RESUMO -Este trabalho foi realizado com o objetivo de avaliar o efeito de atmosferas controladas contendo diferentes concentrações de oxigênio sobre a atividade das enzimas β-galactosidase e pectina metilesterase, e sobre a cor da casca e a firmeza da polpa de mamões 'Golden'. Os frutos foram mantidos por 36 dias, nas seguintes atmosferas controladas: 1% de O 2 e 0,03% CO 2 com adsorvedor de etileno, 3% de O 2 e 0,03% de CO 2 com adsorvedor de etileno, 5% O 2 e 0,03% de CO 2 com adsorvedor de etileno e atmosfera ambiente sem adsorvedor de etileno. A UR e a temperatura foram mantidas entre 85-95% e a 13 o C, respectivamente. Os frutos estocados sob atmosfera de 1% de O 2 e 0,03% CO 2 apresentaram retardamento nas atividades das enzimas β-galactosidase e pectina metilesterase comparado com os frutos estocados nas outras atmosferas avaliadas. Os frutos armazenados sob atmosfera de 1% de O 2 e 0,03% O 2 também apresentaram atraso no desenvolvimento da cor da casca e amolecimento da polpa. Termos para indexação: Carica papaya, atmosfera controlada, β-galactosidase, pectinametilesterase, firmeza de polpa.
ACTIVITY OF PECTIN METHYLESTERASE AND β-GALACTOSIDASE ENZYMES IN 'GOLDEN' PAPAYA STORED UNDER DIFFERENT OXYGEN CONCENTRATIONSABSTRACT -This study was carried out with the objective to evaluate the effect of controlled atmospheres containing different concentration of oxygen on the activity of β-galactosidase and pectinmethylesterase enzymes, on the skin color and pulp firmness in 'Golden' papaya. The fruits were kept for 36 days under the following controlled atmospheres: 1% of O 2 and 0.03% CO 2 with ethylene absorber, 3% of O 2 and 0.03% of CO 2 with ethylene absorber, 5% O 2 and 0.03% of CO 2 with ethylene absorber and environmental atmosphere without ethylene absorber. Relative humidity was set at the range 85-95% and temperature maintained at 13 o C. Fruit stored under atmospheres of 1% of O 2 and 0.03% CO 2 had a β-galactosidase and pectimethylesterase activities delayed compared with the fruits storage under the other atmospheres evaluated. There was also, a delay in the development of color and pulp softening in fruits stored under atmospheres of 1% of O 2 and 0.03% O 2 .