Print Email Facebook Twitter Water uptake mechanism in crispy bread crust Title Water uptake mechanism in crispy bread crust Author van Nieuwenhuijzen, N.H. Meinders, M.B.J. Tromp, R.H. Hamer, R.J. van Vliet, T. TNO Kwaliteit van Leven KvL Publication year 2008 Abstract Crispness is an important quality characteristic of dry solid food products such as crispy rolls. Its retention is directly related to the kinetics of water uptake by the crust. In this study, a method for the evaluation of the water sorption kinetics in bread crust is proposed. Two different sorption experiments were used: an oscillatory sorption test and a sorption test in which the air relative humidity (RH) was increased stepwise. These two experiments had different time scales, which made it possible to get a better understanding of the mechanisms involved. Results show that the adsorption and desorption dynamics of the oscillatory sorption test could be described by a single exponential in time. The water uptake rate (k) was one of the fitting parameters. A maximum in the water uptake rate was found for a RH value between 50 and 70%. The rate parameters of the experiment where RH was increased stepwise were around a factor 10 lower tharj those derived from oscillatory sorption experiments. This is an important factor when designing experiments for the determination of water uptake rates. In addition, also a parameter describing the time dependence of the rate parameters of the oscillatory sorption experiment was calculated (C), again by fitting a single exponential to the rate parameters. C was in the same range as the rate parameter of the isotherm experiment. This indicates that different (relaxation) processes are acting at the same time in the bread crust during water uptake. © 2008 American Chemical Society. Subject NutritionFood technologywateradsorptionarticlebreadchemistrycomparative studyhumiditykineticsphysical chemistrysensationAdsorptionBreadChemistry, PhysicalHumidityKineticsSensationWater To reference this document use: http://resolver.tudelft.nl/uuid:36f4ce0e-51f8-49f1-afec-33138794b6f1 DOI https://doi.org/10.1021/jf800537b TNO identifier 240953 ISSN 0021-8561 Source Journal of Agricultural and Food Chemistry, 56 (15), 6439-6446 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.