3^ Tannin in the Fruit of the Persimmon [Se^t 



It is important and of very great interest here that the idea 

 that tannin in the cell-sap may be associated with protein was ad- 

 vanced by Pfeffer (1886, through af Klerker, 1888), but was 

 shown by af Klerker to be open to serious question if not entirely 

 untenable. The latter however saw evidence in certain physical 

 peculiarities of the "Gerbstoffblasen" that in the plant cell tannin 

 occurs in two forms, namely as a Solution and "als nightfluessige 

 amorphe Massen oder Ballen" which, with increasing age of the 

 cells are dissolved (aufgeloest) and disappear. His final summary 

 Statement " Eine durch Plasmolyse bewirkte Ausscheidung fest- 

 weichen Gerbstoffes^^ kommt häufig in den Gerbstoff vacuolen 

 vor" indicates that he did not analyze the Situation any further, 

 though it should be said that, while he sought for other materials 

 (oils, inulin, albumin) without success, he spoke of the tannin- 

 mass, as a " Gerbstoff einschliessende Körper." 



The physical characters of the tannin-mass are those of the 

 associated colloid, aside from those, such as its possible unlimited 

 solubility or imbibition capacity, which may be influenced by the 

 presence of tannin in the combination. 



However fluid this combination may be in the unripe fruit, 

 it has a definite structure and consistence which can not be as- 

 cribed to a tannin-water Solution. In this condition, the tannin- 

 cells burst in water, and the tannin-mass escapes. From it there 

 is a synchronous escape of soluble tannin, which may appear as a 

 finely granulär precipitate. Heat suitably applied so as not to burst 

 the tannin-cells, coagulates the tannin-mass, so that it takes on much 

 the appear ance of that in the mature tannin-cell. 



During the course of ripening, the amount of free or soluble 

 tannin is reduced. So long as any free tannin is present, it may 

 escape from the tannin-mass in a manner described in detail. It 

 is shown that this escape may also occur in the undisturbed fruit. 

 The manner of escape is held to indicate its previous residence 

 within the confines of the tannin-mass itself. The formation of 

 white granulär matter on its escape is shown to be due to its com- 

 bination with a substance outside the tannin-cell, probably pectose. 

 It is shown that the free tannin in not wholly fixed, but that there is 



^ Italics are mine. 



