CHAPTER 3 – Methodology

This chapter provides the methods that can be used to identify the physical states of various food materials that may exist in the crystalline or liquid state, combinations of both, or in their volatile form. Similarly, some foods may exist in the amorphous, crystalline, or most often in partial forms. The framework for assessment of their physical state is based on their crystallinity and molecular mobility. Crystallinity can be assessed through the microscopy (optical and electron) and X-ray diffraction methods, which are unique for all crystalline solid materials, polymers, and therefore, applicable for all food materials. Molecular mobility can be determined through spectroscopic methods (frequency range of X-ray radiation) or infrared absorption and Raman spectra. The second range of methodologies is to identify transitional temperatures with regard to the physical state. This can be done through assessment of volumetric changes, enthalpy, and mechanical and dielectric properties. Volumetric changes can be assessed as temperature changes, dilatometry, and thermal mechanical analysis; while enthalpy can be identified through calorimetric methods. Mechanical and dielectric properties can be best understood through changes of glass transition temperature and dynamic mechanical thermal analysis with mechanical spectroscopy.