Pyrus pyrifolia (Burm.) Nak. - syn.Pyrus serotina Rehder - Rosaceae
沙梨 sha li (chin.), ナシ (梨) nashi (jap.), nashi pear, China pear, Asian pear, Nashi-Birne, China-Birne

Tree, up to 15m high, native to China, Laos and Vietnam; flowers white; fruit subglobose, brownish with pale dots, 3.5–5.5 cm in diam. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200011195

„Along with cultivars of P. × bretschneideri and P. ussuriensis, the fruit is also called the nashi pear.“ Wikipedia

Dynamic headspace sampling of vacuum steam distillated extracts of intact and blended Asian pear fruits showed ethyl propanoate, ethyl butanoate, ethyl hexanoate, butyl acetate, ethyl 2-methylbutanoate, hexyl acetate, ethyl octanoate, ethyl (Z)-4-decenoate, and ethyl (E)-2,4-decadienoate as the main components. Calculated OAV indicated that most important contributors to Asian pear aroma are (OAV): ethyl 2-methylbutanoate (37000), ethyl hexanoate (9427), ethyl butanoate (4756), ethyl 2-methylpropanoate (760), hexyl acetate (492), ethyl heptanoate (39), hexanal (37), ethyl pentanoate (27), ethyl propanoate (26), 3-methylbutylacetate (13), butyl acetate (13), (E)-2-hexenal (7), ethyl octanoate (6), ethyl (E,Z)-2,4-decadienoate (6), and octyl acetate (3).
„Due to its particularly low odor threshold of 0.006 ppb, ethyl 2-methylbutanoate appears to be an important contributor to pear aroma… Analysis of fresh pear extract obtained by vacuum SDE revealed that ethyl 2-methyl-butanoate occurred in exclusively the S(+) configuration. Earlier studies had shown that this important ester is also present in exclusively the S(+) configuration in pineapple (Takeoka et al., 1990) and predominantly in the S(+) configuration in Granny Smith apples (Mosandl et al., 1991).“
[ Volatile constituents of Asian pear (Pyrus serotina)., Takeoka, G. R., Buttery, R. G., Flath, R. A., Journal of Agricultural and Food Chemistry, Vol.40(10), 1992, 1925-1929]

Nashi pear, author: katorisi https://commons.wikimedia.org/wiki/Pyrus_pyrifolia CC BY-SA 3.0