On the Composition of Carotenoids in Loquat Fruits(Eiobotrya japanica LINDL.)

Studies on Carotenoid Pigments and Color of Fruits in Japan. Part VII

Abstract

The composition of carotenoids in loquat fruits (Mogi and Tanaka varieties) were studied qualitatively and quantitatively. The carotenoids were separated and purified by magnesia column chromatography and identified by order of adsorption affinities on magnesia and alumina, absorption spectra, color reaction test for epoxides, furanoxide transformation test of 5, 6-epoxides with ethanolic hydrochloric acid solution, and partition coefficient by Krinsky's method. Approximate contents of each carotenoid were calculated with E1% 1cm. Total carotenoid contents in Mogi and Tanaka was about 2.1 and 1.7mg%, respectively. Approximate percentage of each carotenoid to totals in Mogi and Tanaka were 33 and 31 for cryptoxanthin, 30 and 42 for β-carotene, 13 and 7 for cryptoxanthin 5, 6, 5', 6'-diepoxide, and 8 and 8 for violaxanthin, respectively. These pigments constitute principally the orange color of loquat fruits. As minor carotenoids, trollixanthin, cryptoxanthin 5, 6, 5', 8'-diepoxide, ζ-carotene, phytofluene and persicaxanthin like (unidentified) were also found in both varieties.