Covalent immobilization of papain onto poly(hydroxyethyl methacrylate)-chitosan cryogels for apple juice clarification
Autor: | Rukiye Yavaşer, Arife Alev Karagözler |
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Rok vydání: | 2020 |
Předmět: |
Immobilized enzyme
Food Handling General Chemical Engineering 02 engineering and technology (Hydroxyethyl)methacrylate 010402 general chemistry 01 natural sciences Industrial and Manufacturing Engineering Chitosan chemistry.chemical_compound Support materials Papain Organic chemistry chemistry.chemical_classification Chemistry Hydrogen-Ion Concentration 021001 nanoscience & nanotechnology Enzymes Immobilized 0104 chemical sciences Fruit and Vegetable Juices Enzyme Covalent bond Malus Methacrylates Juice clarification 0210 nano-technology Cryogels Food Science |
Zdroj: | Food science and technology international = Ciencia y tecnologia de los alimentos internacional. 26(7) |
ISSN: | 1532-1738 |
Popis: | Enzyme immobilization appears as a remarkable technique to safely attach enzymes for several applications and cryogels stand as promising support materials to be used in such investigations. In this work, papain enzyme was immobilized onto an interpenetrating network obtained by cryogelation of N,N′-methylenebisacrylamide cross-linked 2-hydroxyethyl methacrylate and glutaraldehyde cross-linked chitosan. Cryogels were modified with –NH2 functionality and glutaraldehyde in order to attach papain covalently. Immobilization was carried out at 25 ℃ in 0.1 M pH 7.0 phosphate buffer at 1.0 mg/ml enzyme concentration for 5 h. The amount of papain immobilized onto cryogel was calculated to be 15.2 ± 2.54 mg/g cryogel. Macroporous structure and surface area were determined by scanning electron microscopy and Brunauer–Emmett–Teller techniques, respectively. Energy dispersive X-ray analysis showed that papain was bound to the cryogel and cryogel structure was composed of 2-hydroxyethyl methacrylate, chitosan, and glutaraldehyde. Proteolytic activities of free and immobilized papain were measured using casein as substrate. Optimum pH values and temperatures were 8.0 and 65 ℃ for free and immobilized enzymes and kinetic parameters were calculated at these conditions. Reusability and storage stability results indicated that immobilization enhanced the stability of papain compared to free form. Efficiency of immobilized papain was demonstrated by apple juice clarification study as an industrial use of the enzyme. Phenolic compound, protein, total soluble solid contents, and viscosity of apple juice before and after clarification were determined. |
Databáze: | OpenAIRE |
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