The essential oil in the peel and pulp of a popular green Thai mango, Khieo Sawoei cultivar (Mangifera indica L.) has been characterized by means of the odor thresholds. ␥-Terpinene, (E)--ocimene, (E)-2-hexenal, hexanal, and (Z)-3-hexen-1-ol were the major components. These major components differed from those of African mangoes, Florida mangoes, Indian mangoes and yellow Thai mangoes. The volatile oils from the pulp and the peel showed a high similarity of the volatile components in both sites. Odor unit values (U o ) of volatile components in both parts let us find out the aroma potent components in the Khieo Sawoei mango. Thus, nine compounds: hexanal (U o )981؍ and (E)-2-hexenal (U o )231؍ in the pulp showed higher U o values (more than 1), while sixteen compounds: 2,4-decadienal ( Keywords: Mangifera indica L., Thai mango, Khieo Sawoei cultivar, peel oils, pulp oils, odor spectrum value, odor unit A number of volatile components from several kinds of mango fruits have been identified in past decades (Schreier & Idstein 1984;MacLeod & Snyder 1988b;Shibamoto & Tang, 1990). New techniques such as headspace analysis (Malundo et al., 1997;Vodovotz et al., 1993) and measurement of bound aroma compounds (e.g. glycosides; Adedeji et al., 1992) have been applied for the isolation and characterization of volatiles. In these various varieties, there is considerable variation in volatile composition and aroma quality. However, few studies concerning the volatiles in Thai mangoes have appeared in the literature. Recently, antioxidant compounds in mango peel fibres were reported to have beneficial effects on health in high-dietary-fibre diets (Larrauri et al., 1997). Gholap and Bandyopadhyay (1977) studied on the volatiles in the latex of green raw mango. Utilization of mango peels for industrial purpose (Rashad et al., 1990) must be encouraged more than before. Therefore, we demonstrated the possibility of utilization of the peel oils to improve the aroma quality of processed Thai mangoes.In Thailand, green mangoes are consumed in significant quantities as well as the yellow mangoes at the mature stage. Keaw species is the major greenish cultivar used for processing; Khieo Sawoei cultivar is a high quality cultivar for matured green mangoes in Thai markets. We have not found any papers reporting studies on the volatile compositions and aroma profiles of green mangoes. This paper deals with the identification and characterization of volatile components in a green Thai mango, Khieo Sawoei mango using odor unit values and odor spectrum values of the volatile components in the peel and the pulp.
Materials and MethodsMaterials The Khieo Sawoei mangoes used in this study were obtained from a local market in Bangkok, Thailand in November 1996 and May 1997. This fruit can be harvested all year long in Thailand. The fresh fruits were frozen quickly at Ϫ20˚C and then transferred to Japan, where they were peeled and sliced. Finally, the fruit pulp was removed from the stone. The peel and the pulp were kept in a freezing room ...