Rheological characterization of triglyceride shortenings

Abstract

The rheological properties of shortenings with similar physicochemical characteristics but diverse functionality were investigated under small and large oscillatory shear. Particular attention was drawn to the mechanical behavior of roll-in shortenings, characterized for resisting work softening and forming continuous fat thin films during dough lamination and sheeting. All shortenings displayed low-frequency dependence, reminiscent of viscoelastic solids where the storage modulus is higher than the loss modulus, and displayed a comparable linear envelope, encompassing relatively small shear strains, such as those encountered in other fat systems. Linear elastic moduli and yield stress, previously used to designate roll-in functionality, remained unremarkable. In contrast, nonlinear viscoelastic behavior of roll-in shortenings differed considerably from all-purpose commercial shortenings. Lissajous-Bowditch curves suggested less local intracycle strain stiffening and less average intercycle strain softening for roll-in shortenings than other shortenings. Likewise, their Fourier spectra indicated a gradual evolution of the third harmonic into the nonlinear regime characterized by higher slopes. The third and fifth harmonics grew monotonically, and the third overtone leveled off and showed no stress decays unlike other samples, suggesting a marked ability of roll-in shortenings to withstand deformation at high stresses. Conversely, the dissipative energy scaled in a similar fashion for all shortenings. Moreover, roll-in shortenings displayed enhanced thixotropic behavior supported by lower power law indexes and prompt structural rebuilding after steady shear cessation. Overall, these rheological signatures facilitated the differentiation among the utilization of shortenings and correlated well with the functionality of roll-in shortenings.

Zero‐Trans Cake Shortening: Formulation and Characterization of Physicochemical, Rheological, and Textural Properties

“…CM101 had the highest G ′ and G ″ over the frequency range, which could be related to its SFA content and SFC ( P < 0.05). This was in line with Macias‐Rodriguez and Marangoni () results of analyzing the rheological characterization of triglyceride shortenings. They showed that shortenings with higher saturated fats had a higher G ′.…”

Oleogel Fabrication Based on Sodium Caseinate, Hydroxypropyl Methylcellulose, and Beeswax: Effect of Concentration, Oleogelation Method, and Their Optimization

“…, in all oleogels and commercial shortening, both G ′ and G ″ slightly enhanced parallel with enhancing frequency in which G′ value predominated over the whole frequency range, demonstrating the gel‐like characteristic of these systems. A similar trend was also observed for oleogels of carnauba wax (CRW) and candelilla wax (CDW) as a shortening replacer as well as for some commercial shortening in previous studies (Macias‐Rodriguez and Marangoni, ; Mert and Demirkesen, ). The Bohlin model with R 2 of 0.96 fitted the dependency of G ′ on frequency (data not shown).…”

Understanding the functionality of lipid‐based materials under large‐amplitude nonlinear deformations

“…Since we observed that multiple formulations (e.g. palm‐oil based, soybean‐oil based, trans ‐containing, trans ‐free) achieved the same rheological criteria, the structure‐function framework seemed to dictate the unique laminating performance .…”

“…The remaining question then arises: what rheological characteristics a shortening must meet to achieve the special laminating functionality? To address this, we present LAOS results, which are related to the macroscopic functionality of laminating shortenings [4,5]. Figure 1a shows strain softening as the strain amplitude is increased; however, the response is otherwise unremarkable, that is both shortenings behave as soft elastic solids (G' > G").…”

“…Since we observed that multiple formulations (e.g. palm-oil based, soybean-oil based, transcontaining, trans-free) achieved the same rheological criteria, the structure-function framework seemed to dictate the unique laminating performance [4,5]. Finally, for edible fats structured with high solid fat content, it makes the most sense that viscous contributions (which account for the plasticity of the crystal network in addition to the viscosity of the liquid-oil) have the largest impact in functionality.…”