Characterization of Polyphenol Oxidase from the Manzanilla Cultivar (Olea europaea pomiformis) and Prevention of Browning Reactions in Bruised Olive Fruits
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- 作者：Kharla A. Segovia-Bravo ; Manuel Jaré ; n-Galá ; n ; Pedro Garcí ; a-Garcí ; a ; Antonio Garrido-Ferná ; ndez
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：August 8, 2007
- 年：2007
- 卷：55
- 期：16
- 页码：6515 - 6520
- 全文大小：113K
- 年卷期：v.55,no.16(August 8, 2007)
- ISSN：1520-5118
文摘
The crude extract of the polyphenol oxidase (PPO) enzyme from the Manzanilla cultivar (Oleaeuropaea pomiformis) was obtained, and its properties were characterized. The browning reactionfollowed a zero-order kinetic model. Its maximum activity was at pH 6.0. This activity was completelyinhibited at a pH below 3.0 regardless of temperature; however, in alkaline conditions, pH inhibitiondepended on temperature and was observed at values above 9.0 and 11.0 at 8 and 25 
C, respectively.The thermodynamic parameters of substrate oxidation depended on pH within the range in whichactivity was observed. The reaction occurred according to an isokinetic system because pH affectedthe enzymatic reaction rate but not the energy required to carry out the reaction. In the alkaline pHregion, browning was due to a combination of enzymatic and nonenzymatic reactions that occurredin parallel. These results correlated well with the browning behavior observed in intentionally bruisedfruits at different temperatures and in different storage solutions. The use of a low temperature (
8C) was very effective for preventing browning regardless of the cover solution used.
C, respectively.The thermodynamic parameters of substrate oxidation depended on pH within the range in whichactivity was observed. The reaction occurred according to an isokinetic system because pH affectedthe enzymatic reaction rate but not the energy required to carry out the reaction. In the alkaline pHregion, browning was due to a combination of enzymatic and nonenzymatic reactions that occurredin parallel. These results correlated well with the browning behavior observed in intentionally bruisedfruits at different temperatures and in different storage solutions. The use of a low temperature (8C) was very effective for preventing browning regardless of the cover solution used.