Silk fibroin–curcumin formulations for heat-stable natural food colors

Overview

This technology uses silk fibroin, a naturally occurring protein, as a molecular carrier for heat-sensitive natural colorants such as curcumin. The custom formulations bind color molecules at the molecular level, shielding them during thermal processing and preserving color intensity. This enables food and beverage manufacturers to use naturally derived colors in products that require high-heat steps, while also adding nutritional value from the silk protein.

The platform is built on documented molecular interactions between silk fibroin and curcumin. Depending on pH and reactant concentration, the resulting formulations can produce red or orange colors. The same chemistry can be extended to other color molecules to create green and brown shades, all with thermal shielding benefits.

Technical specifications

• Silk fibroin’s amphiphilic structure allows it to interact with both hydrophilic and hydrophobic color molecules, enabling stable molecular complexes.
• Preliminary laboratory experiments show that molecularly reacted silk fibroin–curcumin mixtures maintain color stability when exposed to temperatures up to 150°C.
• Red and orange colors are tunable by adjusting pH and concentration; green and brown colors can be generated using similar formulation techniques with other color molecules.
• Formulations can be customized to influence product parameters such as solubility, dispersity, color profile, texture, flavor, aroma, and mechanical properties.
• The university is equipped with instrumentation for these analyses, and silk fibroin can be scaled up for large production runs at low cost.
• Specific silk fibroin and curcumin formulations have received “no questions” responses under the FDA’s GRAS notification program for distinct food applications.

Technology readiness level

The technology is at an early stage, with laboratory-scale proof of concept complete. Molecular interactions and thermal color stability have been demonstrated in preliminary experiments. Planned next steps include systematic studies of formulation concentration and volume effects on solubility, dispersity, color, texture, flavor, aroma, and mechanical profile, followed by high-temperature extrusion trials. Color profile changes will be quantified during heating and after cooling, and final product parameters will be assessed against target specifications. Subsequent development will focus on producing brown and green colors once red and orange parameters are established.