Peach lactones

CIC The typical lactony note is produced by 4-decanolide. The flavour industry since years uses mainly the 4-undecanolide, the so called peach lactone . The lactone has to be balanced with fmity esters like 3-methyl butyl acetate, the floral-fmity note of linalool and some green notes like (E)-2-hexenal. 

Lactones (19) and (2C1) both have peach odours and are used in perfumes. Suggest syntheses. 

Some representatives of y-lactones are y-valerolactone 150, y-decalactone 151 with peach-like flavour, (Z)-6-dodecen-4-olide 152, 3-methyl-4-octanolide (whiskey lactone) 153 and 3-hydroxy-4,5-dimethyl-2(51T)-furanone (sotolone) 154 (Structure 4.46), found in fenugreek, coffee and sake [1-4, 21-23, 62]. 

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,... 

Approximately 75 volatile compounds have been identified in juices prepared from plums Prunus domestica) [35]. Lactones from Ce to C12 are the major class of compound in plums [78]. The distribution of plum lactones differs from that found in peaches in that the C12 y-lactones are found in higher concentrations than the corresponding Cio y-lactones and d-decalactone (Fig. 7.2) [78]. GC sniffing has uncovered benzaldehyde, linalool, ethyl nonanoate, methyl cin-namate, y-decalactone and d-decalactone as volatile compounds contributing to plum juice aroma (Table 7.2, Figs. 7.1, 7.2, 7.4, 7.5) [35]. 

Owing to their pleasant odours many y-lactones and d-lactones are known to be Important flavour compounds of fruits and contribute essentially to the characteristic and distinctive notes of strawberries, peaches, apricots and many other fruits [24]. Chiral aroma compounds from fruits and other natural sources are characterised by origin-specific enantiomeric ratios, as their biogenetic pathways normally are catalysed by enzymes. 

The closely related 5-decanolide (5-decalactone), not only found in many fruits but also found in dairy products, exhibits a creamy-coconut, peach-like aroma [49] and can be synthesised from the corresponding a,(3-unsaturated lactone 2-decen-5-olide found in concentrations of up to 80% in Massoi bark oil using basidiomycetes or baker s yeast [229]. After about 16 h of fermentation, 1.2 g 5-decanolide was obtained. At the same time, the minor lactone in... 

Bruce, G. W. J. Fleet, A. CJirdhar, M. Haraldsson, J. M. Peach, and D. I. Watkin, Retention and apparent inversion during azide displacement of avtriflates of 1,5-lactones, Tetrahedron 46 19 (1990). 

Higher molecular weight lactones, such as y-decalactone, 6-dodecalactone, y-jasmolactone, occur in fruit (peach and apricot aromas) but have been not found in wine, at least in very small traces by gas chromatography/ mass spectrometry (GC-MS). If they are detected in higher quantities, then these lactones were undoubtedly added illegally, a case for prosecution (10MI3,07MI27). 

Numerous y- and 8-lactones were identified in Tokaji aszu grapes (Miklosy and Kerenyi, 2004 Miklosy et al., 2004). The odor notes of the y-lactones were described as resin- and caramel-like, roasted, or honey, while the 8-lactones exhibited characteristic notes of coconut, chocolate, and peach. The same lactones had been identified earlier from botrytized wines but not from normal wines (Schreier et al., 1976). Lactones are mostly found in oxidatively aged wines but seem to develop in fruit due to the oxidizing effect of B. cinerea, water loss, or Maillard reactions (Miklosy et al., 2004). 

CHROMATOGRAMS OF PEACH VOLATILES WITH LACTONES IDENTIFIED... 

Lactones are cyclic compounds formed through the intramolecular esterification of a hydroxy fatty acid. 7-Lactones and 8-lactones, with fivesided and six-sided rings, respectively have been found in cheese (Jolly and Kosikowski, 1975 Wong et al., 1975 Collins et al., 2004). The origin of the precursor hydroxy fatty acids has been ascribed to a 8-oxidation system in the mammary gland of ruminants (see Fox et al., 2000), the reduction of keto acids (Wong et al., 1975) and/or the action of lipoxygenases and other enzymes present in members of the rumen microflora (Dufosse et al., 1994). Lactones have low flavor thresholds and while their aromas are not specifically cheese-like (their aromas have been described variously as peach, apricot and coconut ), they may contribute to the overall flavor of cheese (see Collins et al., 2004). 

Decalactone FEMA No. 2360 4-Hydroxydecanoic Acid Lactone 170.25/C10Hi8O2/ CH3(CH2)5CHCH2CH2C=0 1 o colorless to pale yel liq/ fruity, peach s—prop glycol veg oils ins—water/ 281° 1 mL in 1 mL 95% ale... 

Hydroxyundecanoic acid lactone) (aliphatic lactone) Prunus persica (peach) (Rosaceae) [fruit] ... 

Decalactone Ricinolic acid, cor-rolic acid, Massoia lactone or 11-hydroxy hexadecanoic acid Candida species, Clador-sporium sua-volens, baker s yeast Peach, buttery... 

