Characterization Of Protein And Amylase Profile For The Evaluation Of The Quality Of Three Honeys In Fujian Province

Honey is an important healthy food, and honey quality can be evaluated with properties ofthe honey protein and amylase. Fujian Province is one of the main honey producing areas inChina，and longan, Sweet Olive, Ivy Tree Bark are three key floral resource in this area. In orderto develop an accurate and effective method for controlling honey quality, this investigationevaluated honey quality according to the properties of protein and amylase in honey. Usinghoney samples originated from above three plants as experimental materials, we determined theprotein concentration, protein molecular weight, enzymatic activity of amylase, as well as theheat stability of amylase. The results showed that that the protein concentration of honey couldbe determined by Coomassie brilliant blue staining. The protein concentration of the pure honeysamples of longan, Sweet Olive and Ivy Tree Bark were159.13±0.82μg/mL,183.87±3.31μg/mL and82.14±1.61μg/mL，respectively. It was found that the protein concentrationdecreased when fructose corn syrup(amylase-free or containing amylase(20ml/(g.h)) was addedto the honey samples, and there was high correlation between protein concentration and theproportions of pure honey in the syrup-adulterated samples. SDS-PAGE analysis of honeyprotein revealed that in the range of molecular weight34-130kDa, a unique~50kDa proteinband was displayed in the protein profile of these three different pure honey samples. It wasshown that SDS-PAGE analysis could discriminate honey samples containing fructose cornsyrup that containing amylase, but could not detect adulteration of with starch inverted sugar inhoney. Finally, we determined the enzymatic activity of amylase of the honey samples bynational standard methods. The enzymatic activity of pure honey from longan, Sweet Olive andIvy Tree Bark was15.8mL(g.h),10.1mL/(g.h) and6.7mL/(g.h), respectively; and the amylasein pure honey could be inactivated after being treated under90℃for1h. The activity of amylasedecreased with amount of adulterated fructose corn syrup, and the decreasing rate wassignificantly correlated with the percentages of adulteration. However, adding fructose cornsyrup with amylase(20ml/(g.h) to honey samples could enhance the activity of amylase. Becausethe industrial amylases were heat-table and could remain their enzymatic activity even whentreated under100℃for1h, the amylase activity of heat treatment syrup-adulterated samples wasequal to the added commercial amylase. We further applied the established adulteration-detectingmethods to checked the quality of16commercial honey samples. The results showed: all honeysamples were lower in protein concentration; there were15samples did not display the characterprotein band in SDS-PAGE profile; all samples exhibited lower amylase activity than that of pure honey, and the No12remained its amylase activity after heated under100℃for1h. Theseresults indicated that the honey quality could be evaluated accurately through determining theprotein concentration, protein weight, amylase activity, and heat-stability of amylase. This studyprovide a reliable new approach for discriminating honey adulteration.