2009_Book_FoodChemistry

886 19 Sugars, Sugar Alcohols and Honey
Table 19.12. Sugars identified in honey
Common name
Glucose
Fructose
Saccharose
Maltose
Isomaltose
Maltulose
Nigerose
Turanose
Kojibiose
Laminaribiose
α,β-Trehalose
Gentiobiose
Melezitose
3-α-Isomaltosylglucose
Maltotriose
1-Kestose
Panose
Isomaltotriose
Erlose
Theanderose
Centose
Isopanose
Isomaltotetraose
Isomaltopentaose
Systematic name
α-D-glucopyranosyl-β-D-fructo-furanoside
O-α-D-glucopyranosyl-(1 → 4)-D-glucopyranose
O-α-D-glucopyranosyl-(1 → 6)-D-glucopyranose
O-α-D-glucopyranosyl-(1 → 4)-D-fructose
O-α-D-glucopyranosyl-(1 → 3)- D-glucopyranose
O-α-D-glucopyranosyl-(1 → 3)-D-fructose
O-α-D-glucopyranosyl-(1 → 2)-D-glucopyranose
O-β-D-glucopyranosyl-(1 → 3)-D-glucopyranose
α-D-glucopyranosyl-β-D-glucopyranoside
O-β-D-glucopyranosyl-(1 → 6)-D-glucopyranose
O-β-D-glucopyranosyl-(1 → 3)-O-β-D-fructofuranosyl-(2 → 1)-α-D-glucopyranoside
O-α-D-glucopyranosyl-(1 → 6)-O-α-D-glucopyranosyl-(1 → 3)-D-glucopyranose
O-α-D-glucopyranosyl-(1 → 4)-O-α-D-glucopyranosyl-(1 → 4)-D-gluco-pyranose
O-α-D-glucopyranosyl-(1 → 2)-β-D-α-fructofuranosyl-(1 → 2)-β-D-fructofuranoside
O-α-D-glucopyranosyl-(1 → 6)-O-α-D-glucopyranosyl-(1 → 4)-D-glucopyranose
O-α-D-glucopyranosyl-(1 → 6)-O-α-D-glucopyranosyl-(1 → 6)-D-glucopyranose
O-α-D-glucopyranosyl-(1 → 4)-α-D-glucopyranosyl-β-D-fructofuranoside
O-α-D-glucopyranosyl-(1 → 6)-α-D-glucopyranosyl-β-D-fructofuranoside
O-α-D-glucopyranosyl-(1 → 4)-O-α-D-glucopyranosyl-(1 → 2)-D-glucopyranose
O-α-D-glucopyranosyl-(1 → 4)-O-α-D-glucopyranosyl-(1 → 6)-D-gluco-pyranose
O-α-D-glucopyranosyl-(1 → 6)-[O-α-D-glucopyranosyl-(1 → 6)] 2 -D-gluco-pyranose
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 negligible.
The content of sucrose varies appreciably
with the honey ripening stage.
plus other oligosaccharides are formed (E = enzyme,
S = sucrose, G = glucose, F = fructose):
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 diastase
activities, together with the hydroxymethyl
furfural content, are of significance for assessing
whether or not the honey was heated.
For α-glucosidase, 7−18 isoenzymes are known.
In a wide pH optimum between 5.8−6.5 theenzyme
hydrolyzes maltose and other α-glucosides.
The K M with sucrose as substrate is 0.030 mol/l.
It also possesses transglucosylase activity. During
the first stage of sucrose hydrolysis the trisaccharide
erlose (α-maltosyl-β-D-fructofuranoside)
(19.3)
As the hydrolysis proceeds, most of these
oligosaccharides are cleaved into monosaccharides.
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- and β-amylases (diastase) also
originate from bees. Their pH optimum range