Survey of Phenolic Compounds Produced in Citrus
Flavonoid Composition of Citrus

Pummelo (Citrus grandis), a primary Citrus species, is reportedly one of the three species (in addition to sour orange and Poncirus trifoliata) that accumulate neohesperidosyl glycosides (Albach and Redman 1969). According to previous studies, naringin is the major flavanone in most pummelo cultivars (Mizelle et al. 1965, Albach and Redman 1969, Nishiura et al. 1971a, Kamiya et al. 1979, Park et al. 1983). Neohesperidin, poncerin, and naringin– 4'–glucoside may also be present (Albach and Redman 1969, Nishiura et al. 1971a,b, Park et al. 1983, Kumamoto et al. 1986). Naringin is the major flavanone component in pummelo cultivars examined in this study, except in the 'Red Fleshed' pummelo, where the concentration of neoeriocitrin roughly equals that of naringin. There are also significant amounts of naringin–4'– glucoside, hesperidin, neohesperidin, and naringin–6"–malonate. The presence of small concentrations of eriocitrin and narirutin, along with hesperidin, shows that pummelo is capable of synthesizing rutinosyl glycosides.

Several hybrid cultivars of pummelo have greater amounts of rutinosyl flavanones (such as hesperidin in the 'Red Aranyan' hybrid) than pummelos themselves. Using thin-layer chromatography, Albach and Redman (1969) detected naringin and neohesperidin in pummelo and narirutin–4'–glucoside, hesperidin, naringin, poncerin, and neohesperidin in a pummelo × sweet orange cross. Rousseff et al. (1987) obtained similar results. Our results confirm the observation that, while most pummelos have neohesperidosyl flavanones, low and trace levels of rutinosyl flavanones can also occur, with larger percentages occurring in those pummelo hybrids produced from parental cultivars that accumulate rutinosyl flavanones.

Pummelo cultivars (such as 'Deep Red', 'Fleming', 'Kao Panne', 'Moanalua', 'Red Fleshed', 'Siamese Seedless', and 'Tahitian'), but not necessarily their hybrids, contain the naringin-like flavone rhoifolin. Several cultivars designated as pummelo hybrids (such as 'Philippine', 'Red Aranyan', 'Yuma Ponderosa Lemon') may also contain rutin and isorhoifolin. Other pummelo hybrids, such as the crosses between pummelo and lemon and the crosses between pummelo and orange, contain primarily rhoifolin.

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United States Department of Agriculture
Agricultural Research Service

The material on this page is in the public domain.

Original posting: April 1, 1999.