ABSTRACT
Functional foods have emerged to reflect new consumer behavior trends during the COVID-19 pandemic; these foods are beneficial to health and promote well-being beyond what regular food supplies. Natural pigments such as phenolic and non-phenolic compounds are in great demand as active ingredients for food applications because they show antioxidant, antimicrobial, anticancer, anti-inflammatory, and immunomodulatory potential. Chemical synthesis and solvent extraction of pigments from edible plants are both common approaches for producing bioactive compounds. Phenolic (e.g., phenolic acids, flavonoids, and anthocyanins) and non-phenolic (e.g., carotenoids, ascorbate, and tocopherols) compounds are commonly employed in foods. Pigment-producing microorganisms have emerged as an alternative source of bioactive compounds in recent years. In terms of extraction, the production of pigments from microorganisms has demonstrated advantages over plants because it avoids extracting bioactive molecules that are conjugated with other organic substances, such as carbohydrates, or associated with plant cell walls. Various Bacillus, Streptomyces, Pseudomonas, and Saccharomyces strains could produce a free form of bioactive pigments with high purity and productivity, allowing for easy scaling up via fermentation. Additionally, modern technology, such as metabolic engineering, could boost native strains to produce high-titer bioactive pigments. Some microbial strains (e.g., Escherichia coli and Saccharomyces cerevisiae) can also be employed as hosts for customizing the biosynthesis of antioxidants such as lycopene and β-carotene. In this chapter, we address microbial sources, improvements in the manufacturing process, and opportunities and trends in using microbial bioactive pigments in food.
