chapter  3
34 Pages

Moisture and Water Activity

ByYOUNG W. PARK

Contents 3.1 Introduction ..................................................................................................................... 36 3.2 Properties of Water in a Food System ............................................................................... 37 3.3 Water in Meat and Other Foods ...................................................................................... 38 3.4 Water Activity .................................................................................................................. 38 3.5 Mechanism of Drying Related to Moisture Determination ...............................................41 3.6 Sampling Methods for Moisture Determination .............................................................. 42 3.7 Methodologies of Moisture Determination ...................................................................... 43

3.7.1 Direct Methods .....................................................................................................45 3.7.1.1 Air-Oven Drying ....................................................................................45 3.7.1.2 Vacuum-Oven Drying ............................................................................51 3.7.1.3 Freeze-Drying .........................................................................................53 3.7.1.4 Distillation Methods ...............................................................................53 3.7.1.5 Karl Fischer Titration Method ............................................................... 56 3.7.1.6 Chemical Desiccation ............................................................................ 58 3.7.1.7 Th ermogravimetric Method ................................................................... 58 3.7.1.8 Gas Chromatography ............................................................................. 58 3.7.1.9 Application of Direct Methods in Moisture Determination ....................59