Stabilizing and Modulating Color by Copigmentation: Insights from Theory and Experiment

Area of Science:

• Food Chemistry
• Natural Pigments
• Molecular Interactions

Background:

• Anthocyanins and phenolic compounds are natural pigments and copigments, respectively.
• These compounds form noncovalent complexes, influencing color stability and modulation in natural products and foods.
• The phenomenon of copigmentation is crucial for color properties in berries, flowers, and derived food products like wines and jams.

Purpose of the Study:

• To provide a comprehensive review of the copigmentation phenomenon.
• To elucidate the molecular mechanisms underlying pigment-copigment interactions.
• To highlight the significance of copigmentation in food chemistry applications.

Main Methods:

• Review of experimental and theoretical studies on copigmentation over the past decade.
• Analysis of the nature of binding, including π-π stacking, hydrophobic effects, and hydrogen bonding.
• Examination of spectral modifications in copigmentation complexes, emphasizing charge transfer.

Main Results:

• Detailed description of noncovalent binding interactions between anthocyanin pigments and phenolic copigments.
• Explanation of spectral shifts and color modulation resulting from copigmentation.
• Identification of charge transfer as a key factor in spectral modifications within copigmentation complexes.

Conclusions:

• Copigmentation is a key phenomenon for understanding and controlling color in natural products and foods.
• Molecular interactions, including π-π stacking and charge transfer, are central to copigmentation.
• Applications in food chemistry are significant, offering insights into color stabilization and enhancement.