Formation of Casein-Based Triglyceride Amorphous Solid Dispersions

Restricted (Penn State Only)
- Author:
- Vyas, Megha
- Graduate Program:
- Food Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- July 18, 2024
- Committee Members:
- Federico Harte, Thesis Advisor/Co-Advisor
John Neil Coupland, Committee Member
Robert Roberts, Program Head/Chair
Ryan John Elias, Committee Member - Keywords:
- Amorphous
Dispersions
Casein
Lipids
Clean Label - Abstract:
- Amorphous solid dispersions (ASDs) occur when hydrophobic compounds prone to crystallizing are stabilized in a non-crystalline state by a solid polymer matrix. ASDs are successfully used in the pharmaceutical industry for enhancing the net solubility of hydrophobic active pharmaceutical ingredients, but little is known about their potential use in foods. In this study, palm kernel stearin (PKS) and tristearin (SSS) were used as model hydrophobic compounds to form ASDs in a casein protein matrix. Ethanol/water and temperature were used as environmental factors to disperse the lipid and protein before dehydration. First, PKS and SSS were dispersed in ethanol/water (0-100 % v/v) at 22 and 60C to determine short and long-term dispersion stability. Across all ethanol concentrations, PKS at 60C displayed the best stability, while SSS showed little dispersibility across all ethanol contents at 22oC. Then, PKS and SSS together with micellar casein were suspended in ethanol/water (0 to 60% v/v) at 22 and 60C. The solvent was removed by a two-step centrifugal vacuum evaporation followed by freeze drying (CVC) or by a single-step freeze drying (FD) to create PKS-casein and SSS-casein powders. The crystallization/melting behaviors observed by differential scanning calorimetry (DSC) and signals obtained by X-ray diffraction (XRD) were consistent with the formation of ASDs for PKS-casein powders initially formed by dispersing PKS and casein in 40-60% v/v ethanol water at 60oC and then freeze dried. SSS-casein powders showed DSC thermograms consistent with the formation of ASDs but contradictory to XRD which indicated the presence of crystallinity in all tested powders. The present study demonstrated casein-based ASDs can be successfully formed in a model system, but further research is required to understand their functionality in food systems.