Free Amino Acids Content of Honeys from Poland

The objective of this study was to investigate free amino acids composition of Polish honeys with different botanical origin. Honeys (n=18) with dominant buckwheat, raspberry, acacia, heather and goldenrod pollen, and honeydew honey were analysed. For determination of free amino acids liquid chromatography methods were applied. Identification of 25 free amino acids was performed. Considerable variation in the total content of free amino acids ranging from 186.19 mg/kg to 921.08 mg/kg was stated. The dominant free amino acid in all types of honey was proline with the highest detected amount in one sample of heather honey 387.88 mg/kg. As an indicator of honeys with predominant raspberry and buckwheat pollen high concentrations of aspartic acid and asparagine (accounting for ca. 20 and more mg/kg) are suggested. The content of tyrosine, leucine, isoleucine and valine ranging from 10 to ca. 20 mg/kg was characteristic of raspberry and at concentrations above 20 mg/kg of buckwheat honeys. The cluster analysis showed the closest correlation between heather and goldenrod honeys. The largest distance was stated between buckwheat and all other honey groups. The results show that it was impossible to clearly distinguish the botanical origins of Polish honey samples based on their amino acid composition.