Method for preparing persimmon tannins with high micromolecular tannin content from persimmons

Abstract

The invention discloses a method for preparing persimmon tannins with high micromolecular tannin content from persimmons. The method comprises the steps of raw material treatment, high-pressure micro-jet ultrafine crushing treatment, fermentation treatment, enzymolysis, microfiltration, ultrafiltration and drying. According to the method, a production process is improved, so that extraction time is shortened, the yield of the product is increased, the content of condensed tannins with molecular weight of 10,000-15,000 is ensured, and in addition, the content of low molecular weight tannins with molecular weight of 1,700 is also ensured.

Description

technical field [0001] The invention relates to a method for preparing persimmon tannin, in particular to a method for preparing persimmon tannin with high content of small molecule tannin from persimmon. Background technique [0002] Persimmon is a temperate deciduous fruit tree of Persimmonaceae berry class. It is native to my country and has a planting history of more than one thousand years in my country. At present, my country has the largest planting area and the largest persimmon fruit output. Persimmons are tender and juicy, sweet and refreshing, and rich in nutrition. There are two kinds of sweet persimmons and astringent persimmons. Astringent persimmons cannot be eaten directly and need to be deastringent. Sweet persimmons can be eaten fresh, or made into persimmon cakes, persimmon vinegar, persimmon wine, etc. Persimmon leaves can be made into persimmon tea. Persimmons contain a lot of tannins. Tannin, also known as tannin, is a polyphenolic polymer, which is...

AI Technical Summary

Problems solved by technology

The traditional and commonly used methods for extracting persimmon tannins with high content of small molecular tannins mainly include acid extraction, alkali extraction and water extraction, etc. Among them, hot water extraction is the most common method, and acid and alkali extraction will destroy the structure of persimmon tannins, and at the same time It has an impact on the content of sulfate radicals; while the extraction rate of hot water extraction is generally low, it is difficult to meet the production needs

Generally, after water or alcohol extraction, the extract must go through a series of processes such as adsorption, rinsing, and elution after decompression and concentration, especially repeated rinsing with distilled water until the eluate cannot detect sugar by the phenol-sulfuric acid method. So far, the operation process is cumbersome, otherwise, in the later drying process, due to the high proportion of sugar content in the persimmon tannin concentrate, the dryer "sticks to the wall" seriously, and the material cannot be dried and solidified

Chinese patent CN102550993B discloses a method for preparing astringent persimmon powder with a high content of small molecular tannins. It is to wash, crush, and squeeze the seven or eight ripe persimmons, compound enzymatic hydrolysis, color protection, filtration, and enzyme and sterilization , vacuum degassing to obtain the raw persimmon juice, and then the raw persimmon juice is subjected to microfiltration, ultrafiltration, and freeze-drying to obtain astringent persimmon powder with a high content of small molecule tannins, but this method is relatively simple for the pretreatment of raw materials of persimmons. Affect the final product content and yield

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