Study On Protein And Amino Acids In Single Flower

Quality and nutritional value of honey are related with the floral origin. There are significant differences on commercial value of different monofloral honey, which results in the serious phenomenon of adulteration of honey. Thus the research of identification technology of floral origin should be launched at present. This paper began with major protein and amino acid in honey and investigated the content, SDS-PAGE pattern, fluorescence spectroscopy and amino acid composition of protein in honey, which provided the reference for the quality control of honey.(1) The results indicated that the protein contents of eight kinds of monofloral honey were in the range of 398.31±17.89～1839.10±11.19 mg/kg. There were significant differences on protein content of the same kind of honey. The protein content of jujube honey from shaanxi was the highest among all samples, at 1289.45±13.43 mg/kg, while that from shanxi was the lowest, at 598.76±10.41 mg/kg. The protein contents of monofloral honey from different floral origin were significant differences. The protein content of longan honey was the highest, at 1650.91 mg/kg(mean), whereas that of acacia honey was the lowest, at 543.65 mg/kg(mean).(2) Through an SDS-PAGE analysis of protein of different honey, the molecular weight of protein of all samples ranged from 14.4 kDa to 97 kDa. The protein bands of ～74 kDa and-58 kDa were found in all samples. Honey acquired from the same floral origin had the same number of protein bands and the molecular weight of protein bands was basically the same. The results showed that the composition of protein was not significant. But protein bands of monofloral honey from different floral origin were obviously different.～17 kDa protein existed only in jujube honey and also acts as the special protein of jujube honey for differentiating from other honey.(3) Fluorescence spectrum analysis of the protein in honey demonstated the maximum fluorescent absorption peaks of protein were at 324 nm,326 nm and 328 nm, which were part of absorption wavelength of tyrosine and tryptophan. The results showed that the maximum-fluorescent absorption peak of protein was not significant. But there were significant differences between the fluorescence intensity, and the fluorescence intensity of jujube honey was higher than that of other honey.(4) This paper investigated the composition of free amino acid and amino acid of protein in honey by HPLC-DAD. The experimental results showed that free amino acids were very rich in the honey, and the total content ranged from 5.283 to 17.634 mg/g. The content of proline was the highest, accounting for 41.62～67.91% of the total free amino acid. The types of free amino acid and amino acid of protein were not significant, but the contents were significant differences because of different floral origins.