Free amino acid determination by GC-MS combined with a chemometric approach for geographical classification of bracatinga honeydew honey (Mimosa scabrella Bentham)

Honeydew honey is increasingly being valued by consumers and the food industry worldwide, particularly bracatinga honeydew honey (Bhh) obtained from honeydew of plant-sucking insects (Tachardiella sp.) that infest the tree species bracatinga (Mimosa scabrella Bentham) from Santa Catarina State (SC), Brazil. Due to mixture between honeys, authentication is an important aspect of quality control and its regard with the origin guarantee in terms of source and geographical documentation needs to be determined. We therefore determined the free amino acids (FAA) by GC-MS to elucidate the contribution of plant-sucking insects (Tachardiella sp.) and Apis mellifera bees to the Bhh in order to classify this honey from five different geographic areas of Santa Catarina, using chemometric approach. The results showed that proline is provided exclusively by Apis mellifera bees, and this honey could be differentiated into geographic regions based on the FAA profile. Principal component analysis identified the main FAA responsible for clustering of the samples in these regions (the sum of the first 2 principal components account for 82% of the total variance) and provided a similar discrimination of the geographical location map, particularly with regard to the northern and southern geographical orientations. This method is therefore a reliable analytical strategy for the authentication of this honey.