The Maillard reaction was studied in semi-industrial Manchego cheese during
ripening, through measurement of furosine and galactose. An accumulation o
f galactose was observed during the initial period of ripening, probably du
e to the inability of Streptococcus thermophilus to metabolise galactose. H
owever, a considerable decrease in galactose content and increase in furosi
ne amount were found after 15 days of ripening. No further formation of fur
osine was observed after 45 days. This fact could be attributable to the ex
haustion of galactose due to its participation in Maillard reaction and/or
its utilisation by the microorganisms Lactococcus and Lactobacillus. Furosi
ne seems to be a useful indicator of the Maillard reaction during ripening
of Manchego cheese. (C) 2000 Elsevier Science Ltd. All rights reserved.