2009_Book_FoodChemistry

4.2 Monosaccharides 279
glycosidic bond. β-Galactosyl-isomaltol was
detected as the main product in heated milk.
However, glucosyl-isomaltol is formed from
maltose in much lower amounts. In this case, the
formation of maltol dominates. The galactosyl
residue clearly favors the formation of furanoid
1-deoxyosone from lactose, whereas the pyranoid
1-deoxyosone is preferentially formed from
maltose (cf. Formula 4.76 and 4.77).
An open-chain compound, the lactic acid
ester of β-hydroxypropionic acid (VIII in
Formula 4.67) can also be formulated from
1-deoxyosone via 1,5-dideoxyosone. Hydration
of this β-dicarbonyl compound and
subsequent cleavage of the bond between C-2
and C-3 directly yield the lactic acid ester
(Formula 4.78). Among the compounds mentioned,
acetylformoin is one of the comparatively
(4.75)
(4.76)
(4.77)
(4.78)