Effect of deacetylation degree of chitosan on rheological properties and physical chemical characteristics of genipin-crosslinked chitosan beads
| Autor: | Loleny Tavares, Elí Emanuel Esparza Flores, Rafael C. Rodrigues, Caciano Pelayo Zapata Noreña, Plinho Francisco Hertz |
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| Rok vydání: | 2020 |
| Předmět: |
Thermogravimetric analysis
Materials science 010304 chemical physics Scanning electron microscope General Chemical Engineering 04 agricultural and veterinary sciences General Chemistry 040401 food science 01 natural sciences Chitosan chemistry.chemical_compound Hydrolysis 0404 agricultural biotechnology Chemical engineering chemistry Rheology 0103 physical sciences Genipin Fourier transform infrared spectroscopy Elastic modulus Food Science |
| Zdroj: | Food Hydrocolloids. 106:105876 |
| ISSN: | 0268-005X |
| DOI: | 10.1016/j.foodhyd.2020.105876 |
| Popis: | The effect of the degree of deacetylation (DD) on the characteristics of the support matrix formed through chitosan (CH) and genipin (GE) crosslinking was investigated by using CH with DD of 83, 94 and 96%. The rheological properties of CH dispersions were determined in order to study the influence of DD on the CH viscosity, gel network structures and gelation temperature (Tgel). The CH exhibited the shear-thinning behavior of pseudoplastic fluids. Tgel decreased with the increase of DD and the sol-gel transition temperature of CH-83, CH-94 and CH-96 were 75, 30 and 25 °C, respectively. The magnitude of viscous modulus (G’’) was higher than the elastic modulus (G’), revealing the formation of a weak gel structure. The CH dispersions have been used in the preparation of beads and then crosslinked with GE to form support matrices. Besides, to verify how it influences in a practical application, an enzymatic immobilization was carried out using a β- d -galactosidase (BG) as a model, which could be advantageously employed to promote hydrolysis of lactose. Scanning Electron Microscope images showed biocatalysts with multiple porous compartments. Fourier Transform Infrared Spectroscopy (FTIR) analyses confirmed chemical and physical interactions between CH, GE and BG. Thermogravimetric analysis (TGA) demonstrated that the DD of CH had a positive influence in the thermal degradation behavior of the biocatalysts up to 200 °C, which represents the temperature range used in most enzymatic reactions (up to 100 °C) in the industrial scale applications. |
| Databáze: | OpenAIRE |
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