DSC and protein–based time-temperature integrators: Case study of α-amylase stabilized by polyols and/or sugar
✍ Scribed by S. De Cordt; I. Avila; M. Hendrickx; P. Tobback
- Book ID
- 102772015
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 638 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0006-3592
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✦ Synopsis
Differential scanning calorimetry (DSC) was used as a tool for rapid assay of the thermostability of two Bacillus sp. a-amylases and horseradish peroxidase as a function of the concentration of glycerol, sorbitol, and sucrose. In this screening study, the DSC peak temperature proved to be a good measure of protein thermostability. By means of isothermal heating experiments, the kinetics of heat decay of B. amyloliquefaciens a-amylase were studied by following the course of the DSC peak area (heat exchange (AHlwt)) as a function of time. The high stability of this enzyme in the presence of polyolic alcohols or carbohydrates allowed working at temperatures as high as 127°C. The results of this study can have particular relevance with regard to research on and development of protein-based timetemperature integrators (TTls) for evaluating heat pasteurization or sterilization treatments of foods or pharmaceutical products. The use of the DSC peak area (AHlwt) as TTI-response was validated in experiments with a time-variable temperature profile. Finally, it was shown how the results of such non-isother-ma1 experiments can even be used for (re-)estimation of the protein decay kinetic parameters (k, ,!FA).