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Glass Transition Behavior and Rheological Properties of Surfactants and Gluten‐Surfactant Mixtures
Author(s) -
Toufeili Imad,
Kokini Jozef L.
Publication year - 2004
Publication title -
cereal chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.558
H-Index - 100
eISSN - 1943-3638
pISSN - 0009-0352
DOI - 10.1094/cchem.2004.81.5.582
Subject(s) - chemistry , differential scanning calorimetry , gluten , glass transition , pulmonary surfactant , rheology , endothermic process , chemical engineering , nuclear chemistry , organic chemistry , food science , thermodynamics , polymer , materials science , adsorption , composite material , biochemistry , physics , engineering
Diacetyltartaric acid esters of monoglycerides (DATEM) and sodium stearoyl lactylate (SSL) displayed thermal events corresponding to glass transition temperature ( T g ) and melting of crystalline domains, while monoglycerides (MG) exhibited an endothermic peak corresponding to melting of crystalline structures when heated in a differential scanning calorimeter. The plasticizing effect of water on T g of gluten exhibited little apparent change in the presence of DATEM, MG, or SSL (glutensurfactant 10:1), in the moisture range of 6.5–21.3% as shown by mechanical spectrometry and differential scanning calorimetry. Glutensurfactant mixtures showed higher G ′ and apart from gluten‐SSL, which displayed higher tan δ ( G ″/ G ′) at ≤2.51 rad/sec, lower tan δ values than gluten in the frequency range of 0.1–100 rad/sec. DATEM and SSL softened the gluten network before cross‐linking reactions, while MG shifted the onset of cross‐linking reactions to higher temperatures at moisture contents of 30–40%. Complete vitrification of the gluten network occurred at higher temperatures, at the indicated moisture contents, in the presence of surfactants. Softening of the matrix and the delay in cross‐linking of gluten, in the presence of surfactants, might allow for greater expansion of doughs during baking with concomitant increase in loaf volumes.