## 2 Aroma Volatile Composition and Their Biological Characteristic of Major Fruits
### Volatile Compounds and Their Biological Characteristic of Major Fruits
The highest OAV values were recorded for ethyl butanoate, nootkatone, linalool and _D,L_-limonene [54]. On the other hand, limonene was the most abundant monoterepne hydrocarbon in both the peel and juice of three major Japanese sour citrus cultivars, Yuzu (_C. junos_ Sieb. ex Tanaka), Sudachi (_C sudachi_ Hort. ex [PERSON]) and Kabosu (_C. sphaerocarpa_ Hort. ex Tanaka), followed by \(\gamma\)-terpinene and \(\beta\)-phellandrene in Yuzu and Sudachi and by myrcene in Kabosu. Mintsulfide was newly identified in juice extracts from Yuzu and Kabosu. Among the oxygenated components, linalool was the most abundant in both the peel and juice of Yuzu and the peel of Sudachi, while both the peel and juice of Kabosu revealed the presence of high quantity of saturated aliphatic aldehydes. Wine lactone and rose oxide were identified in all the extracts, which have not been previously reported to occur in these citrus cultivars. With regard to linalool, the _R_-enantiomer was predominant in Yuzu and the _S_-enantiomer in Sudachi and Kabosu [55]. In other citrus species, such as _C. natsudaidai_ other terpenids are less abundant, but they exert a profound effect on aroma. These include \(\gamma\)-terpinene, \(\beta\)-phellandrene, mycerene, and \(\alpha\)-pinene [20,56]. Mango (_Mangifera indica_ L.) possesses a very attractive flavor characteristic. More than 270 aroma volatile compounds in different mango varieties have been identified in free form [57]. However, application of distillation extraction in combination with active odor value (aroma threshold) technologies exhibits that monoterenes such as \(\alpha\)-pinene, myrecene, \(\alpha\)-phelladrene, \(\sigma\)-3-carene, \(p\)-cymene, limone and terpinolene, esters including ethyl-2-methyl propanoate, ethyl butanoate, as well as (_E,Z_)-2,6-nonadienal, (_E_)-2-nonenal, methyl benzoate, (_E_)-\(\beta\)-ionone, decanal, and 2,5-dimethyl-4-methoxy-3(_2H_)-furanone are the most important compounds contributing to mango flavor [58]. Generally, terpene hydrocarbons are the major class of compounds in New World mangoes, with contents ranging from 16-90%. 3-Carene is the major compound in most New World mango cultivars, with limonene, \(\beta\)-ocimene, myrcene and \(\alpha\)-terpinolene having some importance in some cultivars. Sesquiterpene hydrocarbons may also be present in amounts as high as 10% in some cultivars. There is a large variation in the quality and quantity of alcohols, ketones, and esters in mangoes, especially those of the Old World varieties. Those compounds, together with esters, are responsible for much of the characteristic aroma of Old World mangoes [59]. Terpene hydrocarbons were the major volatiles of nine varieties of Colombian mango, the dominant terpen being \(\delta\)-3-carene (\"Haden\", \"Irwin\", \"Manila\" and \"Tommy Atkins\"), \(a\)-pinene (\"Hilacha\" and \"Vallenato\"), \(a\)-phellandrene (\"Van Dyke\") and terpinolene (\"Yulima\"), while no dominant terpene was found in the fruit of \"Springfield\" [60]. Aroma volatile compounds in the mango fruit have also been reported to be present in the glycosylatedly-bound form [61]. Peach fruit volatiles have been extensively studied, and more than 100 compounds were identified [62; 63; 64], among them, C\({}_{6}\) aldehydes and alcohols offer the green-note aroma, while lactones and esters are responsible for fruity aromas. Esters such as hexyl acetate and (_Z_)-3-hexenyl acetate are considered as key odorants influencing the flavor quality of peach fruit [65]. Changes in aroma-related volatiles have been reported during peach fruit development and postharvest ripening [66]. Aldehydes tend to decline, while esters increase in the fruit, and postharvest treatments, such as low temperature and controlled atmosphere, have been used to investigate postharvest changes in peach aroma quality [8; 67]. To date, more than 200 different volatile compounds have been described in apricots (_Prunus armeniaca_ L.) [68].