Please use this identifier to cite or link to this item
|title: ||Effect of Water Content on the Thermal Inactivation Kinetics of Horseradish Peroxidase Freeze-Dried from Alkaline pH|
|authors: ||Lemos, M. A.|
Oliveira, J. C.
Saraiva, J. A.
|keywords: ||enzyme inactivation|
protein thermal denaturation
|issue date: ||2001|
|publisher: ||SAGE Publications|
|abstract: ||The thermal inactivation of horseradish peroxidase freeze-dried from solutions of different pH (8, 10 and 11.5, measured at 25 C) and equilibrated to different water contents was studied in the temperature range from 110 to 150 C. The water contents studied (0.0, 1.4, 16.2 and 25.6 g water per 100 g of dry enzyme) corresponded to water activities of 0.0, 0.11, 0.76 and 0.88 at 4 C. The kinetics were well described by a double exponential model. The enzyme was generally more stable the lower the pH of the original solution, and for all pH values, the maximum stability was obtained at 1.4 g water/100 g dry enzyme. Values of z were generally independent of water content and of the pH of the original solution, and in the range of 15–25 °C, usually found in neutral conditions, with the exception of the enzyme freeze dried from pH 11.5 and equilibrated with phosphorus pentoxide, where a z-value of the stable fraction close to 10 C was found.|
|publisher version/DOI: ||http://dx.doi.org/10.1106/E9NW-1TB4-KU4W-8X7M|
|source: ||Food Science and Technology International|
|appears in collections||QOPNA - Artigos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.