Cultivar Difference of Carotenoids in Loquat Fruits

Abstract

(1) The compositions of carotenoid in cultivars 'Toi' and 'Tanaka' at the fu lly mature stage were investigated by TLC method. The total carotenoid contents in the peel and the pulp of 'Toi' were lower than those of 'Tanaka'. It could be considered that the light color of 'Toi' was attributed to the lower carotenoid contents. The main carotenoids in both the peels were 61% and 87% in β-carotene, 3% and 8% in cryptoxanthin, and 21% and 2 % in lutein for 'Toi' and 'Tanaka', respectively. The carotenoids in the pulp wer e mainly composed of β-carotene 32% and 55% and cryptoxanthin 52% and 25% for 'Toi' an d'Tanaka', respectively. (2) The compositions of carotenoid were studied in the peel and the pulp of 'Tanaka' during maturation. The carotenoid content in the peel decreas ed with the decrease in chlorophyll in the peel. It increased rapidly when the peel color ch anged from green to yellow, and subsequently the color turned yellow-orange. Lutein which w as a main carotenoid at green stage decreased gradually as color changed. On the other han d, β carotene which was secondary in quantity at the immature stage showed similar ch anges in the content as total carotenoid contents and it became a predominant carotenoid at the mature stage. The change of β-carotene in the pulp showed a straight rising cur ve with no decrease during maturation. The cryptoxanthin content was at a low level in the immature stage, but it rapidly increased and it became a main component in the fully matu re stage.