Research On The Change Of Protein And Carbohydrate Of Rape Honey In Ripening Process

Honey is a natural sweet substance made by sufficient ripening after combination of nectar or honeydew collected from different plants by honeybees with their own secretions.lt is composed of major compounds including carbohydrate,protein and enzyme.The composition and content of these components are associated with the kind of flower sources and the ripening process of honey.Honey is roughly divided into three types according to the different production mode,which are natural raw honey,concentrated honey and natural ripe honey.The ripening of honey is influenced by the factors,such as the florescence of nectar plant,bee forces and weather,leading to the production of natural ripe honey been restricted in a great degree.At present, there are several problems in the quality of the honey products,the primary problem is the production of immature honey.The active ingredients will be heavily damaged in the thermal processing owing to the high water content of honey.However,the natural ripe honey has a high nutritional value and significant health benefits because of the full ripening by bees.In order to evaluate the honey quality,abundance of study was taken,which simply analyzed the difference of components in different varieties of honey without consideration of the ripening process of honey.This study focus on the change of the protein and carbohydrate in the ripening process of honey for purpose of encouraging the production of natural ripe honey and improve the honey quality detection.The results as follows:(1)We determined the physicochemical parameters and the activity of four major enzymes of natural rape honey in ripening process and found that there was a good correlation between water content and soluble solids content and electrical conductivity indicating that the real water content in honey can be reflected by the solid content or electrical conductivity.In addition,a good correlation among amylase,a-glucosidase (Invertase) and P-glucosidase activity was found,so we can predict or evaluate several other enzymes activity in honey by detecting one of these enzymes activity.(2)We found the proteins of natural rape honey in the ripening process were always stable by SDS-PAGE and MALDI-TOF-MS technology. The results indicated that there were five major proteins from honeybees in natural rape honey,which were glucose oxidase, a-glucosidase,MRJP1,MRJP2and MRJP3respectively.The amounts of protein in natural rape honey dramaticlly increased from0.5303 mg/g to0.9163mg/g with the increase of ripening days simultaneou-sly(p<0.05),demonstrating that the ripening degree of honey can be characterized by the protein content.(3)Fructose and glucose are the major monosaccharides in honey through studying the variation of the carbohydrate in the ripening process by HPLC-ELSD.We analyzed the change of carbohydrate and enzyme activity and found that the continue rise of fructose content in the ripening process was caused by the hydrolysis of α-glucosidase. Besides,the D-trehalose and isomaltulose are constantly synthesised in the latter period of ripening process.