Method for extracting persimmon tannin high in small molecular tannin content from persimmon

Abstract

The invention discloses a method for extracting persimmon tannin high in small molecular tannin content from persimmon. The method comprises the steps of raw material treatment, ultrahigh pressure treatment, ultrasonic treatment, enzymolysis, microfiltration, ultrafiltration and drying to obtain the finish product. According to the method for extracting the persimmon tannin high in small molecular tannin content from the persimmon, two extraction methods are combined, and therefore, the extraction time is shortened on one hand, and on the other hand, the product yield is obtained, the content of the condensed tannin having the molecular weight within the range of 10000-15000 is guaranteed, and meanwhile, the content of the tannin having the low molecular weight of 1700 is also guaranteed.

Description

technical field [0001] The invention relates to a method for extracting persimmon tannin, in particular to a method for extracting 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 ...

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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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