Déshydratation et congélation des pommes (en anglais)

Une étude récente se penche sur un processus de congélation pour des pommes partiellement déshydratées.

Freezing foodstuffs preserves the taste and nutrients with characteristics similar to those of fresh produce. However, it often results in a soft texture and lack of retention of finished products after baking - especially in the case of fruits and vegetables - due to cell walls rupture caused by ice crystals during freezing and thawing operations. This results in a poor sensory appreciation and a poor ability to use these products in many food preparations (pastries, cooked dishes, etc.).

 

L. Ben Haj Said et al. recently published a study* on a freezing process for partially dehydrated apples (dehydrofreezing). This preservation process comprises a drying process involving air convection followed by instantaneous controlled pressure drop, resulting in decontamination and texturization, and then freezing of the finished product. The results obtained demonstrate that following freezing/thawing, a significant preservation of firmness was obtained with samples with a low water content, while firmness decreased significantly with fresh apple samples and samples with a water content higher than 200% (dry basis). Thus, partial removal of water constitutes a promising solution to prevent the negative impacts of freezing on apple fruit firmness.

 

* Ben Haj Said et al. “La congélation de pommes partiellement séchées”. Revue Générale du Froid et du conditionnement d’air (November/December 2016).