Microwave and convective air on drying of Araucaria angustifolia seeds

Naiara Nobre dos Reis, Joyce Yumi Taira, Leda Battestin Quast, Ernesto Quast, Antonio Marsaioli Junior, Bruna da Silva Garais

Abstract


Microwave drying has shorter processing times compared with convection drying, which results in high-quality products and reduced energy consumption. The objective of this study is to evaluate the drying process of Araucaria angustifolia seeds using hot air at atmospheric pressure by applying microwaves (300 W and 500 W), and comparing them with the conventional drying process using hot air (80 °C). The drying time using hot air with microwaves at 500 W and 300 W was reduced by 83.33% and 73.89%, respectively, compared with conventional drying. The drying process occurred in the transient regime, with the predominance of a period of decreasing drying rate. The internal temperature of Araucaria seeds increased with the exposure time to the drying process, whereas the moisture content decreased. This tendency was greater for seeds subjected to electromagnetic fields, especially those exposed to higher power. The total phenolic compounds (TPCs) were lower by microwave drying when compared with conventional drying. The TPC loss was influenced by the internal temperature of the seed. Alternative methods to promote the increased retention of phenolic compounds during the drying process include decreasing the microwave power before the end of drying, combining traditional microwave-associated drying methods, and controlling the applied microwave power.

Keywords


Phenolic compounds; Power.;Process; Seed.

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References


Angelo, P. M., & Jorge, N. (2007). Compostos fenólicos em alimentos - uma breve revisão. Revista do Instituto Adolfo Lutz, 66(1), 1-9.

Berteli, M., Nogueira, T. L., & Marsaioli, A., Jr. (2015). Determination of the 6temperature distributions in a paddy rice bed. Brazilian Journal of Food Technology, 17(4), 319-328. doi: 10.1590/1981-6723.4814

Béttega, R., Rosa, J. G., Corrêa, R. G., & Freire, J. T. (2014). Comparison of carrot (Daucus carota) drying in microwave and in vacuum microwave. Brazilian Journal of Chemical Engineering, 31(2), 403-412. doi: 10.1590/0104-6632.20140312s00002668

Böhm, V., Kühnert, S., Rohm, H., & Scholze, G. (2006). Improving the nutritional quality of microwave-vacuum dried strawberries: A preliminary study. Food Science and Technology International, 12(1), 67-75. doi: 10.1177/1082013206062136




DOI: http://dx.doi.org/10.5433/1679-0359.2021v42n3Supl1p1487

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional