Food color is often associated with the product’s flavor, safety, and nutritional value. Due to their high consistency and low cost, synthetic food colorants have been used. Consumer awareness and demand, though, have motivated the substitution of synthetic dyes with natural alternatives. Little consistency, lower tinctor strength, interactions with food ingredients, and inability to fit preferred hues can restrict natural pigment applications. Any particular naturally derived colorant can, therefore, function in all applications as a standardized solution to a common synthetic colorant.
This analysis draws together major environmental and biological outlets for natural colorants as well as equivalents that are similar. It describes the chemical properties of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls. Often addressed are possible applications and hues (warm, dark, and achromatic) of commonly used natural pigments such as anthocyanins as red and blue colorants, as well as possible future substitutes such as violet violacein and red pyranoanthocyanins.
Some natural colors are vegetable dyes from plant roots, fruit, moss, herbs, and wood, as well as other agricultural materials such as fungi and lichens. More than 500 species of plants are known as sources of coloring. Natural colors are mostly non-substantial and must be added to textiles using mordant, typically a synthetic powder, which has an attraction for both the coloring medium and the fiber.
Many natural colorants do not have any significant use of a mordant on cellulose or other clothing fibers. They need the mordanting chemical to establish an association between the fiber and natural colorant molecules.
Aluminum sulfate or other metallic mordant attached to any fiber; mix chemically with certain mordant capable, functional groups found in the natural colorants and connected by coordinated / covalent bonds or hydrogen bonds and other contact powers. Therefore, in most situations, mordanting is necessary to fix natural colorants on any textile fabric properly.
Natural colorants are mostly biodegradable, environmentally friendly, and less resistant relative to synthetic dyes. Research studies have shown that some natural colors have mutagenic properties such as yellow safflower; other mutagens contribute to cancer; others such as carmine may induce asthma through prolonged inhalation. However, it can be said that certain natural colors are harmless, and some also have curative benefits, e.g., curcumin has antibacterial properties in turmeric.
While natural colors have several advantages compared to synthetic colors, the use of natural colors is very restricted due to the lack of standard shade cards and traditional textile content application procedures.
Importance of natural colorants
In most of the world’s ancient civilizations, such as Asia, China, Mesopotamia, Egypt, Persia, Aztec, and others, natural colorants have been used. The use of natural colorants for cosmetic and other uses is at least 15,000 years old, known from red ock discovery in ancient burial sites.
It is believed that dying cloth art has been known in China since 3000 BC and in India since 2500 BC. Throughout China, dyeing has been traced back over 5,000 years with herbs, barks, and insects.
Throughout China, the written record of natural colorant use was identified dating back to 2600 BC. The dyeing of fabric in black, purple, brown, and green was also done in Egypt at the same time (2000 BC).
Indigo is the oldest and most commonly produced natural colorant; it has been used in India for the last 4000 years. A blue dye known as the’ woad’ has been used since the bronze age in northern European countries such as Denmark, Norway, Finland, Ireland, and the UK, etc. Another ancient pigment, the Tyrian purple, came from the genera Purpura Mediterranean shellfish, and Murex was probably the most expensive dye source in history.
Indigo is one of the oldest natural colors used in textile dyeing and printing. Indigo is a 2-3-foot-long plant grown on thousands of acres of India’s land. The entire plant is used to remove the dye, and the dye’s extract medium is provided in the form of powder.