A COMPARATIVE STUDY OF THE PUNGENCY,MORPHOLOGY AND HISTOLOGY OF CERTAIN CAPSICUM FRUITS

This work has been carried out with a view to finding capsicum fruits which conform to the pungency requirement of the Chinese Pharmacopoeia 1953 and characters by which the presence of unofficial species or varieties of Capsicum may be detected in the form of whole fruit or powdered fruit as a substitute for or an admixture with the official variety.It was also hoped that the anatomical characters might aid the botanical classification of the commercial capsicum fruits, the origin of some of which is not yet definitely determined. Twelve samples of commercial capsicums were used in this work,viz.:(1) Fengtai capsicum,(2)Long capsicum,(3)Ox-horn capsicum,(4)Wanhsien cap- sicum,(5)Sian capsicum,(6)Hupeh capsicum,(7)Hunan capsicum,(8)Gar- den capsicum,(9)Peking capsicum——all of these capsicums are probably varieties of Capsicum annum L.——,(10)Indonesian capsicum(Capsicum frutescens L.),(11)Nanking capsicum,and(12)Capsicum B.P.(Capsicum minimum Roxb.). Detailed descriptions of their morphological and histological characters are given and the following scheme is proposed for the classification and identifica- tion of these capsicums: Class Ⅰ.Fruits dropping with a curved stalk and a distinct collenchymatous hypo- dermis A.middle lamella of the outer epidermis visible……………………………(1) (walls of the hypodermal cells with numerous pits,walls of the scleren- chymatous cells of the inner epidermis evenly thickened with few perforated pits,parenchymatous cells without pits.) B.middle lamella of the outer epidermis invisible (a)walls of the sclerenchymatous ceils of the inner epidermis unevenly thickened with numerous perforated pits……(2)(3)(4)(5)(6)(7)(8) (walls of the parenchymatous cells of the inner epidermis and of the hypodermis with numerous pits.) (b)walls of the sclerenchymatous cells of the inner epidermis evenly thicken- ed without perforated pits………………………………………………(9) (walls of the parenchymatous cells of the inner epidermis and of the hypodermis without pits.) Class Ⅱ.Fruits erect with a straight stalk and without collenchymatous hypodermis A.sclerenchymatous cells of the inner epidermis large,irregular, diameter up to 100μ…………………………………………………………………(10)(11) B.sclerenchymatous cells of the inner epidermis small,mostly oval-shaped, diameter up to 50μ…………………………………………………………(12) The significance of the above morphological and histological findings are dis- cussed and the following terms proposed: Class Ⅰ.Capsicum annuum type(including samples 1 to 9) Class Ⅱ.Capsicum frutescens type(including samples 10,11,and 12) ClassⅠincludes nine kinds of capsicum,among which,samples 2,3,4,5,6,7 and 8,in spite of their morphological differences,have similar structural features. Class Ⅱincludes three kinds of capsicum,among which,samples(10)and(11) are similar both morphologically and anatomically.Their difference in pungency may be due to horticultural environment. The pungency of the capsicums were determined according to the method described in the Chinese Pharmacopoeia 1953.For the convenience of comparison, the term“pungency ratio”is introduced.The pungency ratio is the maximum dilution(in 5 per cent sucrose solution)which produces a distinct sense of pun- gency in the throat of at least two out of three individuals. The pungency ratios of the twelve samples of capsicum were found to be as follows:(1)60,(2)20,(3)5,(4)50,(5)60,(6)30,(7)60,(8)0,(9) 20,(10)25,(11)35,(12)50.Therefore,among the capsicums tested,only the Feagtai capsicum,Wanhsien capsicum,Sian capsicum,Hunan capsicum and Cap- sicum B.P.conform to the pungency requirement of the Chinese Pharmacopoeia 1953.