Views:3 Author:Site Editor Publish Time: 2021-05-05 Origin:Site
Study on the Stability of Edible Roselle Red Pigment
With the development of science and technology, it is a general trend that synthetic pigments are gradually replaced by natural pigments. It's of great significance to develop the safe and reliable natural pigments to guarantee people's health.
Roselle (Hibiscus sabdariffa), also known as mountain stalk and red horned sunflower in China, is an annual herbaceous plant of the genus hibiscus in the Malvaceae family. It is native to Africa and has been planted in large areas in Fujian, Guangdong, Guangxi, Yunnan, Zhejiang and other provinces in China in recent years.
The calyx of Hibiscus sabdariffa is purple-red, and its pigment belongs to anthocyanins, which is the same as grape, strawberry, cherry and other fruits. It's total anthocyanin content is 1%~1.5% of dry calyx, with organic acids such as citric acid and hibiscus acid at 10%-15%, 16% reducing sugar, 3.5%-7.9% protein, 25% other non-nitrogen-containing substances, 11% Fiber,12% total ash, and 7 kinds of amino acids less than 1%.
This paper studies the effects of pH, metal-ion, light and heat on the stability of roselle red pigments, and the effectiveness of reagents and food additives on the stability of roselle red pigments, which provides a scientific basis for improving the stability of roselle red pigments in food.
1. Materials and methods
1.1.1 Roselle flower Provided by Zhejiang Citrus Research Institute.
1.1.2 Apparatus Model 721 spectrophotometer, PHS-3C precision, PH meter.
1.1.3 Reagents (analytical purity +):
36% hydrochloric acid, citric acid, ferric chloride, calcium chloride, zinc chloride, sodium chloride, magnesium chloride, aluminum chloride, manganese chloride, copper chloride, dichloride Tin, tin tetrachloride, VC, hydrogen peroxide, anhydrous sodium sulfite, anhydrous sodium carbonate, sodium benzoate, sodium hydroxide.
1.2.1 Roselle anthocyanin extraction method
Weigh 10.00g of cut dry calyx, add 100ml 1.5% HCL solution, soak in 50℃±2℃ constant temperature water bath, take it out after 4 hours, filter, and dilute to 100nl, from it Aspirate 1ml and dilute to 100ml as the measurement solution.
1.2.2 Spectral analysis of roselle red pigment
Scan the roselle red pigment measurement solution in the wavelength range of 400-590nm to obtain the absorption spectrum of the pigment.
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