Identification of a novel N-caprylhistamine-β-glucoside from tomato fruits and LC-MS/MS-based food screening for imidazole alkaloids

•qualitative screening of cherry tomatoes for novel imidazole alkaloids.•synthesis of N-caprylhistamine and identification of a novel N-caprylhistamine-β-glucoside.•extension of an LC-MS/MS method for imidazole alkaloids in several food matrices.•large-scale screening of food items for the occurrence of six imidazole alkaloids.•sole detection of these alkaloids in tomato products with up to almost 5 mg/kg.