strawberry red pigment
Physical and chemical properties
Red paste or solution, no difference.
- Soluble in ethanol, acetic acid, acetone, red;
- Soluble in water, milk, orange-yellow;
- Dissolved in pasty cream, orange-red;
- Insoluble in ethyl acetate peanut oil and sodium carbonate solution, it is dark orange-red when pH=1~4, light orange-red when pH=5~6, light pink when pH=7, and pH=8-9 Light red flesh, light purple red when pH=10~11, dark purple red when pH=12, dark red flesh when pH=13-14.
When the pH was above 7, a white precipitate formed. It is relatively stable under acidic and neutral conditions, but unstable under alkaline conditions.
The heat resistance is not good at high temperatures, and it is relatively stable when it is below 60 °C. When it is higher than 70 °C, the color gradually becomes lighter, that is, high temperature has a certain degradation effect on the pigment.
Sunlight also degrades strawberry red pigment, and CaCl2 and Fe(NO3) 2 have a slight effect on its color.
As a red colorant, it can be used for coloring food, beverages, children’s toys, etc.
Extraction Method of Red Pigment in Strawberry
- Distilled water
- Hydrochloric acid
Electronic constant temperature water bath
Raw material → Pretreatment → Leaching (Solid-Liquid Extraction)→Filtration → Concentration → Centrifugation → Evaporation → Finished product
- Raw material: Fresh strawberries
- Pretreatment: Wash the strawberries and remove the stems, drain and weigh 1kg, and crush to obtain about 1L of solution.
- Extraction and filtration: Add 2L of 80% ethanol to the solution to extract for 2h, and filter to obtain a transparent red filtrate.
- Concentration: The filtrate was heated in a water bath at 40°C for about 40min
- Centrifugation: Centrifuge the concentrate for 20min, take the supernatant, and add hydrochloric acid to adjust pH=2.0
- Evaporation: Rotate the supernatant at 50°C until the solution is paste-like to obtain the pigment