AN IMPROVED METHOD FOR POLLEN ANALYSIS OF HONEY

Filtration, rather than centrifugation, was investigated as a first st ep to extract pollen from honey. The filter with adhering pollen and s pores was then acetolyzed in a 1.5 ml microcentrifuge tube to speed up the remaining steps of sample preparation. Various filters were teste d and only those in polyester, cellulose, and cellulose acetate and po ly-acetate had no deleterious effect on pollen acetolysis. Among these , fast filtration of diluted 10 g honey samples was possible with poly ester and cellulose acetate filters, but polyester fibers trapped some pollen. Cellulose acetate membranes 47 mm in diameter with 0.8 mum po res (Sartorius SM111-04-47N) permitted the filtration of honey samples in less than 3 min and the filters dissolved totally during acetolysi s releasing the pollen. With these filters, a new method based on filt ration and followed by acetolysis in microcentrifuge tubes was develop ed and compared with standard pollen analysis starting with centrifuga tion at 1700 g (3000 rpm) for 10 min. Pollen recovery assays were cond ucted with a mountain honey and a test honey made of pollen-free honey to which pure pollen of Castanea, Helianthus, and Lilium was added. S ignificantly more pollen was recovered with the new method than with t he usual one with both honeys. Also, the pollen spectrum of the test h oney treated with the new method was similar to that of the pollen add ed originally, while it was significantly different when the test hone y was processed with the standard method. Thus the new method signific antly improved pollen extraction quantitatively and qualitatively, whi le decreasing sample preparation time by 50% and using less reagents a nd cheaper equipment.