A Porosimetric Mapping of Breadcrumb Structures by Differential Scanning Calorimetry and Nuclear Magnetic Resonance
Journal article, 2013

Ice crystals in frozen bread are substantially shaped by the complex pore structures of crumb. In this study we inspected the breadcrumb porosity of ice-filled pores from the profiles of ice crystals mapped by differential scanning calorimetry and nuclear magnetic resonance. Two types of wheat bread containing different amounts of dietary fiber and sugar were studied after frozen storage at -18 A degrees C for 3 weeks. Both pore sizes and pore size distributions were derived via comparing the measurements to those of water-saturated mesoporous silica (MCM-41 C18) with a well-defined pore size distribution. Good consistency was shown for the crumb pore structures obtained using the two techniques. Both bread types featured broad nanometer ranges of pore sizes characterized with largely bimodal size distributions. Besides, the frozen high-fiber bread displayed a higher proportion of large pores and a broader pore size distribution than the high-sugar bread. By comparing such pore size distributions with those obtained previously for the corresponding fresh bread, it can be concluded that structural differences between the two bread types were produced during the frozen storage, manifesting the disparate freezing performances of bread with different formulations.

Frozen bread

Cryoporometry

Nuclear magnetic resonance

Thermoporometry

Differential scanning calorimetry

Pore structures

Author

Guo Chen

Chalmers, Applied Physics, Condensed Matter Physics

SuMo Biomaterials

Åsa Östlund

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Lars Nordstierna

Chalmers, Chemical and Biological Engineering, Applied Surface Chemistry

Jan Swenson

Chalmers, Applied Physics, Condensed Matter Physics

Food Biophysics

1557-1858 (ISSN) 1557-1866 (eISSN)

Vol. 8 3 209-215

Subject Categories

Food Engineering

DOI

10.1007/s11483-013-9297-0

More information

Created

10/7/2017