Nectarine lactones

Peaches and nectarines are members of the same species (Prunus persica). There is controversy over whether nectarine is a separate and distinct fruit or merely a variety of peach [68]. Nectarines lack skin fuzz or pubescence. Approximately 100 volatile compounds have been identified in peaches and nectarines, including alcohols, aldehydes, alkanes, esters, ketones, lactones and terpenes [14, 15, 17, 64, 65, 68-71]. Among them, lactones, particularly y-decalactone and d-decalactone, have been reported as character-impact compounds in peaches and nectarines where they process a strong peach-like aroma [66]. Lactones act in association with Ce aldehydes, aliphatic alcohols and terpenes (Table 7.2,... 

Schottler M, Boland W (1996) Biosynthesis of dodecano-4-lactone in ripening fruits Crmal role of an epoxide-hydrolase in enantioselective generation of aroma components of the nectarine ( Prunus persica var. nucipersica ) and the strawberry (Fragaria ananassa). Helv Chim Acta 79 1488... 

The taste of ripe peaches is dominated by the sweet succulent juice with its very aromatic fmity and fresh aroma. The heavy fruity, fatty, typical peachy note, also found in plums, nectarines, apricots is called lactony , and it is derived from gamma-lactones. 

Alkanolides (hydroxyalkanoic acid lactones), y- and 6-lactones usually occur together in flavors, as well as in flower extracts, e. g. tuberose absolute. In fruit flavors such as apricot, mango, nectarine, and peach 4-A. are more frequent, while in butter and coconut flavor the 6-lactones predominate. The lactones Cg-C 2... 

The aroma of peaches is characterized by y-lactones (C6-C12) and 5-lactones (Cio and Cl2). The main compound in the lactone fraction is (R)-l,4-decanolide, which has a creamy, fruity, peach-like odor. Other important compounds should be benzaldehyde, benzyl alcohol, ethyl cinnamate, isopentyl acetate, linalool, a-terpineol, a- and 3-ionone, 6-pentyl-a-pyrone (Formula 18.39, VIII), hexanal, (Z)-3-hexenal, and (E)-2-hexenal. Aroma differences in different varieties of peaches are correlated with the different proportions of the esters and monoterpenes. In the case of nectarines (Prunus persica L., Batsch var. nucipersica Schneid), the lactones y-C8-Ci2 and 5-Cio belong to the compounds with the highest aroma values. 

Epoxide hydrolases have been found in such plants as soy bean [40] or in nectarines and strawberries, where they play a crucial role in the enantioselective synthesis of lactone aroma compounds [55]. Furthermore, epoxide hydrolases are involved in the biosynthesis of cutin, a polyester found in the cuticle that forms the first physical barrier against plant infection [56]. It has also been proposed that epoxide hydrolases may be involved in the production of microbial toxins [57]. 

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