Rheological Behavior and Structural Evolution of Capillary Suspensions in Food Systems: Droplet Deformation...

Area of Science:

• Food Science and Technology
• Colloid and Surface Science
• Rheology

Background:

• Solid fats are crucial for food texture and sensory properties.
• High saturated fatty acids (SFA) and trans fatty acids (TFA) in solid fats necessitate healthier alternatives.
• Developing functional, healthier lipid systems is an ongoing challenge.

Purpose of the Study:

• To explore capillary suspension structuring for transforming liquid oils into plastic fats.
• To investigate the impact of formulation variables on structural and rheological properties.
• To develop a predictive model for fluid-gel transitions in these systems.

Main Methods:

• Systematic variation of octenyl succinate starch (OSA-starch) particle concentration, primary oil, and secondary liquid proportions.
• Rheological analysis to measure yield stress and characterize yielding behavior.
• Stepwise regression analysis to develop an empirical predictor for fluid-gel transition.

Main Results:

• Capillary suspension structuring successfully transformed liquid oils into plastic fats.
• Rheological analysis showed significant formulation-dependent yield stress and a consistent two-step yielding.
• An empirical predictor for fluid-gel transition was developed with R² > 0.98.

Conclusions:

• The study provides mechanistic insights into fluid-gel transitions in capillary suspensions.
• A "liquid-bridge stretching" hypothesis explains the observed yielding behavior.
• Capillary suspensions offer a promising route to healthier, tunable lipid systems for food applications.