Earth Brown: naturally thermostable melanin-based food color

Overview

Earth Brown is a natural brown pigment produced by thermophilic methane-oxidizing bacteria via fermentation. It is a secreted, nitrogen-containing aromatic polymer with eumelanin-like characteristics, delivering naturally occurring brown-to-dark-brown shades. Unlike many synthetic fermentation routes, Earth Brown is produced using a simple medium and inexpensive gas feedstock, and the secreted pigment can be efficiently separated from the fermentation broth. The pigment is offered in dry, aqueous-dispersible, and lipid-dispersible formats, enabling use across a range of food matrices and product types. Co-produced microbial exopolymeric substances (EPS), similar in function to alginate, enhance dispersion and can provide thickening, stabilization, or binding benefits in formulations. The product is currently commercialized for skincare applications and is being advanced for food use.

Technical specifications

Production and processing:

• Fermentation platform demonstrated at laboratory and pilot scales
• Productivity of approximately 0.15 kg/h
• Secreted pigment enables efficient separation, recovery, and processability
• Simple medium with low-cost gas feedstock reduces dependence on costly tyrosine precursors

Product features:

• Eumelanin-like nitrogen-containing aromatic polymer
• Brown to dark-brown shades with antioxidant functionality from radical-bearing structure
• Co-produced EPS supports dispersion, thickening, stabilization, and binding
• Available in dry, aqueous, and lipid-dispersible formats

Intended food applications:

• Natural food colorant for brown-to-dark-brown shades
• Potential co-formulation benefits in matrices where thickening or stabilization is needed
• Suited for thermal processing workflows; process-stability studies are part of the next validation phase

Technology readiness level

The fermentation and production platform has been evaluated at laboratory and pilot scale, with a measured productivity of about 0.15 kg/h. Earth Brown is already commercialized for skincare applications, demonstrating a mature production route for non-food use. For food applications, the next validation phase includes defining the food-grade ingredient, confirming production consistency at scale, optimizing pigment recovery and particle-size control, generating color performance data across formulations, testing food-matrix compatibility, and evaluating process and storage stability (including extrusion trials at 100–150°C and 12-month ambient storage). A safety and regulatory package covering compositional identity, toxicology, genotoxicity, digestibility, allergenicity, contaminants, and manufacturing controls is also planned. This positions Earth Brown as a near-commercial natural colorant for food partners seeking a sustainable, scalable brown pigment.