ISSN:
1365-2621
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
Notizen:
A method of controlling the porosity of cellular solid foods and its dependence on solids content were investigated. Freeze-dehydration of cold-set alginate gels was used to produce tailor-made porous solids. Gels were composed of sodium alginate, corn starch, oil and other additives necessary to induce gelation. Porosity values were derived from particle and bulk densities utilizing a helium pycnometer and a volumetric displacement method. To achieve a wider range of porosities, the gels were immersed in sucrose solutions of 10 to 60 8Bx. Gel porosity after drying decreased from 0.85 to 0.42 and 0.07 after immersion in the 30 and 60 8Bx solution for 183 and 158 h, respectively. Similarly, after immersing gels containing an additional 5% soy oil, porosity decreased to 0.36 and 0.04 after 165 and 158 h, in 30 and 60 8Bx solution, respectively. Preparation and formulation play a significant role in porosity, and they can both be utilized to control its value within the range 0.85–0.04. SEM micrographs revealed changes in the original cellular solid, characterized by numerous large void spaces, to a denser and more uniform appearance of the specimen after immersion in the 60 8Bx sucrose solution. The dry gel system with controlled porosity provides a novel tool for the production of tailor-made cellular-solid foods.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1046/j.1365-2621.1997.00118.x
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