The present paper describes the results of experimental work on the nature of skin pigments of Delaware, Campbell Early, Muscat Bailey A and Red Millennium which are main varieties of table grape vine in Japan.
In regard to the skin pigments, solubility for some organic solvents and specific color reactions of anthocyanin and carotinoid, were examined. Results of these qualitative analyses showed that the skin colors of these varietes ranging from red to deep reddish purple are caused by anthocanin and carotinoid has scarsely any relation to the development of them.
Then skin pigments extracted by methanolic hydrochloric acid were separated by paper chromatography. Filter papers of Toyo No.50 were always employed and a mixture of butanol, hydrochloric acid and water (5 : 1 : 2) and a mixture of butanol, acetic acid and water(4 : 1 : 2) were used as developer for anthocyanin and a mixture of 80% formic acid, hydrochloric acid and water (5 : 1 : 4) was used for both anthocyanin and anthocyanidin.
From this study it was found that at least three kinds of anthocyanins are present in the skin of Delaware and Red Millennium, eight in Campbell Early and seven in Mascat Bailey A. And also the results indicated that major anthocyanins of Delaware and Red Millennium are cyanidin-deliverties, that of Campbell Early are cyanidin and delfinidin deliverties and that of Muscat of Bailey A are paeonidin and malvidin deliverties.