Authenticity of Greek honey based on phenolic compounds and physicochemical characteristics

The main technique for classifying honey according to its botanical origin is melissopalynology, using pollen analysis. However, there is an issue where beekeepers collect pollen at the entrance to the hive or pollen is added to the honey after it is harvested with the aim of deceiving consumers. In the current work, the potential to authenticate Greek honeys based on their phenolic profile and some of their physicochemical characteristics, such as electrical conductivity, HMF content, and diastase activity, since they are the main quality parameters of honey, was studied. Initially, 95 honey samples from 11 botanical sources were collected from different places in Greece. Pollen analysis was performed to classify the honeys into individual species, and then HMF content, diastase activity, electrical conductivity values, total phenolic content, and 23 individual phenolic compounds were determined. An authenticity study was carried out using ANOVA and MANOVA, and PCA, LDA, OPLS-DA as well as logistic regression. It was found that the phenolic compound chlorogenic acid can be used as a marker for Greek chestnut honey, homogentisic acid and 2-cis,4-trans-abscisic acid can be used as markers for Greek Arbutus honey and the combination of gallic acid and protocatechuic acid can be used as markers for Greek oak honeydew honey, and are proposed as alternative or complementary ways of ensuring the authenticity of Greek honey.