886 19 Sugars, Sugar Alcohols and Honey
Table 19.12.Sugars identified in honey
Common name Systematic name
Glucose
Fructose
Saccharose α-D-glucopyranosyl-β-D-fructo-furanoside
Maltose O-α-D-glucopyranosyl-(1→4)-D-glucopyranose
Isomaltose O-α-D-glucopyranosyl-(1→6)-D-glucopyranose
Maltulose O-α-D-glucopyranosyl-(1→4)-D-fructose
Nigerose O-α-D-glucopyranosyl-(1→3)-D-glucopyranose
Turanose O-α-D-glucopyranosyl-(1→3)-D-fructose
Kojibiose O-α-D-glucopyranosyl-(1→2)-D-glucopyranose
Laminaribiose O-β-D-glucopyranosyl-(1→3)-D-glucopyranose
α,β-Trehalose α-D-glucopyranosyl-β-D-glucopyranoside
Gentiobiose O-β-D-glucopyranosyl-(1→6)-D-glucopyranose
Melezitose O-β-D-glucopyranosyl-(1→3)-O-β-D-fructofuranosyl-(2→1)-α-D-glucopyranoside
3-α-Isomaltosylglucose O-α-D-glucopyranosyl-(1→6)-O-α-D-glucopyranosyl-(1→3)-D-glucopyranose
Maltotriose O-α-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→4)-D-gluco-pyranose
1-Kestose O-α-D-glucopyranosyl-(1→2)-β-D-α-fructofuranosyl-(1→2)-β-D-fructofuranoside
Panose O-α-D-glucopyranosyl-(1→6)-O-α-D-glucopyranosyl-(1→4)-D-glucopyranose
Isomaltotriose O-α-D-glucopyranosyl-(1→6)-O-α-D-glucopyranosyl-(1→6)-D-glucopyranose
Erlose O-α-D-glucopyranosyl-(1→4)-α-D-glucopyranosyl-β-D-fructofuranoside
Theanderose O-α-D-glucopyranosyl-(1→6)-α-D-glucopyranosyl-β-D-fructofuranoside
Centose O-α-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→2)-D-glucopyranose
Isopanose O-α-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→6)-D-gluco-pyranose
Isomaltotetraose O-α-D-glucopyranosyl-(1→6)-[O-α-D-glucopyranosyl-(1→6)] 2 - D-gluco-pyranose
Isomaltopentaose O-α-D-glucopyranosyl-(1→6)-[O-α-D-glucopyranosyl-(1→6)] 3 - D-gluco-pyranose
the plants from which the honey was derived,
while geographical and seasonal effects are neg-
ligible. The content of sucrose varies appreciably
with the honey ripening stage.
19.2.1.5.3 Enzymes
The most prominent enzymes in honey are
α-glucosidase(invertase or saccharase),α-and
β-amylases (diastase), glucose oxidase, catalase
and acid phosphatase. Average enzyme activities
are presented in Table 19.14. Invertase and dias-
tase activities, together with the hydroxymethyl
furfural content, are of significance for assessing
whether or not the honey was heated.
Forα-glucosidase, 7−18 isoenzymes are known.
In a wide pH optimum between 5. 8 − 6 .5theen-
zyme hydrolyzes maltose and otherα-glucosides.
The KMwith sucrose as substrate is 0.030 mol/l.
It also possesses transglucosylase activity. Dur-
ing the first stage of sucrose hydrolysis the trisac-
charide erlose (α-maltosyl-β-D-fructofuranoside)
plus other oligosaccharides are formed (E = en-
zyme, S = sucrose, G = glucose, F = fructose):(19.3)As the hydrolysis proceeds, most of these
oligosaccharides are cleaved into monosaccha-
rides.
Thermal inactivation of invertase in honey and its
half-life values at various temperatures have been
thoroughly investigated. These data are presented
in Figs. 19.12 and 19.13. Practically all invertase
activity is derived from bees.
Honey α-andβ-amylases (diastase) also
originate from bees. Their pH optimum range