Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Evaluation of blast freezing process on the quality of frozen strawberries (Fragaria x ananassa)
Submission Author:
Diogo Lôndero Da Silva , SC
Co-Authors:
Diogo Lôndero Da Silva, Alexsandro Santos Silveira, Christian Hermes, Adriano Francisco Ronzoni
Presenter: Diogo Lôndero Da Silva
doi://10.26678/ABCM.COBEM2021.COB2021-0384
Abstract
Domestic freezers are widely used to store food for long periods. In addition to preserving the properties of food, low temperatures inhibit the growth of microorganisms without the need for chemical additives. Freezing food with conventional domestic freezers produces large ice crystals, which in turn destroy the food cellular structure. To minimize these drawbacks, domestic blast freezers are being developed to achieve fast freezing rates in compact units. However, the relationship between the refrigeration system parameters and the food quality are not completely established. In this context, the present work is aimed at investigating the effect of the refrigeration system operating conditions on the food freezing time and quality. For this end, an experimental apparatus capable of controlling the air temperature and velocity was designed and assembled. Freezing time and drip loss were measured on strawberry samples (Fragaria x ananassa) under different air temperature and velocities. Moreover, a mathematical model was implemented to predict the freezing time. The model takes into account the food temperature variation during the phase change processes and the sensible heat removal above and below the food initial freezing point. The mathematical model was validated against the experimental results, showing errors within ±20% thresholds. The results also reveal how the operating conditions affect the balance between the convective and conductive thermal resistances, and their impacts on the freezing time. Furthermore, it is also explored how the operating conditions can be combined to improve the quality of frozen food based on drip loss measurements.
Keywords
Blast freezing, Food preservation, Drip loss, Freezing time prediction
