Pectin methylesterase activity determined by different methods and thermal inactivation of exogenous pme in mango juice

Ciência e Agrotecnologia

Samantha Lemke Gonzalez²  Regina Cristina Aparecida Lima¹  Eliana Beleski Borba Carneiro¹  Mareci Mendes De Almeida¹  Neiva Deliberali Rosso¹ 

[1] ,Universidade Federal de Santa CatarinaFlorianópolis SC

关键词: Pectin metilesterase;    activity;    thermal inactivation;    mango juice;    Pectina metilesterase;    atividade;    inativação térmica;    suco de manga;   

DOI  :  10.1590/S1413-70542011000500017

来源: SciELO

【 摘 要 】

Pectin methylesterase (PME) hydrolyzes methyl ester groups in pectin chains to form carboxylic groups, releasing methanol and H3O+. The aim of this study was to determine PME activity in samples of pectinases by UV-VIS spectroscopy, to measure the acid and methanol produced in the reaction of pectin with pectinase and to verify the thermal inactivation of exogenous PME in mango juice. The activity of PME in samples of pectinase was determined by potentiometry, UV-VIS spectroscopy, and by the action of alcohol oxidase. The reaction showed greater activity at pH 4.0 to 4.5 and at a temperature of 45° C. PME activity determined by UV-VIS spectroscopy with bromophenol blue indicator showed a good correlation with the activity determined by potentiometry and with alcohol oxidase. The results showed that bromophenol blue indicators can be used to determine PME activity in samples of pectinases where the optimum pH is located in the acidic range. The thermal inactivation of exogenous PME in mango juice occurred at 75° C for 20 min of exposure.

【 授权许可】

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