The quality degradation of pineapple juice due to heat treatment was studied at temperatures ranging from 55 to 95 C. The changes in Hunter parameters a and b followed first order kinetics while the change in parameter L could not be fitted to any simple relationship.
Total color difference ðDEÞ could be described using a combined model which included the effect of both nonenzymatic browning and pigment destruction.
The changes of 5-hydroxymethylfurfural (HMF) and brown pigment formation were chosen to demonstrate the non-enzymatic browning reaction occurring during the study and were found to follow zero order kinetics. The results suggested that processing temperatures strongly influenced the reaction rate. The Arrhenius model could be
used to describe the temperature dependence of the reaction rate constant for all parameters considered. A
study of quality loss in terms of sugars and amino acids, the substrates of the Maillard reaction, together with
carotenoid destruction as affected by heat treatment is recommended for future work.