Variation Of Tannin Components In Fruits And Leaves Of Different Growth In ’Gongcheng’ Persimmon And Preliminary Study On The Risk Of Stomach Persimmon Stone Formation

Persimmon tannin is an important food functional ingredient,which is widely used in food,medical and other fields.Therefore,the study on persimmon tannin biological production pattern has its significance to the industry application.In addition,the clinical common cases of "stomach persimmon stone",the study of "stomach persimmon stone" mainly focused on the treatment technology,and the study of its pathogenesis is less.’Gongcheng’Persimmon is the unique cultivar in Guangxi Province,this cultivar is a typical astringent type which means it has high level tannin content.The present research took ’Gongcheng’ Persimmon as experiment material,to reveal the changes of total flavonoids,soluble tannins,insoluble tannins and tannin components in fruits and leaves with the growth and development progress.And,provided basic data for the functional development and utilization of persimmon tannin.At the same time,on this basis,explore the lithogenic mechanism of"stomach persimmon stone" to provide medical guidance for the prevention and treatment of "stomach persimmon stone".Total flavonoids,soluble tannins and insoluble tannins in flesh,peel and leaves of persimmon fruits at at young stage,expansion stage,early mature stage,mature stage and late mature stage were determined.Six tannin components such as[gallic acid(GA),gallocatechin(GC),catechin(CA),rutin(Rutin),epigallocatechin(EGC)and epigallocatechin(EC)]in all samples were quantitatively analyzed by LC-MS.Quantitative analysis of epicatechin(EC)was carried out.Subsequently,the flocculation of persimmon tannin with casein,pectin and methyl cellulose in simulated gastric juice was explored to provide reference for the formation of "stomach persimmon stone".The results show that:1.Persimmon pulp and pericarp are rich in total flavonoids,soluble tannins and insoluble tannins.The contents of these physiological indicators in persimmon fruits decreased significantly as the fruits entered the ripening stage;in contrast,the contents of persimmon leaves did not change significantly during the whole growth period.2.GA,GC and CA were detected in persimmon pulp,among which GA content was significantly higher than other components;GA,GC,CA,Rutin and EGC were detected in persimmon pericarp,among which CA content was the highest,and EGC was detected only in young stage and expansion stage;all six tannin components were detected in persimmon leaves,of which CA content was extremely high throughout the growth period,and both EGC and EC were detected in trace.It can be concluded that there are more GA components in pulp and more CA components in pericarp.Persimmon leaves can produce abundant CA tannins during the whole growth period.3.Casein,pectin and methyl cellulose can coagulate with persimmon tannin(soluble and insoluble)in simulated gastric juice to produce flocculation,and the agglomeration state is unstable.The order of flocculation strength of different parts was persimmon peel>persimmon pulp>persimmon leaf,and the stability was from big to small as persimmon pulp>persimmon peel>persimmon leaf.When no food ingredients were added,persimmon tannin could form a strong flocculation tendency in simulated gastric juice.For persimmon fruits,the flocculation of soluble tannins and food components was more intense in the early growth stage and the complex was more stable,while the flocculation of insoluble tannins with food components was stronger and more stable after ripening.The flocculation of different soluble tannins in persimmon leaves with food ingredients was more severe in the early mature stage.Among them,the flocculation strength of soluble tannin is greater than that of insoluble tannin,and the stability is stronger.In summary,the risk of persimmon tannin forming "stomach persimmon stone" was speculated:compared with persimmon leaves,eating persimmon fruit has a greater chance of stone formation.The content of soluble tannin was high at the early stage of fruit growth,and the flocculation strength of soluble tannin was stronger than that of insoluble tannin.It was concluded that eating immature persimmon fruit was easier to form "stomach persimmon stone".The soluble tannin content of astringent persimmon fruit is higher after ripening.It should be eaten on the premise of removing astringency to prevent stone formation.Deastringency of persimmon fruit is the process of transforming soluble tannin into insoluble tannin.Although the flocculation of the deastringent persimmon fruit is weakened in simulated gastric juice,a small amount of food should be taken,and food containing high casein,pectin and methyl fiber should be avoided.