Monitoring of Weight Losses in Meat Products during Freezing and Frozen Storage

Abstract

During freezing and frozen storage, the surface of unpackaged food is exposed to mass transfer exchange with the environment. Ice sublimes forming a dry, porous layer altering the sensory characteristics of the foods. This work describes the design and use of an experimental equipment with controlled operating conditions to quantify weight losses during refrigeration, freezing and frozen storage. Experiments were carried out with several meat products (hamburgers, meat balls, beef cylinders and chicken slabs) under different air conditions: temperature (- 40 to - 20°C), relative humidity (50—95%) and air velocity (1—5 m/s). Weight loss occurred during freezing ranged between 0.28 and 2.98%, meanwhile the global values corresponding to both stages (freezing plus storage up to reach 1200 min of refrigeration) ranged between 1.67 and 6.15%. Good agreement was found between experimental data for the different products tested and data from a numerical model developed in previous work. The results demonstrated that surface dehydration degree should be regarded as an important quality parameter to take into account and to quantify.