Exploring acylated anthocyanin-based extracts as a natural alternative to synthetic food dyes: Stability and application insights
Ana Rita Pereira, Virgínia Cruz Fernandes, Cristina Delerue‐Matos, Víctor de Freitas, Nuno Mateus, Joana Oliveira
Abstract
This work explores the potential of anthocyanin-based extracts (hibiscus calyxes – HC, red cabbage – RC, and butterfly pea flower − BPF) as natural alternatives to synthetic dyes in the food industry. Analyses in a pH range for food applications revealed higher color stability for the BPF extract, keeping vibrant colors over the 7 days at room temperature. At pH 3 and 100 °C, the BPF was more stable, losing half of its anthocyanin concentration after 14 h, while RC and HC lost half of their color after 7 and 2 h, respectively. The bisulfite bleaching followed a second-order reaction for HC and RC, and a first-order reaction for BPF, suggesting a minor effect of the bisulfite on this extract. Incorporating these extracts into porcine protein and agar-agar gelatin formulations produced consistent products with appealing hues, particularly the blue and purple colors for BPF and RC, dependent on the pH. • HC, RC, and BPF extracts have anthocyanins with different acylation patterns. • BPF extract presents higher color stability at a wider pH range. • Anthocyanins from BPF extract showed higher stability towards high temperature and SO 2 bleaching. • A natural blue color was obtained using BPF extract in gelatin formulations.