Project description:Bees make honey from the nectar that they collect from flowers. The characteristics of honey are closely associated to original botanical species. Compare with sugars in honey, proteins are minor components but usually used as an important honey quality evaluation parameters. Flower-origin proteins could be a good marker for the authentication. However, as a minute component in honey proteome, plant origin proteins are hard to be detected in honey by regular proteomic approaches, such as gel-based techniques. In this study, Eriobotrya japonica Lindl. (loquat) nectar and its derivative monofloral honey were systematically compared, especially regarding the proteomes and enzymatic activities. Using two-dimensional electrophoresis and mass spectrometry, only bee-originated proteins were detected in loquat honey which were major royal jelly proteins and two uncharacterized proteins. Xylosidase, thaumatin, and two kinds of chitinases were detected in loquat floral nectar by the gel-based proteomic approach. To our knowledge, it is the first study to analysis nectar-originated enzymes’ activity in honey and we proposed that the zymography of chitinase is a potential marker for honey botanical origin authentication.
Project description:Honey is a widely consumed natural agricultural product due to its unique flavour, taste and its nutritional content. Honey bees form honey by collecting nectar from different flowers and then metabolising it to form honey which is stored in the hive. Currently attention is always focussed on the material composition of monofloral honeys from different plant sources. There is a lack of understanding of the differences in the transformation and composition of metabolites between plant nectar and the honey that is processed by bees after nectar feeding. In this study, loquat nectar and mature loquat honey were used for the detection of metabolites in both by Ultra Performance Liquid Chromatography-Tandem mass spectrometry (UPLC-MS/MS). The results showed that there was a significant difference in the relative content of non-volatile metabolites between the two. We detected a total of 914 non-volatile metabolites, of which 834 were detected in loquat nectar and 759 in loquat honey.