Influences of the Glassy and Rubbery States on the Thermal, Mechanical, and Structural Properties of Doughs and Baked Products

The technological importance of the glass transition in amorphous polymers and the characteristic temperature at which it occurs (the glass transition temperature, Tg) is well known as a key aspect of synthetic polymer science (Ferry, 1980; Rowland, 1980; Sears and Darby, 1982). Eisenberg (1984) has stated that “the glass transition is perhaps the most important single parameter which one needs to know before one can decide on the application of the many noncrystalline [synthetic] polymers that are now available.” Especially in the last several years, a growing number of food scientists have followed the compelling lead of the synthetic polymers field by increasingly recognizing the practical significance of the glass transition as a physicochemical event that can govern food processing, product properties, quality, and stability (Slade, 1984; Slade and Levine, 1984a, 1984b, 1987a, 1987b, 1988a-e; Franks, 1985a, 1985b; Blanshard, 1986, 1987, 1988; Levine and Slade, 1986, 1987, 1988a-f; Blanshard and Franks, 1987; Schenz, 1987; Slade et al., 1988; Simatos and Karel, 1988; Karel and Langer, 1988; Marsh and Blanshard, 1988).