Baking-drying kinetics of crisp bread: The influence of bran content and baking temperature

• Main Authors: amir یalari, mostafa Mazaheri Tehrani, seyed m.a Razavi
• Format: Article
• Language: English
• Published: Ferdowsi University of Mashhad 2015-07-01
• Series: مجله پژوهش‌های علوم و صنایع غذایی ایران
• Subjects: bran; bread; drying; modeling; diffusivity; activation energy
• Online Access: https://ifstrj.um.ac.ir/article_34500_dcc68e398307cea0e992901863ffda88.pdf
• ISSN: 1735-4161; 2228-5415

In this study, mathematical modeling of hot air baking-drying of thin-layer crisp bread was investigated. Thin-layer drying process were conducted under three different temperatures of 110, 150 and 190 °C at a constant air velocity of 0.5±0.1 m/s and absolute humidity of 0.6 ± 0.04g water/kg dry air. It was found that the baking-drying process occurred in falling rate period over the baking-drying times. Eight well-known thin-layer baking-drying models were fitted to the baking-drying experimental data of crisp bread, implementing non-linear regression analysis techniques. Based on the coefficient of determination (R²) and root mean square error (RMSE) values, it was concluded that the best models in terms of fitting performance for hot air baking-drying of bran free crisp bread were Wang & Singh and Logarithmic while for whole-wheat crisp bread were Page, Logarithmic and Wang & Singh. The moisture transfer from crisp bread was described using the Fick’s diffusion model. The effective diffusivity was within the range of 2.88×10-8 to 1.11×10-7 m2/s for bran free crisp bread and from 2.47×10-8 to 8.84×10-8 m2/s for whole-wheat crisp bread over the temperature range. The activation energy for bran free and whole-wheat crisp bread was found to be 25.22 and 23.43 kJ/mol, respectively..