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Updated: Oct 19, 2025

Isolation and Characterization of Intact Phycobilisome in Cyanobacteria
Published on: November 10, 2021
The formation of phycocyanin-EGCG complex for improving the color protection stability exposing to light
Rui Yang1, Tianhua Ma1, Lina Shi1
1State Key Laboratory of Food Nutrition and Safety, College of Food Science and Technology, Tianjin University of Science & Technology, Tianjin 300457, China.
Abstract:
Phycocyanin (PC) is a natural pigment-protein complex in food dye applications. In this study, a phycocyanin-epigallocatechin gallate (EGCG) complex (PE) was prepared and the effects of EGCG on the structure and color stability of PC were evaluated. The fluorescence results showed that the binding number n was 62.1 ± 3.41 (EGCG/PC) and the binding constant K was 4.39 (±0.2) × 105 M-1, indicating a weak-binding interaction. Fourier transform-infrared analysis showed that EGCG caused structural changes in PC by partially uncoiling α-helix and increasing β-sheet content. The EGCG induced a PC association at a reaction molar ratio above 40:1 (EGCG/PC). Moreover, EGCG protected phycocyanobilin against color fading, making PE more stable relative to PC under 8-days storage in light. This study provides a novel scheme to stabilize PC by forming a complex with polyphenols, which will facilitate the PC application as a natural blue pigment in food.
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