Lapčík Lubomír, Lapčíková Barbora, Otyepková Eva, Otyepka Michal, Vlček Jakub, Buňka František, Salek Richardos Nikolaos
Department of Physical Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, 17. listopadu 12, 77146 Olomouc, Czech Republic; Tomas Bata University in Zlin, Faculty of Technology, Institute of Foodstuff Technology, nám. T.G. Masaryka 5555, 760 05 Zlín, Czech Republic.
Department of Physical Chemistry, Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, 17. listopadu 12, 77146 Olomouc, Czech Republic; Tomas Bata University in Zlin, Faculty of Technology, Institute of Foodstuff Technology, nám. T.G. Masaryka 5555, 760 05 Zlín, Czech Republic.
Food Chem. 2015 May 1;174:25-30. doi: 10.1016/j.foodchem.2014.11.017. Epub 2014 Nov 8.
Results of inverse gas chromatography adsorption/desorption experiments using selected probes on skimmed milk, whey and demineralised whey powder materials are presented. The dispersive component of surface energy was found to be dominant, indicating a low polarity character. Surface energy profiles of demineralised whey and skimmed milk showed a characteristic steep exponential decrease from approximately 170 mJ/m(2) to 60 mJ/m(2) and 140 mJ/m(2) to 45 mJ/m(2), respectively, whereas whey powder exhibited a constant (non-exponential) surface energy at approximately 45 mJ/m(2). The dispersive surface energy of demineralised whey and skimmed milk powder showed a broad distribution ranging from 40 mJ/m(2) to 120 mJ/m(2) and 175 mJ/m(2), respectively. In contrast, the dispersive surface energy distribution for whey was very narrow, ranging from only 42.8 mJ/m(2) to 45 mJ/m(2). The determined yield locus and Mohr's circles indicated that demineralised whey exhibited free flowing powder characteristics, whereas skimmed milk and whey exhibited cohesive powder flow behaviour.
