Comprehensive study of honey with protected denomination of origin and contribution to the enhancement of legal specifications

Abstract

In this study the characterization of a total of 60 honey samples with Protected Denomination of Origin (PDO) collected over three harvests (2009-2011, inclusive), from the Northeast of Portugal was carried out based on the presence of pollen, physicochemical and microbiological characteristics. All samples were found to meet the European Legislation, but some didn't meet the requirements of the PDO specifications. Concerning the floral origin of honey, our results showed the prevalence of rosemary (Lavandula pedunculata) pollen. The microbiological quality of all the analyzed samples was satisfactory, since fecal coliforms, sulfite-reducing clostridia and Salmonella were absent, and molds and yeasts were detected in low counts. Significant differences between the results were studied using one-way analysis of variance (ANOVA), followed by Tukey's HSD test. The samples were submitted to discriminant function analysis, in order to determine which variables differentiate between two or more naturally occurring groups (Forward Stepwise Analysis). The variables selected were in this order: diastase activity, pH, reducing sugars, free acidity and HMF. The pollen spectrum has perfect discriminatory power. This is the first study in which a honey with PDO was tested, in order to assess its compliance with the PDO book of specifications.

Figure 1

Polinic spectrum of the “Terra Quente” honeys from the three harvests. The letters (a,b,c) represents which honeys are different by Tukey test with significance of α = 0.05.

Figure 2

Colour of the samples in each harvest.

Figure 3

Separation of harvest honeys using palynological analysis: plot of discriminant scores.

Figure 4

Separation of harvest honeys using physicochemical analysis: plot of discriminant scores.

Figure 5

“Terra Quente” region, in which the DOP honey samples were collected.