Abstract:

A model solution of orange juice containing sugars, amino acids, ascorbic acid and citric acid was prepared. The
formation of non-enzymatic browning reaction products including 3-hydroxy-2-pyrone（3OH2P), 5-hydroxymethylfurfural
(5-HMF) and furfural (2-F) was examined during storage, and meanwhile the correlation analysis of browning evaluation
criteria including absorbance value at 420 nm (A420 nm), browning index (BI) and total color difference(ΔE) were also
measured. The results indicated that 5-HMF and 3OH2P mainly derived from fructose and ascorbic acid, respectively, while
the formation of 2-F was stimulated by sugars. Significant positive correlations (P < 0.05) were found among A420 nm, BI and
ΔE in system containing sugars, but no significant relationship (P > 0.05) was found in system lacking sugars.

Key words: model system, orange juice, non-enzymatic browning, evaluation criteria, correlation analysis