No abstract

The physical chemistry characteristics of honey are directly related to floral origin and, as a result, to the production region. There are some available methods that can determine the botanical or geographical origin of honey such as the free amino acids profile analysis. This paper reports data on the free amino acid composition, determined by reversed-phase high-performance liquid chromatography UV detection on 56 honey samples from three different Argentine regions, with characteristic apiarian flora. To evaluate if the quantified amino acid could be used to verify the geographical or botanical origin of honey, statistical analyses were performed. The cluster analysis showed that samples were grouped in clusters related to sampling regions and more strictly to apiarian flora around apiaries. Each cluster appears associated, in accordance with the principal component analysis, to high or low concentrations of different amino acids.

Time-course changes were studied on both concentration and spectral curve shape of 5-(hydroxymethyl)furfural (HMF) in solution. A significant and progressive absorbance drop at 284 nm was observed as well as the concomitant appearance of a new band at 252 nm with standard HMF solutions and glucose, saccharose, maltose, and lactose solutions. These changes depended mainly upon HMF starting concentration and were affected by both the storage temperature and the time between the preparation of the solution and the spectrophotometric measurement. There were less significant changes in honey, high-fructose corn syrup, and fructose solutions. The results indicate that fructose has a protective effect on HMF decomposition in solution. The spectrophotometric measurement should be made within 6 h after sample preparation, and the solutions should be kept at 4−8 °C to avoid HMF decomposition. Honey solutions with high HMF starting concentration showed significantly lower concentrations when they were clarified by ultrafiltration, compared with the usual clarification with Carrez reagent. This last fact could be attributed to a deficient sample deproteinization, which is improved either by ultrafiltration or by using a larger amount of Carrez reagent. Keywords: Hydroxymethylfurfural; honey; syrup; fructose; glucose; sugars; food

With the objective of evaluating the utility of the amino acid profile in the characterization of honey samples, 39 honey samples of two different harvests from a particular production zone in Córdoba, Argentina, were analyzed. Multivariate statistical techniques, such as principal component analysis (PCA), cluster analysis (CA), and multiple correspondence analysis (MCA), were applied to verify the correlation among the amino acid profiles, pollen percentages, and different harvests. PCA, CA, and MCA demonstrate the presence of differences of amino acid profiles between samples of the two harvests, such differences being mainly due to differences in pollen availability. Variation of the flora surrounding the apiary due to agricultural practices makes the analysis of amino acid profile typical for those cases with stabilized flora.