|
4E - Food Safety (WEP/204) Modelling temperature fluctuations in food cold storage to prevent toxicity risk. Pitarma, Rui A.1, Ferreira, Maria E.1, Carvalho, Maria G.2, 1 Polythecnic Institute of Guarda - ESTG, Guarda, Portugal, Portugal2 Technical University of Lisbon, Lisbon, Portugal, Portugal ABSTRACT- Over the past decade the cold chain has grown through an increasing awareness on the part of the consumer to the effect of temperature on food quality. The quality and nutritional value of food products stored in cold state are affected by the time, the temperature, the air speed and relative humidity of the storage period. Large temperature fluctuations during storage, transportation and handling can accelerate deteriorative and toxic effects. In this context, the transportation of perishables in insulated refrigerated trucks, trailers, and containers continues to represent the most delicate problem, once that the range of temperature fluctuations involved can be relatively large. In fact, experimental results in refrigerated long road vehicles show temperature differences in the cargo up to 12 °C. Inadequate air circulation within the truck chamber it is aimed as the major cause of improper cargo refrigeration. A knowledge of temperature history and temperature profiles of refrigerated food subjected to fluctuating environmental conditions is necessary for the design of cold storage and transportation systems to prevent food toxicity risk. This paper presents a computational model to predict and to visualize the velocity, the temperature and relative humidity fields in refrigerated chambers. The computational model consists on a numerical procedure, which solves the three-dimensional flow equations and the energy equation for a large number of nodal points in refrigerated room. The computer model was validated by experimental results. The model was applied to calculate and to visualize the cold quality provided by a refrigerated truck chamber. A case study of long road transport under strong solar radiation was also considered. Key words: Food toxicity, Food storage, Refrigeration, Numerical simulation |
