Partager

Document IIF

Effets combinés du blanchiment et de la congélation sur la structure cellulaire, de la texture et de la couleur des haricots verts.

Combined effects of blanching and freezing on the cellular structure, texture and colour of green beans.

Auteurs : AMARANTE A., PERUSSELLO C., LANOISELLÉ J. L.

Résumé

This work studies the combined effects of blanching, using either peroxydase or lipoxygenase as indicators, and different freezing conditions on the final quality of green beans. The time-temperature blanching conditions for the freezing experiments were chosen arbitrarily to reach an indicator residual activity of 10%. The blanching temperatures used were 70, 80, 90 and 100°C. After blanching, the samples were submitted to four freezing conditions: a) nitrogen vapour; b) blast freezing, c) natural convection, and d) natural convection inside polystyrene boxes. The freezing rate was measured by means of thermocouples placed in the center of the green beans pods and by fluxmeters adhered to their surfaces. The quality of thawed samples was evaluated by: a) light microscopy of thin cut transversal sections of the pods; b) axial compression tests by application of constant constraint of 2 N and; c) evaluation of color variation using the CIELAB colour space. HTST blanching protocols contributed to minimize color and texture deterioration. High freezing rates [higher than -94.2 kJ/(kg.min)] enabled preservation of the internal parenchyma and, consequently the retention of firmness. Colour is not significantly affected by the freezing rate.

Documents disponibles

Format PDF

Pages : ICR07-C2-728

Disponible

  • Prix public

    20 €

  • Prix membre*

    Gratuit

* meilleur tarif applicable selon le type d'adhésion (voir le détail des avantages des adhésions individuelles et collectives)

Détails

  • Titre original : Combined effects of blanching and freezing on the cellular structure, texture and colour of green beans.
  • Identifiant de la fiche : 2008-0284
  • Langues : Anglais
  • Source : ICR 2007. Refrigeration Creates the Future. Proceedings of the 22nd IIR International Congress of Refrigeration.
  • Date d'édition : 21/08/2007

Liens


Voir d'autres communications du même compte rendu (839)
Voir le compte rendu de la conférence

Indexation