Engineered yeast producing blue indigoidine pigment for sustainable food coloration

Overview

This solution leverages an engineered non-conventional food yeast to produce indigoidine, an intense blue pigment with demonstrated antimicrobial and antioxidant activities. The bioprocess offers a sustainable alternative to synthetic blue colorants, which face increasing regulatory and consumer scrutiny in food and beverage applications. Production has been validated at gram-per-liter scale using inexpensive, locally sourced feedstocks including lignocellulosic hydrolysates and waste cooking oil, supporting cost-effective manufacturing. The underlying yeast and its products have received GRAS (Generally Recognized as Safe) status from the FDA, which is expected to streamline regulatory approval for the pigment. Additional yeast strains producing yellow, orange, and red pigments are also available, enabling a full spectrum of natural color solutions for food and beverage applications.

Technical specifications

Key features:

• Organism: Non-conventional food-grade yeast engineered for indigoidine biosynthesis
• Production scale: Gram-per-liter pigment titres achieved in bioreactor fermentation
• Feedstock flexibility: Utilizes cheap, sustainable carbon sources including lignocellulosic hydrolysates and waste cooking oil
• Process optimization: Validated across varied carbon and nitrogen sources, aeration rates, carbon-to-nitrogen ratios, and intracellular precursor supplementation
• Pigment stability: Retains colour after heating to 96°C for 2 minutes (12% loss at 5 minutes), stable at pH 2.7, under direct and ambient light exposure, and during cold storage at 4°C for weeks
• Functional properties: Indigoidine exhibits antimicrobial and antioxidant activities in addition to coloration
• Regulatory status: Production yeast and its products have GRAS designation from the FDA
• Colour palette extension: Additional engineered strains available for yellow, orange, and red pigments

Technology readiness level

The technology has been validated at laboratory and bioreactor scale, with demonstrated production titres in the gram-per-liter range. Pigment stability has been confirmed under conditions relevant to food and beverage processing, including thermal exposure, acidic pH, light exposure, and cold storage. Ongoing work aims to increase indigoidine titres through genetic and process engineering of the production strain, and to assess long-term stability to meet commercial shelf-life requirements. A planned collaboration is intended to evaluate commercial potential, regulatory pathways, and safety assessments. Organising tasting panels to evaluate sensory impact on beverages is also planned. The technology is positioned at TRL 4–5, with demonstrated feasibility at relevant scale and active development toward commercial readiness.