Among the enzymes already extracted from fungi are invertases (yeasts, moulds, &c.), which split cane-sugar and other complex sugars with hydrolysis into simpler sugars such as dextrose and levulose; diastases, which convert starches into sugars (Aspergillus, &c.); cytases, which dissolve cellulose similarly (Botrytis, &c.); peptases, using the term as a general one for all enzymes which convert proteids into peptones and other bodies (Penicillium, &c.); lipases, which break up fatty oils (Empusa, Phycomyces, &c.); oxydases, which bring about the oxidations and changes of colour observed in Boletus, and zymase, extracted by Buchner from yeast, which brings about the conversion of sugar into alcohol and carbondioxide.
Along this channel the nectar is drawn into the pharynx and passes, mixed with saliva, into the crop or "honey-bag"; the action of the saliva changes the saccharose into dextrose and levulose, and the nectar becomes honey, which the bee regurgitates for storage in the cells or for the feeding of the grubs.
Honey from Ogeechee Tupelo nectar will not granulate or crystallize due to its high levulose content.