Aroma peach

There are two methods available for aroma recovery. In one method, a portion of the water is stripped from the juice prior to concentration and fractionally distilled to recover a concentrated aqueous essence solution. Apple juice requires 10% water removal, peach 40%, and Concord grape 25—30% to remove volatile flavor as an essence. Fractional distillation affords an aqueous essence flavor solution of 100—200-fold strength, which means the essence is 100 to 200 times more concentrated in flavor than the starting juice. A second method of essence recovery is to condensate the volatiles from the last effect of the evaporator they are enriched in volatile flavor components (18). 

R)- -Decalactone contributes much of the characteristic taste and aroma of peach and many other flavours. Chemically synthesised T -decalactone has been cheaply available for a long time, but the consumer demand for naturally flavoured food and beverages that arose in the mid 1980s created a strong demand for the (RJ-lf -decalactone isomer as a natural food flavour molecule. This definition of natural grade required its production by entirely enzyme-based steps. In turn this led to the development of a number of biotransformation processes to make natural f -decalactone. 

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. 

Decanolide (y-decalactone), which imparts a powerful fruity, especially peach-like aroma has a market volume of several hundred tons per year. In the early 1980s, natural 4-decanolide was an extremely expensive, rare natural flavour (price in excess of US 10,000 per kilogram). The subsequent introduction and optimisation of its biotechnological production has resulted in a steady decrease of the price to approximately US 300 per kilogram and an increase of the market volume to several tons per year [8]. 

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... 

In addition, y-nonalactone 4, (S)-(-)- and (R)-(+)-4-pentylbutan-4-olide, shows weak to strong sweet coconut notes, as well as peach and apricot aromas. 

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). 

White ports vary in style, depending on the duration of maturation. When aged in oak barrels for many years, the wine acquires a golden color that resembles a very old tawny wine and picks up a nutty character from the wood (Mayson, 2003). White ports destined to be drunk young are crisp, with an intense bouquet that combines aromas of melons and peach, with hints of citrus fruit, camomile, and lemon balm flowers. In contrast, white ports aged in wood present a complex aroma of tropical fruits, such as pineapple and banana, with a touch of almond and vanilla. 

The main difference between botrytized wines and other nonfortified sweet wines, for example, late-harvest wines, icewines (eiswein), or straw wines, is the extreme range and richness of the aroma compounds produced by Botrytis. Marked differences also exist in some other components (e.g., glycerol, acid composition), due to the microbial activity. According to the descriptors most often applied to these wines, they are characterized by peach, apricot, pear, quince, raisin, and honey flavors, combined with distinctive "botrytis or roti aspects. Another typical feature of botrytized wines is their high acid contents. These prevent them from appearing cloying, even if the sugar content is commonly over 200 g/1. 

The uses of vanillin in international perfumery are many. In aldehydic perfumes, vanillin provides the powdery impression given by the background smell, usually up to 2% in the perfume concentrate. In fruity notes, vanillin enhances the various fruity constituents (0.1—0.5% in pears up to 2% in peaches) for instance, a peach note is not fully peach without vanillin. When vanillin is combined with some floral notes, such as heliotrope and orchid, which actually contain strong vanilla impressions, amounts of 2—5% are possible. However, with notes such as rose, orange flower, and jonquil, the addition of 0.1—2% vanillin can bring warmth and elegance. In woody families such as fougiire and chypre, and also in spicy perfumes, the harsh impression also needs the fine, smooth aroma provided by vanillin traces. 

A peach coloured oil with a delicate nutty aroma. Emollient and highly nourishing it is particularly suited to dry and mature skins. It is unusual in that it is comparatively high in the unsaturated fatty acids oleic acid (55-67%), pal-mitoleic acid (18-25%), palmitic acid (7.0-9.5%), stearic acid (2.0-5.5%) and myristic acid (0.6-1.6%). It has good keeping properties, as it is quite resistant to oxidation. There are no reported irritation or allergy reactions in skin testing. 

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). 

The development of modern analytical methods has permitted the examination of volatiles from fresh fruit to determine when to pick the fruit. It is the usual concept that fruits are at their best when picked "tree-ripe". However, in extreme cases, as with bananas and pears, these fruits must be picked when hard and green and be permitted to soften and ripen off the tree. If these fruits are permitted to ripen on the tree, they become mealy and unacceptable. Some fruit, like strawberries and peaches, are of best quality when left to ripen on the plants. Apples have been shown to have the best aroma if picked almost ripe and develop the most aroma about a week or two after picking. 

A peach still attached to the tree was selected for analysis on the basis of its possessing a full, rich, at-the-peak-of-ripeness aroma. Taking care not to bruise the fruit, the peach... 

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. 

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. 

Ci0Hi8O2, Mr 170.25, bp3 Pa 117-120°C, r/f 5 0.9540, ng 1.4537, is a flavor constituent of many types of fruit, cheese, and other dairy products. It is a colorless, viscous liquid with a creamy-coconut, peach-like aroma. 

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