Insight into the Progress on Natural Dyes: Sources, Structural Features, Health Effects, Challenges, and Potential

Abstract

(1) Background: Dyes play an important role in food, medicine, textile, and other industries, which make human life more colorful. With the increasing demand for food safety, the development of natural dyes becomes more and more attractive. (2) Methods: The literature was searched using the electronic databases PubMed, Web of Science, and SciFinder and this scoping review was carried out following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). (3) Results: 248 articles were included in this review. This review summarizes the research progress on natural dyes in the last ten years. According to structural features, natural dyes mainly include carotenoids, polyphenols, porphyrins, and alkaloids, and some of the newest dyes are summarized. Some pharmacological activities of carotenoids, anthocyanin, curcumin, and betalains in the last 10 years are summarized, and the biological effects of dyes regarding illumination conditions. The disadvantages of natural dyes, including sources, cost, stability, and poor bioavailability, limit their application. Here, some feasible strategies (potential resources, biotechnology, new extraction and separation strategies, strategies for improving stability) are described, which will contribute to the development and utilization of natural dyes. (4) Conclusion: Natural dyes show health benefits and potential in food additives. However, it is necessary for natural dyes to pass toxicity tests and quality tests and receive many regulatory approvals before their final entry into the market as food colorants or as drugs.

Actinomycins from Soil-Inhabiting Streptomyces as Sources of Antibacterial Pigments for Silk Dyeing

“…As they are renewable and biodegradable, microbial dyes can be substituted. Microbial dyes may possess antimicrobial properties, so they could be a good and readily accessible source of natural dyes [ 45 ].…”

Furylogous Nucleophile Chemistry for the Preparation of Renewable Dyes

“…However, agriculture is resource-intensive (land, water, and energy) and often involves the use of chemical fertilizers and pesticides. Natural dyes are also expensive, are limited in color selection, require the use of mordants, and often show inferior performance. , It may be noted here that, as a reaction to these concerns, microbiologically produced colorants are being introduced into the market. , However, similar issues involving cost, limited color range, and constraints in production volume would suggest that this is not a comprehensive solution to the problem. Between these two extremes are synthetic dyes that are fully sourced from biomass-derived intermediates.…”

“…2,3 It may be noted here that, as a reaction to these concerns, microbiologically produced colorants are being introduced into the market. 4,5 However, similar issues involving cost, limited color range, and constraints in production volume would suggest that this is not a comprehensive solution to the problem. Between these two extremes are synthetic dyes that are fully sourced from biomass-derived intermediates.…”

Molecular cloning and functional characterization of BcTSA in the biosynthesis of indole alkaloids in Baphicacanthus cusia

“…Indigo (also known as indigotin) exhibited anti-inflammatory activities in vitro ( Li et al., 2022 ). Indigo, is also a dye that has been cherished since antiquity for its brightness and deep blue color and has also been used for 6,000 years.…”