In the UV visible region, there are three absorption peaks of gardenia yellow in aqueous solution: 238nm, 325nm and 440nm, which are the characteristic absorption peaks of geniposide, chlorogenic acid, Flax lignans and crocetin respectively.
Food Colour Crocus Sativus solution is orange yellow at pH 1 ~ 7 and bright yellow at pH 8 ~ 12. The stability of the pigment was poor under acidic conditions, but good under neutral and alkaline conditions. Similar to other carotenoids, gardenia yellow had poor sunlight tolerance. Except for Fe and Cu, common metal ions had no effect on Gardenia yellow.
When gardenia yellow solution coexists with oxidant, Mangiferin will fade due to oxidation. Therefore, if gardenia yellow is used in food, it is necessary to avoid contact with oxidants during processing and storage, so as to delay or reduce the fading of gardenia yellow.
In the food system with Beet Root Powder as dye, ascorbic acid and sodium isoascorbate can significantly delay the color fading. Therefore, on the premise of not affecting the flavor and other quality indexes of the product, proper amount of antioxidant can be added to prevent or delay the fading of gardenia yellow.
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