Polyacylated anthocyanins as natural blue and red food colourant alternatives
Plant-derived polyacylated anthocyanins (PCAs) that produce stable red-to-blue colours across a range of pH conditions, offering a natural alternative to synthetic dyes such as Red #40 and Blue #1. Ten PCA isolates have been characterised with enhanced thermal, light, and oxygen stability, with copigment screening underway to further tune colour performance.
Overview
This solution offers a portfolio of polyacylated anthocyanins (PCAs) isolated from plant floral tissue as natural colourants capable of producing hues ranging from red to blue. The technology targets the growing demand for replacements for synthetic food dyes such as Allura Red (Red #40), Indigo Carmine (FD&C Blue 2), and Brilliant Blue (Blue #1). Unlike conventional anthocyanins, which typically require near-neutral pH to display blue colouration, these PCAs begin to shift towards blue at pH 4 and remain stable without the addition of metals. The result is a natural pigment platform with improved colour range, pH flexibility, and shelf-life stability suited to food, beverage, cosmetic, and nutraceutical applications.
Technical specifications
Key features:
- Ten PCA isolates obtained from plant floral tissue and characterised by UV-VIS spectroscopy
- Colours closely matching Red #40, FD&C Blue 2, and Blue #1 achievable through pH adjustment
- Enhanced thermal, light, and oxygen stability compared with non-decorated anthocyanins and other PCAs
- No metal additives required for colour stabilisation
- Molecular stacking over the anthocyanin chromophore increases stability of the coloured species
- Copigments can be introduced to modulate colour and reduce pH dependency
- Molecular dynamics simulations (Gromacs, B3LYP 6-31G* optimised geometries, TIP3P water model, 500 ns) suggest a stacking arrangement that leaves one chromophore plane exposed, enabling further molecular interactions
- High-throughput microplate-based UV-VIS assay planned for screening copigment combinations, with colour calculated using in-house software
- Quantum and molecular dynamics modelling planned to identify pigment–copigment interaction sites
Technology readiness level
The PCAs have been isolated and their optical and stability properties validated through buffer-based UV-VIS testing across pH 1 to pH 8 over 15 days, with colour values converted to CIE lab colour space. Stability and colour intensity have been shown to increase with the number of molecular decorations on the anthocyanin. Computational modelling has provided initial insight into stacking geometry. The next phase involves high-throughput copigment screening and molecular dynamics validation to refine colour performance and broaden application readiness.
About John Innes Centre
John Innes Centre is an independent UK research institute in Norwich focused on plant and microbial science and operating as a registered charity. Embedded within the Norwich Research Park, it offers industry access to co‑located laboratories, extensive glasshouses and controlled‑environment rooms, a dedicated field experimentation farm, and shared research platforms available to external users. A Knowledge Exchange and Commercialisation team brokers partnerships, while IP and licensing are channelled via Plant Bioscience Limited, jointly owned with The Sainsbury Laboratory and BBSRC. Research is strategically supported by UKRI‑BBSRC with additional competitive awards from BBSRC and NERC. The park ecosystem links partners to the University of East Anglia, a major NHS hospital, and allied institutes for streamlined collaboration.
delivered to your inbox.