Characterization of the Proteins in Honey

This study focused on the extraction and identification of honey proteins from selected samples (Acacia, Tualang, and Gelam) from Malaysia. The extraction methods, dialysis, ammonium sulfate, and sodium tungstate precipitation methods, were used to obtain the proteins from the honey. The method of membrane dialysis provided the highest yield of proteins based on the Bradford assay. This method also provided the highest number of protein bands and the clearest protein bands on a 12% polyacrylamide gel compared with the other two precipitation methods. The results revealed that the precipitation methods may degrade the proteins because of the use of strong chemicals and losses after repeated transfers. Mass spectrometric data showed that the honey contained major royal jelly proteins (MRJP) such as MRJP-1, MRJP-2, MRJP-5, and MRJP-7, as well as a few uncharacterized proteins from Apis mellifera. MRJP-1 was the most abundant protein, particularly in Acacia samples. Honey proteins were also shown to possess significant antioxidant activity as free radical scavengers and reducing agents.