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Neves,Valdir Augusto; Picchi,Douglas Gatte; Silva,Maraiza Aparecida da. |
Polyphenoloxidase (PPO; EC 1.14.18.1) extracted from Mentha arvensis leaves was isolated by (NH4)2SO4 precipitation and extensive dialysis. Its optimum pH and temperature varied with the substrate. The PPO showed activity with various diphenols. Km values were found 0.825, 0.928 and 7.41mM for caffeic acid, 4-methylcatechol and catechol, respectively. On heat-inactivation, half of the activity was lost after 60 and 15 sec at 70 and 75ºC, respectively. Measuring of residual activity showed a stabilizing effect of sucrose at various temperatures with activation energy (Ea) for inactivation increasing with sucrose concentration from 0 to 40% (w/w). Ea values of 78.13; 80.37; 82.79 and 81.00 kJ/Mol were found for 0, 15; 30 and 40% sucrose, respectively. PPO... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Polyphenoloxidase; Mentha arvensis; Characterization; Heat inactivation; Inhibitors. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000400025 |
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Troiani,Estela de Pieri; Tropiani,Clariza Tomé; Clemente,Edmar. |
The enzimatic activity of peroxidase (POD) and polyphenoloxidase (PPO) extracted from three grape cultivars (Vitis vinifera L.), cultivated in Marialva city, state of Paraná, was evaluated in this study. The enzymatic extracts were prepared starting from the Rubi, Borbon and Benitaka grape cultivars pulp and peel. The activity of the peroxidase was 53.00 units/100 g in the extract from the Rubi cultivar peel, and 327.00 units/100 g from the Benitaka cultivar, these values being superior to those observed in the same cultivars pulp extracts, which were 7.67 units/100 g and 44.00 units/100 g respectively. However, the result was opposite in the Borbon cultivar, with values of 141.11 units/100 g in the pulp and 11.50 units/100 g in the peel being found. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Peroxidase; Polyphenoloxidase; Activity; Grape; Vitis vinifera. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542003000300019 |
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Li,Peiqin; Luo,Haiyu; Meng,Jiajia; Sun,Weibo; Wang,Xiaohan; Lu,Shiqiong; Peng,Youliang; Zhou,Ligang. |
Background Three oligosaccharides (EOS, WOS and SOS) were respectively prepared from the corresponding polysaccharides, namely exopolysaccharide (EPS), water-extracted mycelial polysaccharide (WPS) and sodium hydroxide-extracted mycelial polysaccharides (SPS) from the endophytic fungus Fusarium oxysporum Dzf17. In this study, the effects of EOS, WOS and SOS on the activities of the defense-related enzymes, namely phenylalanine ammonia lyase (PAL), polyphenoloxidase (PPO) and peroxidase (POD) in its host plant Dioscorea zingiberensis cultures were investigated. Results For the suspension cell cultures of D. zingiberensis, the highest PAL activity was induced by 0.5 mg/mL of WOS at 48 h after treatment, which was 4.55-fold as that of control. Both PPO and... |
Tipo: Journal article |
Palavras-chave: Endophytic fungus; Phenylalanine ammonia lyase; Peroxidase; Polyphenoloxidase; Polysaccharide. |
Ano: 2014 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582014000400003 |
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