Resumo

ARIAS-GIRALDO, Sebastián; CEBALLOS-PENALOZA, Adela M.  e  GUTIERREZ-MOSQUERA, Luis F.. Parameters for açaí pulp freezing. TecnoL. [online]. 2019, vol.22, n.46, pp.29-42. ISSN 0123-7799.  https://doi.org/10.22430/22565337.1117.

Refrigeration and freezing have been traditionally used in food preservation. In the industry of açaí, a Brazilian fruit, they are the most common technologies. The application of theoretical models for predicting freezing times and temperatures allows an effective control of those operations. The objective of this work was to evaluate the time, temperature, and speed of two processes, conventional and cryogenic freezing, for açaí pulp. The conventional freezing time for said product was 153.68 ± 6.42 min, with a minimal error with respect to Pham’s (0.54 %) and Nagaoka’s (1.71 %) equations. The fast freezing time, in turn, was 100.56 ± 17.90 s (1.68 ± 0.29 min), which is efficiently represented by Nagaoka’s equation (6,81 %). The initial freezing temperatures for the slow and fast modes were -0.64 ± 0.02 °C and -2.91 ± 0.86 °C, respectively. Based on these results, correlations can be obtained and validated to effectively predict the freezing times of fresh açaí pulp considering the main parameters in the process: geometry, cold medium temperature, and food composition.

Palavras-chave : Açaí; cryogenic freezing; Euterpe oleracea; food engineering.

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