Convective drying of Roselle calyx: kinetics and drying rate

• Autor(a) principal: Paiva, Mateus Vinicius de
• Data de Publicação: 2021
• Outros Autores: Sanches, Marcelo Zuchi, Chies, Leonardo Galice, Vieira, Admilson Lopes, Nicoleti, Joel Fernando, Sakanaka, Lyssa Setsuko
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Research, Society and Development
• Texto Completo: https://rsdjournal.org/index.php/rsd/article/view/12224
• topic: Hibiscus sabdariffa; Mathematical model; Equilibrium humidity.; Hibiscus sabdariffa; Modelagem matemática; Umidade de equilíbrio.; Hibiscus sabdariffa; Modelaje matemática; Humedad del equilíbrio.

Roselle calyx is rich in malic acid, anthocyanins, ascorbic acid, calcium and iron, which make it an interesting ingredient, dried or as an extract powder, to functional foods that helps promote health, physical and mental well-being. Drying is a unit operation that adds practicality to the consumption of a great variety of foods, also having the advantage of concentrating the active compounds due to the removal of moisture from the material, extending its shelf life, without the need of refrigeration, by the reduction of water activity. The study of drying kinetics provides important information for the project and design of dryers, as well as for the processes modeling and simulation. Therefore, the objective of this work was to evaluate the kinetics of convective drying of Roselle calyces using a convective forced air oven. Roselle calyces were placed in trays and dried at temperatures of 50, 60 and 70 oC until constant weight. Samples humidity and water activity were determined. Five models were used to fit drying curves using Microsoft Excel program. Page’s model showed to be the best to describe the drying kinetics of Roselle calyces and statistics data. Only the decreasing drying rate was observed, with a high rate at the beginning of the drying, being gradually reduced until the end of the process.