Natural Food Colorant Applications in the Food Industry: Alternatives for Overcoming Stability Limitations

The replacement of synthetic dyes with natural food colorants has become a priority for the food industry, as emerging evidence from in vitro and animal studies on the potential neurotoxic and pro-inflammatory effects of certified dyes converges with consumer pressure for clean-label formulations. Yet despite this, the industrial uptake of natural pigments remains uneven, held back by stability limitations that differ considerably from one pigment class to the next and from one food matrix to another. This review covers the chemistry, industrial applications, and stabilization approaches of the main natural colorant groups: carotenoids, anthocyanins, betalains, chlorophylls, curcuminoids, phycocyanin, and genipin-derived pigments, with particular attention to the physicochemical reasons behind their instability and the practical tools available to address it. Among stabilization strategies, spray-drying microencapsulation with composite protein–polysaccharide wall materials is often the most scalable and cost-effective option, whereas freeze drying may be preferable for high-value pigments or applications in which maximum pigment retention is the priority. Whether the encapsulating matrix remains in a glassy or rubbery state stands out as a key factor governing oxidative degradation across all pigment categories, which makes water activity management a non-negotiable element of any serious formulation effort. Anthocyanins require more than physical encapsulation alone: copigmentation and structural approaches such as acylation and pyranoanthocyanin formation hold degradation routes that no shell material can prevent on its own. For hydrophobic pigments like carotenoids and curcuminoids, lipid-based delivery systems consistently deliver higher bioaccessibility than aqueous or dried formats. pH control, antioxidant incorporation, and modified atmosphere packaging add a useful but ultimately incomplete third line of defense. One development worth attention is the use of pH-responsive pigments in biopolymer packaging films, where color instability, long treated as a drawback, becomes a real-time indicator of food freshness. Bridging the remaining performance gap with synthetic dyes will call for stabilization platforms that tackle the molecular, physical, and environmental dimensions of degradation together, built around the particular chemistry of each pigment and the demands of each application.