Ethanol pre-treatment improves vegetable drying and rehydration: Kinetics, mechanisms and impact on viscoelastic properties

Autor(es)

Rojas, Meliza Lindsay ^[1] ; Augusto, Pedro E. D. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Agri Food Ind Food & Nutr IAN, Luiz de Queiroz Coll Agr ESALQ, Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Food Engineering; v. 233, p. 17-27, SEP 2018.
• Citações Web of Science: 12

Resumo

Drying is a complex unit operation widely applied in food processing. There is still an increasing interest to enhance the process, as well as the product quality and properties. In this work, ethanol was used to enhance drying of pumpkin, which has been considered as a structurally representative material of plant foods. The effect of ethanol treatment on microstructure, convective drying kinetics (Page model), rehydration kinetics (Peleg model) and viscoelastic properties (generalized Maxwell model) was evaluated. The pre-treatment was conducted by immersing pumpkin cylinders in ethanol before convective drying. The ethanol treatment accelerated both drying and rehydration processes. Microstructure modifications were observed after the ethanol treatment, drying and rehydration. The rehydrated samples (control and ethanol treated) showed different viscoelastic properties compared with those in natura, which presented low stress decay and more residual elasticity. A possible mechanism was proposed. In conclusion, the ethanol improved both drying and rehydration processes, without negatively impacting on the microstructure and viscoelastic properties of pumpkin cylinders. (C) 2018 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 16/18052-5 - +Pro²FOOD: tecnologias emergentes para melhoria de processos e propriedades de alimentos
• Beneficiário: Pedro Esteves Duarte Augusto
• Modalidade de apoio: Auxílio à Pesquisa - Regular