Volatile Constituents from the Fruits of Four Edible Sapindaceae: Rambutan (Nephelium lappaceum L.), Pulasan (N. ramboutan-ake (Labill.) Leenh.), Longan (Dimocarpus longan Lour.), and Mata Kucing (D. longan ssp.malesianus Leenh.)

Abstract

The volatile constituents of fruits from two Nephelium and two Dimocarpus species were analysed by capillary GC and GC-MS following isolation by vacuum distillation. In total, 48, 39, 61 and 44 constituents were identified in rambutan (N. lappaceum L.), pulasan (N. ramboutan-ake (Labill.) Leenh.), longan (D. longan Lour.) and mata kucing (D. longan ssp. malesianus Leenh.), respectively. Among rambutan volatiles, aliphatic alcohols (49.0%), sesquiterpenoids (20.5%) and carbonyl compounds (19.5%) predominated, 2-methylbut-3-en-2-ol (21.9%) and β-caryophyllene (10.4%) constituting the major components. In contrast, pulasan fruit yielded mainly aliphatic hydrocarbons (70.2%), particularly pentadecane (61.4%), and aliphatic alcohols (19.4%). Esters (68.4%) and terpenoids (27.1%) were quantitatively the most significant among longan volatiles, and ethyl acetate (66.2%) and (E)-β-ocimene (26.7%) were clearly dominant. Mata kucing differs from longan in producing much lower levels of esters (0.5%) and terpenoids (4.7%) but significantly larger proportions of aliphatic alcohols (53.2%) and carbonyl compounds (34.7%).