Analysis of Czech meads: Sugar content, organic acids content and selected phenolic compounds content

In this study, 22 samples of various Czech meads were analysed. Glucose and fructose content were determined by chromatographic method with evaporative light scattering detection; for the separation an amino column with an isocratically delivered mobile phase water:acetonitrile (90:10, v/v) was used. The content of hydroxymethylfurfural and organic acids (e.g. citric acid or malic acid) was determined by HPLC with UV detection in reversed phase mode, in both cases with an isocratic elution of mobile phase. Selected phenolic compounds (e.g. gallic acid or vanillin) were analysed using HPLC system equipped with electrochemical coulometric-array detector. A C18 column was used in the separation of phenolics with a mobile phase of 5 mM ammonium acetate in water (acidified with formic acid) and acetonitrile. All developed methods allowed to identify and quantify a total of 24 bioactive compounds in meads. A large variability of results was observed; e.g. glucose and fructose contents were in the ranges 68-237 g/L and 62-243 g/L, respectively; the content of hydroxymethylfurfural ranged from 27 mg/L to 209 mg/L; the most represented organic acid was gluconic acid with an average content 29.07 g/L; and finally, the amounts of phenolic compounds greatly differ depending on the type of admixture. (C) 2014 Elsevier Inc. All rights reserved.