In Group 9 various organic acids like lactic acid (Flavis 08.004, FEMA 2611), pyruvic acid (Flavis 08.019, FEMA 2970) and succinic acid (Flavis 08.024, registered in Food Chemical Codex) together with various diesters are found. Beside some diols, numerous lactones such as y-decalactone (Flavis 10.017, FEMA 2360) with peach-like notes and 8-decalactone (Flavis 10.007, FEMA 2361) with a sweet coconut-like profile are represented. 

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. 

These terpene notes are supported by (Z)-3-hexenol, (E)-2-hexenal, (E)-2-hexenol with their fresh, green character. Gamma- and delta-lactones (4-decanolide, 5-decan-olide, 4-dodecanolide, 5-dodecanolide-(Z)-7-decen-5-olide) impart the sweet, creamy, buttery, peach and apricot character. 2,5-Dimethyl-4-hydroxy-furan-3(2H)-one and 2,5-dimethyl-4-methoxy-furan-3(2H)-one are responsible for the sweet creamy fruity body. A bouquet of esters imparts the overall fruity character (mainly esters of ethyl-, (Z)-3-hexenyl and butyl alcohol with acetic-, butanoic-, 2-butenoic, 3-hydroxybutanoic- and hexanoic acid). 

Chiral y-lactones are important compounds of many fruits and give strawberries, peaches, apricots and many other fruits their characteristic and distinctive notes [74]. Albrecht and Tressl [75] investigated the biogenetic sequence of y-decalactone. These results indicate that (E)-3,4-epoxydecanoic acid, formed from (E)-3-decenoyl-CoA, an intermediate of the P-oxidation of linoleic acid, is the genuine precursor in the biosynthesis of y-decalactone. 

Peaches, apricots and greengages contain y(5)-lactones with characteristic enantiomeric ratios in favour of R-configured lactones, proving reliable indicators of genuineness during all stages of fruit processing (Fig. 6.31). 

Lactones are cyclic compounds with relatively high boiling points and an ester functional group. They have the characteristic ester notes fruity, oily, and sweet. y-Undecalactone, with a peach-hke aroma, has a boiling point of 297°C. 

Candida strains convert ricinoleic acid into If-decalactone, which displays the fatty, fruity aroma typical of peaches. Ricinoleic acid (12-hydroxy octadec-9-enoic acid) is the major fatty acid in castor oil (approx. 80 %). The yeast can lipolyze castor oil glycerides and the liberated ricinoleic acid is subsequently metabolized via d-oxidation and eventually converted to 4-hydroxy-decanoic acid (Figure 5). Recently a European patent has been filed (20) essentially covering the same procedure. Shake culture fermentations were carried out on 100 ml scale for one week. The 4-hydroxydecanoic acid formed was converted to )f-decalactone by boiling the crude, acidified (pH 1.5) fermentation broth for a period of 10 minutes. The lactone was isolated via solvent extraction and a yield of some 5 g/1 was obtained. The same lactone was detected as the major volatile component formed when the yeast, Sporobolomyces odorus was grown in standard culture medium (21). Although the culture medium displayed an intense fruity, typical peach-like odor, the concentration of y-decalactone amounted to no more than 0.5 mg/1. 

Ceratocystis sp. Banana, pear, peach, plum Alcohols, esters, monoterpene alcohols, lactones... 

When the 2-alkylcyclopentanones are subjected to the Bayer-Villiger reaction, the resultant lactones are found to have sweet, buttery, peach and coconut odours. These are useful in floral fragrances, but their major use is as butter flavour in margarines. 

Spadone et al. (1990) also identified aliphatic unsaturated aldehydes, long-chain 2-alkanones, lactones and esters which are only present in green coffee and would give the beans the characteristic soapy, fatty and fruity (coconut, peach, apricot) notes. They were the first authors to find (3-damascenone (Section 5,D.38) in raw coffee, a compound that resists roasting and contributes highly to the tea-like and fruity flavor of the beverage,... 

Sn-beta, combined with hydrogen peroxide as oxidant, has the potential to substitute classical oxidants, for example peracids, in BV oxidations. As an example, the oxidation of delfone (2 pentylcyclopentanone) to d-decalactone (tetrahydro-6-pentyl-2H-pyran-2-one) is currently achieved using the corrosive peracetic acid. The resultant lactones have a creamy coconut-and peach-like aroma and are important flavor constituents of many types of fruit, and cheese and other dairy products. The lactones are also used in fragrances the two enantiomers have different aromas. Sn-beta was tested for this BV transformation in a stirred reactor. The desired lactone product was obtained in 86% yield in the presence of the Sn-beta catalyst. (302) This result demonstrated clearly that the combination of Sn-beta and hydrogen peroxide is an environmentally friendly alternative to the commonly used organic peracids, even in asymmetric synthesis. Instead of a stoichiometric amount of carboxyHc acid waste, water is produced as a side product from the oxidant. 

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... 

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