DETERMINAÇÃO DE MARCADORES EM MÉIS DE ABELHAS-SEM-FERRÃO POR RMN: UM ESTUDO BASE PARA INVESTIGAÇÃO DE ADULTERAÇÕES

Abstract

The potential use of stingless bee honey by the food, cosmetics, and pharmaceutical industries has been increasing in recent decades. However, honeys from many species are poorly researched or have not been studied at all. Stingless bee honey has long been considered a food with high nutritional value and important therapeutic properties. Recently, the bioactive component trehalulose, a disaccharide isomer of sucrose with an α-(1→1) glucose-fructose glycosidic bond, was determined. Recent studies have highlighted the difficulty in distinguishing the presence of maltose and trehalulose in Brazilian stingless bee honeys using high-performance liquid chromatography (HPLC), and other studies have confirmed the presence of trehalulose in stingless bee honeys produced by a wide variety of species from different regions. Given that honey is a complex mixture, the opportunity arises to use Nuclear Magnetic Resonance (NMR) to determine possible markers of quality and authenticity. In this study, NMR spectroscopy was used to structurally elucidate maltose and trehalulose standards, along with standard spiking for unequivocal characterization of trehalulose in honeys from the species Tetragona clavipes and Melipona marginata. The results confirm the presence of trehalulose and indicate a considerably higher concentration of trehalulose relative to maltose in the honey from the species Tetragona clavipes, with a relative ratio of tautomers 1a, 1b, and maltose of 20:5:1, and in the honey from the species Melipona marginata, a relative ratio of 2:0.5:1. It is concluded that NMR spectroscopy is an effective technique for distinguishing sugars and their relative proportions, making it possible to confirm that the Tetragona clavipes honey sample has a considerably higher proportion of trehalulose than the Melipona marginata honey sample.