Plum butter

Plum butter is made by cooking down whole plums into a thick spread, which concentrates the fruit's natural compounds.

• Plums as liberators — plums are considered moderate histamine liberators, meaning they may prompt your body to release stored histamine even though their direct histamine content isn't especially high

• Concentration effect — a tablespoon of plum butter represents a much larger quantity of plum than you'd eat fresh, so the liberating effect may be more noticeable than eating the whole fruit

Compared to citrus marmalades or strawberry jams, plum butter is a middle-ground option — fine for many people in small amounts.