Polyphenoloxidase and peroxidase in avocado pulp (Persea americana Mill.)
2010
Vanini, Lucimara Salvat(State University of Maringá Chemistry Department Laboratory of Food Biochemistry) | Kwiatkowski, Angela(State University of Maringá Chemistry Department Laboratory of Food Biochemistry) | Clemente, Edmar(State University of Maringá Chemistry Department Laboratory of Food Biochemistry)
English. The aim of the present investigation was to evaluate the enzymatic activity of polyphenoloxidase and peroxidase in avocado pulps, from the Northwest area of Paraná-Brazil, in order to compare the varieties on their enzymatic activity for both, minimum and industrial processing. Enzymatic extracts were prepared from avocado pulp of Choquete, Fortuna and Quintal varieties, in green and ripe maturation stage. Thermal treatment was applied with temperatures 60, 65, 70, 75 and 80 °C. The enzymatic activities were determined by using spectrophotometer. A decline of polyphenoloxidase activity was observed in all of the varieties when both, temperature and time increased. Total inactivation of enzymes was not observed in the largest temperature. Fortuna and Choquete variety showed the lowest polyphenoloxidase activity in the ripe stage. Soluble peroxidase showed activity in the green stage, whereas, ionically bound peroxidase activity increased with the change from green to ripe maturation stage in Choquete variety.
Show more [+] Less [-]Portuguese. O objetivo foi avaliar a atividade enzimática da polifenoloxidase (PPO) e da peroxidase (POD) em polpas de abacates, da região Noroeste do Paraná, Brasil, visando comparar as variedades e suas atividades enzimáticas para processamento mínimo ou industrial. Extratos enzimáticos foram preparados da polpa de abacate das variedades Choquete, Fortuna e Quintal no estágio de maturação verde e maduro. Foi aplicado tratamento térmico com temperaturas de 60, 65, 70, 75 e 80 °C. As atividades enzimáticas foram determinadas por espectrofotometria. Observou-se declínio da atividade da PPO, à medida que aumentava a temperatura e o tempo em todas as variedades. Não foi observada inativação total das enzimas na maior temperatura. As variedades Fortuna e Choquete apresentaram menor atividade da PPO no estágio maduro. A POD solúvel apresentou menor atividade no estágio verde, e, atividade da POD ionicamente ligada aumentou com a mudança do estágio verde para maduro para a variedade Choquete.
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