Natural Food Pigments: From Biosynthesis to Application.

Natural food pigments primarily originate from two sources: chemical synthesis and plant-derived production. With the rapid advancement of society and technology, there is a growing demand for environmentally friendly and healthy food options. Consequently, the demand for safe, nontoxic, and sustainable sources of natural pigments has risen sharply. Natural pigments are biosynthesized during the growth and metabolic processes of plant tissues, and compounds derived from these pigments exhibit a wide range of biological activities that are beneficial to human health and disease treatment. However, due to their inherent instability and low abundance, increasing research efforts have been directed toward the bioengineering of natural pigment production. This review classifies natural pigments into five major structural categories: pyrrole, isoprenoids, quinones, phenols, and betalains. Unlike previous reviews that focused on a single pigment component or specific application fields, this review systematically integrates the biosynthetic pathways, synthetic biology strategies, pharmacological activity mechanisms, and application progress in medicine, health care, and cosmetics of natural pigment-containing medicinal materials. It emphasizes their multiple potentials as "functional pigments" in the development of natural medicines. Additionally, the review combines emerging technologies such as metabolic engineering, artificial intelligence (AI)-assisted screening, and biosensing, proposing a cross-disciplinary development path from basic synthesis to high-value applications and demonstrating strong systematicity and a forward-looking nature. It provides a new integrated perspective for innovative research on natural pigment components.