| dc.contributor | Aguilera, José M. | |
| dc.contributor | Pontificia Universidad Católica de Chile | |
| dc.creator | Petzold-Maldonado, Guillermo | |
| dc.date | 2017-04-06T21:43:34Z | |
| dc.date | 2022-08-22T15:42:04Z | |
| dc.date | 2017-04-06T21:43:34Z | |
| dc.date | 2022-08-22T15:42:04Z | |
| dc.date | 2015 | |
| dc.date | 2013 | |
| dc.date.accessioned | 2023-08-21T20:46:46Z | |
| dc.date.available | 2023-08-21T20:46:46Z | |
| dc.identifier | http://creativecommons.org/licenses/by-nc-nd/3.0/cl/ | |
| dc.identifier | https://hdl.handle.net/10533/181751 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/8280286 | |
| dc.description | Ice rnorphology (size and shape) influence decisively in sensory appreciation, texture
and quality of rnany frozen foods. Ice rnorphology is also irnportant in sorne
technological processes such as freeze drying and freeze concentration, which influences
the efficiency ofthese processes. The overall objective of this thesis was to increase our
knowledge about the control on rnorphology of the ice phase in freezing food and related
processes such as freeze concentration. Freezing in food and solutions, as well as the
rnethods of observation and rneasurernent of ice rnorphology were analyzed, and the role
of ice rnorphology in sorne technological applications was discussed. Special attention
was put in the architecture or spatial arrangernent of elernents in the structure of the
frozen phase and the role in the efficiency of the freeze concentration process. When an
ice nucleus begins to grow in a solution, solutes are rejected frorn the ice phase and
accurnulate at the solid-liquid interphase, forming a hydraulic systern in the frozen
rnatrix (ice phase) with veins or channels between the ice crystals occluding the
concentrated solution. Assisted techniques (such as ultrasound or ice nucleation agents)
have proven to be irnportant in providing a rnorphology of the frozen phase that
irnproves the efficiency of freeze concentration. Other altemative are the use of externa!
driving forces such as vacuurn or centrifugation in the recovery of concentrated
solutions Propose two novel techniques (vacuurn or centrifugation) in order to use
conveniently this hydraulic systern to irnprove efficiency in the separation of solutes in
freeze concentration processes, using sucrose aqueous solutions as rnodel sarnples. By
applying vacuurn (80 kPa), the efficiency of the freeze concentration was significantly improved over atmospheric conditions showing a higher recovery of solute,
approximately 0.5 kg of sucrose obtained per 1 kg of initial sucrose compared to
recovery values ranging from 0.16 to 0.3 kg/kg for atmospheric treatments. On the other
hand, by applying centrifugation, a high recovery of solutes is achieved, reaching
approximately 0.73 kg of sucrose obtained per 1 kg of initial sucrose at 1600 relative
centrifuge force (RCF), compared to recovery 0.5 kg/kg using a less centrifuge speed
(800 RCF). The high separation efficiency of solutes using assisted techniques for freeze
concentration is a consequence of using an externa! driving force that improves the
natural separation of gravitational thawing and taking advantage of the microstructural
features of the frozen phase. W e can con elude that vacuum or centrifugation in freeze
concentration is an effective assisted technique to enhance the separation efficiency. | |
| dc.description | PFCHA-Becas | |
| dc.description | Doctor en Ciencias de la Ingeniería | |
| dc.description | 117p. | |
| dc.description | PFCHA-Becas | |
| dc.description | TERMINADA | |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.relation | instname: Conicyt | |
| dc.relation | reponame: Repositorio Digital RI2.0 | |
| dc.relation | instname: Conicyt | |
| dc.relation | reponame: Repositorio Digital RI2.0 | |
| dc.relation | handle/10533/108040 | |
| dc.relation | info:eu-repo/grantAgreement/PFCHA-Becas/RI20 | |
| dc.relation | info:eu-repo/semantics/dataset/hdl.handle.net/10533/93488 | |
| dc.rights | Atribución-NoComercial-SinDerivadas 3.0 Chile | |
| dc.rights | info:eu-repo/semantics/openAccess | |
| dc.title | Considera tións of ice morphology and driving forces in freeze concentratión | |
| dc.type | Tesis Doctorado | |
| dc.type | info:eu-repo/semantics/doctoralThesis | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | Tesis | |
| dc.coverage | Santiago | |
