Comparative study of pH and high pressure treatment on the viscoelastic properties of glucomannan gels after long-term frozen storage
Four lots of glucomannan (GM) gels (5 g/100 mL w/v): two lots of native GM gels (pH = 6.6; lot N) and two lots of deacetylated GM gels (pH = 11; lot D) were subjected to high hydrostatic pressure (HHP) at 0 (N0 and D0 respectively), and 400 MPa (N400 and D400 respectively). All samples were frozen a...
| Autores: | , , |
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| Formato: | artículo |
| Estado: | Versión enviada para evaluación y publicación |
| Fecha de publicación: | 2017 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/171249 |
| Acesso em linha: | http://hdl.handle.net/10261/171249 |
| Access Level: | acceso abierto |
| Palavra-chave: | Frozen storage High hydrostatic pressure Glucomannan |
| Resumo: | Four lots of glucomannan (GM) gels (5 g/100 mL w/v): two lots of native GM gels (pH = 6.6; lot N) and two lots of deacetylated GM gels (pH = 11; lot D) were subjected to high hydrostatic pressure (HHP) at 0 (N0 and D0 respectively), and 400 MPa (N400 and D400 respectively). All samples were frozen and stored at −20 °C for two years to analyse the effect of long-term frozen storage on the viscoelastic parameters of pressurized samples according to pH (FN400, FD400) vs unpressurized samples (FN0, FD0), all in comparison with the respective unfrozen unpressurized controls (N0, D0). HHP improved the gel properties of frozen native gels as evidenced by significantly higher stress (σ) and strain (γ) amplitudes in FN400 vs FN0, albeit the effect was attenuated when GM was deacetylated (FD400 vs FD0). From T > 65 °C, HHP produced rubber-like elasticity in native GM gel (N400), and this thermal response was maintained in frozen native gel (FN400). Thermal profiles of deacetylated GM gels suggest that HHP reduced vitrification of physical networks in FD400 vs FD0. |
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