Determinación experimental y predicción matemática del tiempo de congelación de atún (Thunnus albacares) y brócoli (Brassica oleracea var. italica)

Abstract

Food preservation, transportation and storage are key factors in ensuring the quality of the final product. In this context, the correct application of freezing processes represents an important challenge. The construction of freezing curves allows the study of the thermal behaviour of food matrices, which facilitates the determination of optimal freezing temperatures and times to obtain high quality products. In the present investigation, an IQF fluidized bed tunnel was used to freeze samples of tuna (Thunnus albacares) and broccoli (Brassica oleracea var. italica) until a temperature of minus 10 degrees Celsius was reached at the thermal centre of each sample, considered the optimum freezing temperature. Through a series of experimental trials, the freezing time was determined, and these results were compared with the times estimated by mathematical models. The results showed that the experimental freezing time was longer than the theoretically calculated one. It was also found that the direction of air flow significantly influences the process. When the samples were exposed to a vertical upward (bottom-up) air flow, the freezing time was reduced by approximately 15 minutes compared to horizontal air flow.