under Regulation (EU) No 257/2010 (2009–2020). NOT A DOCUMENT: several hundred separate opinions across eleven years, which is why it cannot be opened as one. The opinions actually relied on are listed individually here as each is read.
EFSA (2016). Re-evaluation of sulfur dioxide (E 220) and the sulfites (E 221–E 228) as food additives — group ADI 0.7 mg SO₂ equivalent/kg bw per day, kept but made temporary, with estimated exposure above it for all population groups. EFSA Journal 14(4):4438.
Regulation (EU) No 231/2012 — purity criteria for food additives.
Commission Regulation (EU) No 1129/2011 — replaces Annex II to the food additives regulation with the Union list of permitted additives; applicable from 1 June 2013.
Regulation (EC) No 1333/2008 on food additives — the authorised list, the conditions of use, and Annex V, which requires the six colours of the Southampton study to carry the warning “may have an adverse effect on activity and attention in children”.
Regulation (EC) No 1334/2008 on flavourings — why “flavouring” on a label need not name what it is made of.