Honey thermal treatment effects on hydroxymethylfurfural content

The effects of honey thermal treatment on the hydroxymethylfurfural (HMF) content (temperature and time) were studied, during both transient and isothermal heating stages. Assay was carried out with two honey samples whose initial HMF values were 3.9 and 26.6 mg HMF/kg honey. During the transient stage, treatment time ranged between 14 and 60 s, and treatment final temperature ranged between 100 and 160 degreesC. This study determined that initial HMF concentration did not affect its formation kinetics. HMF content change during the isothermal stage of the thermal treatment was determined at the final temperature of the transient stage and for treatment times up to 90 s, and it follows a kinetic model of pseudo first order. First order rate constants were correlated with temperature by an Arrhenius-type equation. Thus the values of the frequency constant and activation energy were obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.