How Can We Obtain High-grade Quercetin?

What is Quercetin?

Quercetin is a natural pigment found in many vegetables, fruits and grains. Quercetin 98% Extract Powder is one of the most plentiful antioxidants in the diet and plays an outstanding role in helping your body fight free radical damage associated with chronic disease. Additionally, its antioxidant properties may assist in reducing inflammation, allergy symptoms, and blood pressure.

Quercetin compound is classified as a flavonol which is one of six subclasses of flavonoid compounds. The name has been in use since 1857 and is derived from the oak tree. Quercetin (C15H10O7) is an aglycone without sugar. It is a bright citron yellow needle-like crystal, completely insoluble in cold water, hardly soluble in hot water, but easily soluble in alcohol and lipids. Quercetin glycoside is formed by attaching a glycosyl group (a sugar such as glucose, rhamnose or rutinose) as a replacement for one of the OH groups (usually in the 3rd position). Attached glycosyl group can alter solubility, absorption, and in vivo effects.

What are quercetin rich foods?

Quercetin flavonoid, the most plentiful flavonoid molecules and are widely distributed in plants. They are present in many foods, including berries, apples, brassica vegetables, onions, grapes, tomatoes, shallots, tea, as well as a variety of seeds, nuts, bark, flowers, and leaves. Quercetin is also found in medicinal plants, including Hypericum perforatum, Ginkgo biloba, and Canadian elderberry. In red onions, higher concentrations of quercetin were found in the outermost rings and in the part closest to the root, which is the part of the plant with the highest concentration. One study found that organically grown tomatoes had 79% more quercetin than chemically grown fruits. Food sources of quercetin include vegetables, fruits, berries, nuts, beverages, and other plant-derived products.

How Can We Obtain High-grade Quercetin?

After painstaking research and multiple verifications, we have found a production process that can obtain high-quality quercetin with a purity of more than 95%, which is completely suitable for food and pharmaceutical raw materials.

The production process comprises the following steps: feeding→hydrolysis→filtration→washing→refining. Specific steps are as follows:

★ Feeding: Mix inorganic strong acid and water to obtain acid-water mixture, add rutin after being heated to boiling;

Wherein, the rutin feeding amount is: every 1kg rutin adds acid-water mixture 7-15L; The hydrogen ion concentration in the acid-water mixture is 0.4-lmol/L (preferably 0.5-lmol/L, further can preferably 0.7-lmol/L). The inorganic strong acid that can be adopted is hydrochloric acid or sulfuric acid. In order to fully hydrolyze, the liquid is kept under stirring.

★ Hydrolysis: Keep boiling for at least 1 hour; preferably keep boiling for 2 to 3 hours to fully hydrolyze.

★ Filtration: The hydrolyzed solution was filtered, and the filtrate was used for later use.

★ Washing: The filter cake obtained after filtration in 60-70℃ (preferably 70℃) is washed with water. Stop washing until the pH value of the eluate is neutral, then dry to obtain the quercetin crude filter cake. It is easy to remove water-soluble impurities under controlled temperature.

★ Refining: Put the quercetin crude filter cake into 5~15 times the amount of refined methanol. Stir well, stand and filter. First, the filter cake is washed with 2~10 times the amount of refined methanol, and then wash it with 5 to 10 times the amount of pure water until it is colorless and odorless. Lastly, dry to obtain high-grade quercetin product.

The advantages of this production process are as below:

1. Environmentally friendly, no harmful substances and pollutants are discharged.

2. Simple, easy to control, high conversion rate, can greatly reduce costs.

3. The obtained product has high purity, and impurities and bacteria meet the relevant standards.