title: Kinetics of anthocyanin degradation and browning in reconstituted blackberry juice treated at high temperatures (100-180 degrees C).
abstract: Monomeric anthocyanin degradation and nonenzymatic browning (NEB) index have been determined in reconstituted blackberry juice heated at high temperature in a hermetically sealed cell. Statistical analysis demonstrated that, when the temperature range (100-180 degrees C) was divided into two subranges (100-140 and 140-180 degrees C) for anthocyanin degradation, reaction kinetics were well represented by two sequential first-order reactions. The activation energy for NEB from 100 to 180 degrees C (106 kJxmol(-1)) was slightly higher than the anthocyanin value at the lower temperature range (92 kJxmol(-1)), but was more than twice the value for the higher range (44 kJxmol(-1)). The reaction rate constant at 140 degrees C for anthocyanin degradation (3.5 x 10(-3) s(-1)) was two times that for the NEB index (1.6 x 10(-3) s(-1)). Hence, anthocyanin degradation was faster than the appearance of NEB products. The non-isothermal method developed allows estimating kinetic parameters and thereby generating temperature profiles of heat processes that would help preserve the nutritional properties of foods during high-temperature processes.
authors.affiliation: Escuela de Tecnologia de Alimentos, Universidad de Costa Rica, Apartado Postal 11501-2060, San Jose, Costa Rica.
authors.forename: Nadiarid
authors.initials: N
authors.lastname: Jiménez
authors.forename: Philippe
authors.initials: P
authors.lastname: Bohuon
authors.forename: Janice
authors.initials: J
authors.lastname: Lima
authors.forename: Manuel
authors.initials: M
authors.lastname: Dornier
authors.forename: Fabrice
authors.initials: F
authors.lastname: Vaillant
authors.forename: Ana Mercedes
authors.initials: AM
authors.lastname: Pérez
mesh_terms: D000872:Anthocyanins / Q000032:analysis* / Q000737:chemistry; D001628:Beverages / Q000032:analysis*; D002151:Calorimetry; D032084:Citrus sinensis; D005638:Fruit / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D015416:Maillard Reaction; D027843:Vitis
chemical_list: D000872:Anthocyanins