Pectin methylesterase inactivation by pulsed light
Pectinmethylesterase (PME) is a degradative enzyme of the cloudiness of fruit juices. Pulsed light (PL) is a non-thermal technology able to inactivate enzymes. This work aimed to assess the potential inactivation of PME by PL and to explain how it occurs. To this, a suspension of the enzyme was trea...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad Católica San Antonio de Murcia (UCAM) |
| Repositorio: | RIUCAM. Repositorio Institucional de la Universidad Católica San Antonio de Murcia |
| OAI Identifier: | oai:repositorio.ucam.edu:10952/4825 |
| Acceso en línea: | http://hdl.handle.net/10952/4825 |
| Access Level: | acceso abierto |
| Palabra clave: | Pulsed light Pectinmethylesterase Enzyme inactivation Protein structure Inactivation kinetics Fruit juices |
| Sumario: | Pectinmethylesterase (PME) is a degradative enzyme of the cloudiness of fruit juices. Pulsed light (PL) is a non-thermal technology able to inactivate enzymes. This work aimed to assess the potential inactivation of PME by PL and to explain how it occurs. To this, a suspension of the enzyme was treated with PL up to 128 J/cm2. The inactivation curve was built and structural changes were determined by far-UV circular dichroism, intrinsic and extrinsic fluorescence and spectrophotometry. Furthermore, the presence/absence of unfolding intermediaries was assessed by phase-diagram analysis. PL was able to inactivate PME with a first-order kinetic rate of 0.034 cm2/J. The inactive protein seemed to have a molten-globule structure, due to the conserved secondary structure and modified tertiary structure. Phase diagram data fitted a single line, which is consistent with absence of unfolding intermediaries. A significant increase in absorbance at 420 nm (p<0.05) showed that PL promoted enzyme aggregation. |
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