A comprehensive characterization of phenolics, amino acids and other minor bioactives of selected honeys and identification of botanical origin markers

Abstract

Phenolic and amino acid profiles along with organic acid, vitamin and mineral contents, major and minor sugars and enzyme activities of selected honey samples collected in North America were analyzed using different methods and potential markers of their botanical origin were identified. Among the 29 detected phenolic compounds, and some were found to be a good chemical markers to distinguish a genuine honey given its propolis origin. Quantitative data and principal component analysis showed that hesperidin, caffeic acid/isoferulic acid, and p-hydroxybenzoic acid/p-coumaric acid have the most positive relationship to the orange, alfalfa, and buckwheat honey, respectively, indicating their potential roles as chemical markers of these floral honeys. Free amino acid profiles were similar in all other honeys except buckwheat which not only had significantly higher branched-chain amino acids but was the only floral honey that contained L-norvaline that was identified for the first time. The enzyme activities and the major and rare sugar composition helped explain the presence of the various organic acids in the honeys. Compositional data of these bioactives and other nutrients will not only serve as database information for honey derived from North America but also provide insightful knowledge for the underlining potential health benefits.