Formation of Amadori compounds in dehydrated fruits

The presence of Amadori compounds in commercial dehydrated fruits has been shown through HPLC analysis of the corresponding 2-furoylmethyl-amino acids obtained by acid hydrolysis. Furosine (2-furoylmethyl-lysine) was the main 2-furoylmethyl derivative observed in dried figs and apricot samples, whereas in prunes and dates similar amounts of furosine and 2-furoylmethyl-gamma-aminobutyric acid were detected. A considerable variation of 2-furoylmethyl-amino acid contents among commercial raisin samples was observed. 2-Furoylmethyl-gamma-aminobutyric acid and 2-furoylmethyl-arginine, the most abundant 2-furoylmethyl-amino acids, ranged between 9.9 and 75.8 mg/100 g sample and 10.0 and 62.5 mg/100 g sample, respectively. Most of the Amadori compounds present in raisins seem to have originated during the commercial shelf life period rather than during processing. Determination of 2-furoylmethyl-amino acids could be used as a method of controlling commercial dehydrated fruit and selecting storage conditions.