Chemical and Functional Properties of Food Saccharides

© 2004 by CRC Press LLC
easily eliminate the sugar residue, yielding pyridones (18.62). In an excess of amine
pyridone, imines (18.63) might be formed, which can participate in protein cross-
linking. Under slightly alkaline conditions, isomerization of pyridinium betaines
(18.61) yields glycosylpyridones (18.64). 57 Another degradation product of 1-deoxy-
2,3-diuloses specific for disaccharide is 3(2H)-furanone (18.65). 58 This compound
derived from lactose was recently identified in milk. 59
18.7 DEGRADATION OF 1-AMINO-1,4-DIDEOXYDIKETOSES
O
The aminoreductones of Type 66 were identified only recently in reaction mixtures
containing disaccharides and primary amines or amino acids. 28,60 These aminoreductones
can be considered as the first stable tautomers of 1-amino-1,4-dideoxy-
2,3-diuloses (18.19) and are also formed as derivatives of lysine side chains of
proteins. 28 Due to their aminoreductone structure, these compounds undergo further
reactions, including redox reactions.
OH
N
R'
18.62
RO
N
R'
CH 3
R'
N
OH
18.63
O
N
R'
18.64
CH2 O
OH
CH 3
OR
CH 3
O
18.65
CH 3