The kinetic parameters of surface color degradation of canned fresh green peas sterilized in a rotary retort, using the a* value from a
spectrophotometer as the physical parameter and the concept of fractional conversion in conditions of unsteady state were determined in
the range of retort temperatures of 120 and 131 1C. Experimental initial a* values fluctuated between 14.4 and 15.7, while final a*
values ranged between 0.165 and 4.75. After five iterations performed, solving simultaneously the energy balance of the system, the
differential equation of unsteady conduction for spheres and the first-order degradation reaction of surface color by numerical methods,
the best values of k100 1C and Ea determined were 5.48104 s1 and 89.37 kJ/mol respectively, being 5.68% the deviation between
experimental and predicted fractional retentions of a* with the determined parameters.
r 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.