Extraction, Purification and Thermodynamic Characterization of Almond (Amygdalus communis) β-Galactosidase for the Preparation of Delactosed Milk
Buffer type, pH and ionic strength, as well as the fraction of polyvinylpyrrolidone were optimized for efficient extraction of β-galactosidase from almond seeds. The enzyme was purified up to electrophoretic homogeneity employing (NH4)2SO4 (15–60 %) fractionation, size exclusion and ion-exchange chr...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
University of Zagreb
2013-01-01
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| Series: | Food Technology and Biotechnology |
| Subjects: | |
| Online Access: | http://hrcak.srce.hr/file/146868 |
| Summary: | Buffer type, pH and ionic strength, as well as the fraction of polyvinylpyrrolidone were optimized for efficient extraction of β-galactosidase from almond seeds. The enzyme was purified up to electrophoretic homogeneity employing (NH4)2SO4 (15–60 %) fractionation, size exclusion and ion-exchange chromatography. Molecular mass of β-galactosidase as estimated by gel filtration and SDS-PAGE was approx. 62 kDa, confirming its monomeric nature. The optimum activity of the enzyme was at pH=5.5, and it was stable within the range of pH=5.0–6.0. Various kinetic parameters of β-galactosidase thermal inactivation were calculated: ΔH°, ΔS° and ΔG° suggested that the enzyme undergoes significant processes of unfolding during denaturation. Using β-galactosidase from almond seed powder, lactose hydrolysis in milk up to approx. 50 % was observed. The findings indicate the potential use of almond seeds for the production of low/delactosed milk for lactose-intolerant population. |
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| ISSN: | 1330-9862 1334-2606 |