Method for preparing theaflavin

Abstract

The invention provides a method for preparing theaflavin. The method is characterized by comprising the following steps that (1) a polyphenol oxidase emulsion is prepared; (2) a tea polyphenol alcoholic solution is prepared; (3) the polyphenol oxidase emulsion and the tea polyphenol alcoholic solution are evenly mixed according to the mass ratio of 1:(0.5 to 2.0), the pH value is adjusted to be 4.0-6.5, air or oxygen is introduced at 25-35 DEG C with the amount of 0.5-2 units / min, and fermentation is conducted for 20-80 min; (4) still standing is conducted for 2-5 h, supernatant is taken, filtered, concentrated and diluted with purified water till a solid type object is 3%-6%; and (5) chromatography, elution, concentration and drying are conducted. The fermentation synthesis rate of the theaflavin is high, purification is easy, residue is avoided, safety and reliability are achieved, a technology is simple, and the production cost of the theaflavin is significantly lowered.

Description

technical field [0001] The invention relates to a method for preparing theaflavins, belonging to the field of biotechnology. [0002] technical background [0003] Theaflavins (theaflavins, TFs) were first discovered by Roberts E.A.H (1957). It is a compound formed by the oxidation of polyphenols that can dissolve in ethyl acetate and is orange-yellow and has a benzotropolone structure. general term. There are 25 components of theaflavins whose structures have been clarified, the main components of which are: theaflavin (theaflavin, TF), theaflavin-3-monogallate (theaflavin-3-gallate, TF-3- G), theaflavin-3'-mono-gallate (theaflavin-3'-gallate, TF-3'-G) and theaflavin-3,3'-bis-gallate (theaflavin-3,3' -gallate, TF-3,3'-G) and epitheaflagallin-3-gallate (TF4), etc. The content of theaflavins in black tea is generally 0.3% to 1.5%. They are the main components in black tea and play a decisive role in the color, aroma and quality of black tea. Fragrance and freshness, known ...

AI Technical Summary

Problems solved by technology

Extraction method: Due to the low content of theaflavins in black tea, it is difficult to directly extract and purify theaflavins from black tea, and the yield is low

Chemical oxidation method: It needs to use a large amount of chemical reagents such as potassium ferricyanide, ferric oxide, magnesium oxide, acid and alkali, etc., the environmental pollution is serious, and more sewage treatment costs need to be invested, and because the chemical method lacks substrate specificity, The by-products are complicated, and the product purity and safety are limited

The enzymatic oxidation method has mild reaction conditions and strong controllability, and can avoid the disadvantages of the above two methods, but enzymatic oxidation is a relatively suitable method, which is mainly divided into single-liquid phase fermentation and two-liquid phase fermentation. Two-liquid phase fermentation" refers to the addition of a new, water-immiscible ethyl acetate oil phase to the fermentation broth. Compared with single-liquid phase fermentation, two-liquid phase fermentation is more effective in aerobic fermentation and in increasing It has great advantages in mass transfer and fermentation yield. However, the residue of ethyl acetate limits the use and export, and cannot meet customer needs; while single-liquid phase fermentation has low conversion rate, difficult purification, and low product purity. problems, which limits its application in products

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