Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.14/3371
Título: Accelerated life testing of frozen green beans (Phaseolus vulgaris, L.) quality loss kinetics: colour and starch
Autor: Martins, R. C.
Lopes, I. C.
Silva, C. L. M.
Palavras-chave: Accelerated life testing
Kinetics
Frozen green beans
Colour
Starch
Data: 2005
Editora: Elsevier
Citação: MARTINS, R.C. ; LOPES, I.C. ; SILVA, C.L.M. - Accelerated life testing of frozen green beans (Phaseolus Vulgaris, L.) quality loss kinetics: colour and starch. Journal of Food Engineering. ISSN 0260-8774. Vol. 67, n.º 3 (2005), p. 339–346
Resumo: This study uses the information derived from a computational research for the design of accelerated life testing (ALT) to implement experimentally the step stress methodology for the quantification of frozen green beans (Phaseolus vulgaris, L.) colour and starch degradation kinetics. Colour loss and starch degradation were successfully modelled, respectively, by a first-order reversible and apparent first-order kinetics, under dynamic temperature fluctuations. Results show that the step stress produces models with lower regression standard errors than the conventional isothermal methodology, increasing the accuracy of the estimated kinetic parameters. The ALT methodology, produces however, higher confidence intervals for the estimated kinetic parameters, than the isothermal methodology (e.g. colour b-coordinate by the: (i) isothermal methodology: k₋₁₅ ºC=22.189±0.349 day⁻¹·10⁻³; and (ii) ALT methodology: k₋₁₅ ºC=22.189±0.349 day⁻¹·10⁻³). Furthermore, as expected, higher Arrhenius activation energies (Ea) were estimated by the ALT step-stress methodology, than by the isothermal methodology (e.g. Hunter total colour difference (TCDH): (i) isothermal methodology: Ea=106.272±18.67 kJmol⁻¹; and (ii) ALT methodology: Ea=140.344±18.670 kJmol⁻¹). Accelerated tests are valuable tools, that can aid the study of quality losses in frozen foods. Although ALT tests increase the complexity of data analysis, they produce satisfactory results, when applied to frozen green beans kinetics of starch and colour losses.
URI: http://hdl.handle.net/10400.14/3371
Versão do Editor: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T8J-4CPVMNM-1&_user=2460358&_coverDate=04%2F30%2F2005&_rdoc=13&_fmt=high&_orig=browse&_origin=browse&_zone=rslt_list_item&_srch=doc-info%28%23toc%235088%232005%23999329996%23530746%23FLA%23display%23Volume%29&_cdi=5088&_sort=d&_docanchor=&_ct=19&_acct=C000057417&_version=1&_urlVersion=0&_userid=2460358&md5=cf750804d72e54424cd65016781e8a9d&searchtype=a
Aparece nas colecções:ESB - Artigos em revistas internacionais com Arbitragem / Papers in international journals with Peer-review

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