From Douglas Bolton
Your article on “waving goodbye” to discoloured fruit (Technology, 21 January) reminds me that my mother, among others I know of, had a homely way of preventing the discolouring of freshly sliced or grated pome: it was to sprinkle the newly cut fruit with lemon juice.
Our fruit salads usually included cut-up orange pieces as well, but the lemon juice still seemed to be needed to prevent the staining; so presumably the effective ingredient is in lemon juice, but not apparently in orange juice. It may be that lime or grapefruit would serve as well, but I have not experimented with either; the lemon juice remedy certainly does work.
