PHYSICO-CHEMICAL PROPERTIES AND BIOACTIVE COMPOUNDS IN SLOVAK HONEYS

Abstract

Honey quality and authenticity are key factors affecting consumer trust and market value. However, differences between honey from small-scale apiaries and commercial production remain insufficiently characterised. This study evaluated selected physico-chemical parameters of Slovak honey samples to assess their quality and authenticity. Twenty-five apiary samples and six commercial samples (from retail and chain stores) were analysed. Basic analyses included water content (by refractometry), free acidity (FA) and pH (by potentiometric titration), electrical conductivity (EC, by conductometry), and hydroxymethylfurfural content (HMF, by HPLC). Special analyses focused on protein determination, particularly royal jelly proteins (RJPs) and apalbumin 1 (APA1, the major royal jelly protein), as well as antioxidant activity (AA, by DPPH• method) and total phenolic content (TPC, by spectrophotometry). Apiary samples were evaluated based on botanical and geographical origin. Brassica napus and Robinia pseudoacacia honeys exhibited significantly lower pH, EC, AA, TPC, and RJPs, which appears to be a natural characteristic of these honey types. These honeys originated from apiaries mainly in lowland areas (altitudes up to 300 m). When comparing apiary and commercial samples, apiary honeys contained lower HMF levels. Significant differences were also observed in protein content, particularly RJPs, which were higher in apiary samples. This suggests that apiary honey may contain a broader spectrum of biologically active substances. A more detailed characterization of Slovak honey in terms of sensory, physico-chemical, and biological properties could enhance its potential applications as a functional food in the future.