Effect of hot air temperature on mechanical properties of dried apples

• Published in: Journal of food engineering Vol. 64; no. 3; pp. 307 - 314
• Main Authors: Lewicki, Piotr P., Jakubczyk, Ewa
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2004; Elsevier
• Subjects: air drying; Apple; apples; Biological and medical sciences; compression stress; Convection drying; dried fruit; drying quality; drying temperature; Food engineering; Food industries; food storage; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; General aspects; Mechanical properties; mechanical stress; Shrinkage; storage quality; stress relaxation; texture; water content; Mechanical properties; Apple; Shrinkage; Convection drying; Fruit; Air temperature; Temperature effect
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2003.10.014

The aim of this work was to determine the effect of temperature and water content on the mechanical properties of convection dried apples. Apples v. Idared were cut into slices and then air-dried at temperature in the range from 50 to 80 °C. Mechanical properties were measured by compression–relaxation test. Samples were investigated after drying and also after 5 weeks of storage over anhydrous calcium chloride at constant temperature. Analysis showed that the observed differences between compression–relaxation curves of apples dried at 50, 60 and 70 °C were not significant. Decreasing of water content caused an increase of force needed to compress dried apples. Drying at 80 °C affected the texture of dried apples much more in comparison to those obtained at lower hot air temperature. The use of suitable temperature and drying of apples to definite water content could be used to design the mechanical properties of the final product.