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Water sorption isotherms of freeze‐dried milk products: applicability of linear and non‐linear regression analysis in modelling
Author(s) -
Jouppila Kirsi,
Roos Yrjó H.
Publication year - 1997
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1997.tb02120.x
Subject(s) - sorption , thermodynamics , linear regression , water activity , chemistry , nonlinear regression , chromatography , regression analysis , adsorption , water content , mathematics , organic chemistry , statistics , physics , geology , geotechnical engineering
Summary Water sorption of various freeze‐dried milk products was modelled using several water sorption isotherm models, most of which proved to be applicable. Sorption models were fitted to experimental data using linear and non‐linear regression analysis. Both methods gave almost the same prediction of water sorption when the model had a good fit. The GAB model was considered to be the most applicable in predicting water sorption in practical applications, as the use of one universal model is desirable. Time‐dependent changes, e.g. lactose crystallization above glass transition, were taken into account in the water sorption modelling. Water contents and relative humidities which allowed changes in physico‐chemical properties were not included in the modelling, because of unsteady amounts of sorbed water.