The Gardenia is popular as a garden plant and is known for its beautiful white flowers and exotic scent. An evergreen shrub, it is thought to have originated in China and Japan, but can also be found in the tropical and subtropical regions of Africa and Australia,Asia.
Gardenia blue is a natural blue colorant extracted from the fruit of the plant Gardenia jasminoides Ellis, also known as cape jasmine. It is obtained by extracting compounds called genipin from the gardenia fruit and combining them with proteins or amino acids, which results in a bright blue pigment.
Gardenia blue is used widely in food coloring, especially in Asia, and is approved by regulatory authorities like the FDA for use in foods such as sports drinks, flavored waters, fruit drinks, teas, hard and soft candies, and baked goods. It offers a natural alternative to synthetic blue dyes, with good stability in pH ranges (pH 3-8), heat resistance, and light resistance.
In textile dyeing, gardenia blue can produce rich ocean blues on wool and silk, and lighter sky blue hues on cotton by adjusting conditions such as pH and mordants.
Chemically, gardenia blue consists primarily of a polymer formed by genipin molecules linked to peptides, with a molecular weight of about 15,000 to 30,000 daltons. It has been shown to have no significant genotoxic or toxic effects in studies with prolonged exposure, making it considered safe for food use.