Grocery Store Checks ID For Fruit?

37 year-old Kate Lancaster was at a self-checkout at a Tesco grocery store in Plymouth, England, when she scanned a fruit salad made of melons and grapes, the self-check out machine alerted staff at the store that they needed to see her ID, because the machine needed to verify that she was over 18, the legal drinking age in the UK. Is Tesco worried fermented fruit might become alcoholic?