Dynamic Mechanical Analysis as a Complementary Technique for Stickiness Determination in Model Whey Protein Powders

Abstract

The α-relaxation temperatures (Tα), derived from the storage and loss moduli using dynamic mechanical analysis (DMA), were compared to methods for stickiness and glass transition determination for a selection of model whey protein concentrate (WPC) powders with varying protein contents. Glass transition temperatures (Tg) were determined using differential scanning calorimetry (DSC), and stickiness behavior was characterized using a fluidization technique. For the lower protein powders (WPC 20 and 35), the mechanical Tα determined from the storage modulus of the DMA (Tα onset) were in good agreement with the fluidization results, whereas for higher protein powders (WPC 50 and 65), the fluidization results compared better to the loss modulus results of the DMA (Tα peak). This study demonstrates that DMA has the potential to be a useful technique to complement stickiness characterization of dairy powders by providing an increased understanding of the mechanisms of stickiness.

The Effect of High Protein Powder Structure on Hydration, Glass Transition, Water Sorption, and Thermomechanical Properties

“…Structural α-relaxation is the large-scale molecular reorganization of a material and occurs in amorphous systems at temperatures ~20-30 • C above the onset to the calorimetric T g . This process decreases the structural relaxation time down to 10 −14 s [41,42].…”

The moisture plasticizing effect on enzyme-catalyzed reactions in model and real systems in view of legume ageing and their hard to cook development

“…Since the study focuses on biochemical stability, glass transition determination based on molecular mobility or mechanical changes (Dynamic Mechanical Thermal Analysis) is the practical choice. DMTA is able to detect short range motion prior to the glass-liquid transition and hence is more sensitive than DSC for the determination of Tg (Abiad et al, 2010;Hutchinson, 2009;O'Donoghue et al, 2020). A previous study (Chigwedere et al, 2019) reporting the cooking properties with the glass transition concept of stability has employed Thermal Mechanical Compression testing (TMCT) as the Tg determination method.…”

Physicochemical Properties and Structure Changes of Food Products during Processing

“…The study of O’Donoghue et al [ 12 ] studied the α-relaxation temperatures, derived from the storage and loss moduli using dynamic mechanical analysis, which were compared to methods for stickiness and glass transition determination for a selection of model whey protein concentrate powders with varying protein contents.…”