Study On The Difference Of Proteins In Various Honeys

This study was conducted with six samples of honeys of litchi, longan, acacia, loquat, linden and rape to find a new method to detect adulteration. The six proteins of honey was extracted, and a comparative analysis was conducted to find out the differences of them by SDS-PAGE gel electrophoresis and two-dimensional electrophoresis. By detection and analysis of honey proteins, from which to find the profile of proteins, we can determine if the honey was adulterated. The results of six honey proteins were shown below:(1) These six honeys were low in proteins, and the protein contents were different. The protein contents in honeys of litchi, longan, acacia, loquat, linden and rape were0.280mg/ml、0.208mg/ml、0.272mg/ml、0.176mg/ml、0.224mg/ml、0.192mg/ml, respectively.(2) The protein contents of raw honey were almost the same as processed honey in this study, which showed there is little effect on protein during honey processing.(3) When the honey proteins quantified, the same quality of proteins were analyzed by SDS-PAGE gel electrophoresis, from the profiles of proteins, six honey proteins were concentrated in55kD, but the contents of proteins were different between each of them. Most of the protein bands appeared between20kD-110kD. The proteins of six honey bears similarities among them, but the six honey also have their own specific proteins.(4) The proteins were extracted from six honey of the equal volume, then water added to the same volume, which were studied by SDS-PAGE gel electrophoresis according to the same volume of10μL. Proteins in the six honeys has four common bands which were55kD、35kD、30kD and25kD, but the contents of them were different. A collection of protein contents can been drawn, the lowest was from loquat honey, the protein contents from litchi honey and longan honey were higher than that from the others. The color of linden honey was darker than other samples in band116kD, which showed the same honey protein with different contents. There was a specific band in65kD in litchi honey,and the specific band of longan honey was in120kD. To acacia honey, the specific bands were in85kD、50kD and22kD, and the specific protein of rape honey was23.5kD. We can reach a conclusion that there were significant differences among these honey proteins by detecting the protein contents and specific proteins. (56) The proteins from six honeys were extracted for quantitative, the same quality of proteins were analyzed by SDS-PAGE gel electrophoresis. We can find that the isoelectric point of honey proteins were focused on pH4-7by two-dimensional electrophoresis. Six profiles had the similar patterns, and each honey had the specific protein spots in the corresponding region. The most abundant protein spots concentrated in pH6-9and the molecular weight was25-100kD. Four major regional were analyzed, the protein volume have significant differences at the regional in the molecular weight of25kD and pH6,6.3,6.7,7.2,7.5. The protein volume has significant differences at the regional in the molecular weight of85kD and pH6.5-7.3. The protein volume has significant differences at the regional in the molecular weight of55kD and pH6-8.5. The protein volume has significant differences at the regional in the molecular weight of41kD and pH6-7.3. Therefore the protein spots of six honeys have significant differences.(6) The proteins from6kinds of honeys were different, which could be employed to identify adulteration of mixed honeys.No proteins were isolated with the same extraction protocol, which evidence for discriminating honeys from high fructose syrup.