The isoflavone content of commercially-available feline diets in New Zealand

Abstract

To identify and quantify concentrations of the isoflavones genistein, daidzein, biochanin A and formononetin in commercially-prepared feline diets sold in New Zealand. METHODS: Feline diets (n=138) were collected from supermarkets, pet stores and veterinary clinics in New Zealand. Diets were classified into five categories based on the following criteria: the presence/absence of soy, the presence/absence of non-soy plant material, and dry matter (DM) content. A high performance liquid chromatography (HPLC)-based assay was developed and validated to identify and quantify concentrations of the isoflavones genistein, daidzein, biochanin A and formononetin. RESULTS: Isoflavones were detected in all categories of diet, and at quantifiable concentrations in 104/138 (75%) of the diets tested. More dry diets (127/138; 92%) contained isoflavones at quantifiable concentrations than moist diets (83/138; 60%,