Nineteen commercial samples (with a shelf-life of 2 years) and two artisana
l samples (freshly collected and stored for 1 year respectively) of Spanish
honeys were analysed for pH, protein content and furosine content. Most of
the samples had pH values and protein contents within the limits reported
in the literature. The presence of furosine was confirmed by comparison of
its retention time with that of a furosine standard and by HPLC-MS. The lev
el of furosine in the samples studied ranged from 4.32 to 13.62 g kg(-1) pr
otein. The lowest furosine value was observed in the freshly collected arti
sanal sample. Heat treatment under severe conditions (90 degreesC for up to
135 min) increased the furosine content from 4.43 to 14.38 g kg(-1) protei
n. The results show that furosine seems to be a promising indicator to dete
ct overheating during honey manufacture. (C) 2001 Society of Chemical indus
try.