Ketchup

Ketchup concentrates tomato and then adds vinegar, and the vinegar is a second source of histamine rather than a preservative that helps: it is itself a double ferment. The bottle then lives in a fridge door for months, which is the third factor.

Ketchup concentrates tomato and then adds sugar - often high-fructose corn syrup, sometimes onion powder. A tablespoon is the usual limit, and it is the added ingredients rather than the tomato that decide where a given brand sits.

Ketchup is concentrated tomato plus added sugar, and in many markets that sugar is high-fructose corn syrup. A tablespoon is a real dose because the concentration is high, not because the portion is.

Ketchup carries added sugar to balance the tomato's acidity, and a good deal of it - roughly a quarter by weight in many recipes. A tablespoon is a real dose.

Ketchup is concentrated tomato plus vinegar and spices, and all three carry salicylate. It is used in repeated small squeezes rather than one serving, which is what makes the daily total climb.

Ketchup is tomato, sugar, vinegar and spice, and the vinegar is the thing to check: malt vinegar is made from barley, and it is used in some British and northern European recipes where spirit vinegar would be used elsewhere. The major brands use spirit vinegar.

Ketchup's FODMAP level is sugar - concentrated tomato plus what was added. The chains would come from onion powder if a given brand uses it, which is why the ingredient list decides this one rather than the category. This is a PREPARED food, and that is the difficulty on this axis: the oligosaccharides come from whatever went in - onion, garlic, a legume, an added fibre - not from a single plant that could be looked up. The level follows work on fructooligosaccharides in prepared and preserved foods for that reason. The survey behind this ranks by PLANT FAMILY rather than by food: the Compositae highest in total fructooligosaccharide, then the Allium species. A prepared food takes its place from whichever of those went into it - onion and garlic are Allium, artichoke and chicory are Compositae - and the survey names no prepared food itself.

Ketchup is cooked tomato with sugar and vinegar, and tomato is low. Tyramine needs three things - protein, bacteria and time - and a cooked or dried product has had the second removed and the third stopped.

Ketchup is concentrated tomato, and tomato takes up more than most fruit. It is also acidic and stored for months, which is the classic setup for a container to contribute a little.

Ketchup concentrates tomato, and the tomato's oxalate concentrates with it. Ketchup arrives in small repeated squeezes rather than one serving, so the concentration is real and the dose at any one time is not.