De nombreux programmes sont dédiés à la recherche d'une alternative naturelle au FD&C Blue No.1, recherche difficile vu la rareté du bleu cyan dans la nature. Des études antérieures ont montré que les anthocyanes de chou rouge produisent une couleur bleue vibrante en solution (pH neutre) trop violette pour remplacer le colorant bleu artificiel mais une anthocyanine mono-acylée mineure, contribuant à moins de 5% de la teneur totale en anthocyanes du chou rouge, a été révélée (pic 2, P2).

Les travaux de Denish et al. explorant plus avant le potentiel de ces anthocyanes de choux ont été publié dans la revue Sciences Advances d'avril 2021. Les auteurs notent que des études de toxicité seront nécessaires pour définir les limites d'utilisation du nouveau colorant et les précautions de sécurité alimentaire, et des recherches supplémentaires seront nécessaires pour évaluer sa stabilité et sa couleur dans un large éventail d'applications.

L'illustration issue de l'article de Denish et al. sur les anthocyanes du choux rouge a été choisie pour la couverture du numéro d'avril 2021 de Science Advances.

Référence de l'article :

Pamela R. Denish, Julie-Anne Fenger, Randall Powers, Gregory T. Sigurdson, Luca Grisanti, Kathryn G. Guggenheim, Sara Laporte, Julia Li, Tadao Kondo, Alessandra Magistrato, Mícheál P. Moloney, Mary Riley, Mariami Rusishvili, Neda Ahmadiani, Stefano Baroni, Olivier Dangles, Monica Giusti, Thomas M. Collins, John Didzbalis, Kumi Yoshida, Justin B. Siegel1 and Rebecca J. Robbins (2021) Discovery of a natural cyan blue: A unique food-sourced anthocyanin could replace synthetic brilliant bluesynthetic brilliant blue, Science Advances, 7 (15), eabe7871

DOI: 10.1126/sciadv.abe7871

ONLINE COVER: Several research programs around the world are dedicated to the hunt for a natural alternative to FD&C Blue No.1—a challenging effort given that cyan blue is one of the rarest colors in nature. While previous research has shown that red cabbage anthocyanins produce a vibrant blue color in a pH-neutral solution, this color has been too violet to replace artificial blue dye. Studies have further found that Peak 2 (P2), a minor mono-acylated anthocyanin, warrants further investigation, yet this compound contributes less than 5% of red cabbage's total anthocyanin content. To further explore the potential of anthocyanins as a blue colorant, Denish et al. incubated P2, as well as anthocyanins P5 and P8, with aluminum cations, finding that only the P2 solution produced the desired blue color. Next, the researchers tested the color stability of blue colorant developed from P2, observing that while many naturally sourced colorants have limited stability over time, its color only diminished by 14% in sugar syrup over 55 days.

Finally, Denish et al. identified a hydrolytic enzyme that converts the red cabbage anthocyanins P6, P7, and P8 into P2, addressing the need to obtain sufficient quantities of P2 to develop a food coloring agent. The authors note that toxicity studies will be needed to define the novel colorant's usage limitations and food safety precautions, and further research will be required to evaluate its stability and color in a wide range of applications.

[CREDIT: ANILAKKUS/ISTOCK]