Soaking treatments to improve frozen food quality and stability

[Departement_IRSTEA]EAA [TR1_IRSTEA]EAA5-FRIGEQUAL, Maîtrise des procédés frigorifiques et de la chaîne du froid alimentaireSoaking pretreatments in concentrated solutions (Immersion Chilling and Freezing, Osmotic Dehydration) can be used to improve frozen food quality and stability. ICF is generally used to achieve quick freezing prior to storage in conventional cold rooms. The main difficulty is related to solute entrance, which may not be desired. Recent results obtained on apple cylinder are presented, which clearly show that further control of solute entrance in freezing conditions could be achieved through food surface treatments, including: precoating with cold water before ICF; use of a complex immersion solution containing high molecular weight solute; quick freezing of the outer food layers. Osmotic dehydration is generally used to achieve partial dewatering and direct formulation of the food item, prior to conventional air blast freezing, or ICF. Storage behaviour (0-3 months) of pretreated or non pretreated apple cubes are compared in terms of colour evolution and exsudate loss after thawing