Natural blue and red colorants for beverage applications

Overview

This research focuses on replacing synthetic food dyes Blue #1 and Red #40 with natural colorants suitable for the beverage industry. The work targets a portfolio of natural pigments spanning yellow, red, orange, green, blue, and pink hues, with particular emphasis on developing stable blue and red alternatives. The main challenge being addressed is the inherent instability of natural pigments when exposed to light, heat, and pH variations commonly encountered in beverage production and storage.

The proposed approach leverages alternative solvents, including eutectic solvents, ionic liquids, surfactants, and biosolvents, to serve a dual purpose: extracting pigments efficiently while simultaneously stabilizing them against environmental stresses. When solvent-based stabilization is insufficient, microencapsulation strategies provide an additional layer of protection.

Technical specifications

Colorant portfolio:

• Blue pigment sourced from microalgae to replace Blue #1
• Red pigment derived from a marine bacterium to replace Red #40, offering a comparable CIELAB color space profile
• Additional anthocyanins extracted from grape pomace

Stabilization approaches:

• Hydrophilic eutectic solvents applied to extract and stabilize the blue pigment
• Bio-based hydrophobic solvents used to simultaneously extract and stabilize the red carotenoid, maintaining color integrity across different pH levels
• Microencapsulation systems employing silicon particles to enhance shelf-life when solvent stabilization alone is insufficient

Validation methods:

• Thermal stability testing at temperatures ranging from 56 to 95 degrees Celsius
• UV-light exposure assessments
• pH stability evaluations
• Absorbance and fluorescence emission analysis for long-term stability monitoring

Technology readiness level

The research is at an advanced stage, with promising results already obtained. Anthocyanin shelf-life improvements using eutectic solvents and silicon particles have been demonstrated at 55, 75, and 95 degrees Celsius. The red carotenoid extract from the marine bacterium has shown excellent half-life times at 96, 76, and 56 degrees Celsius, confirming its viability as a food-sector alternative. Future work will address raw material security, particularly for the marine bacterium source, optimize high-performance extraction solvents, and design downstream processing for both blue and red pigments.