Aroma passion fruit

Cofermentation with two or more strains has recently been exploited to enhance the aromatic profile of Sauvignon Blanc wines, in which a non-volatile 5-cysteinylated precursor (3-(hexan-1 -ol)-L-cysteine) is first hydrolysed by a carbon-sulfur lyase and subsequently esterifled by alcohol acetyltransferase (Sect. 8D.5.2). Strains of Saccharomyces cerevisiae vary in ability to carry out the two reactions (Dubourdieu et al. 2006 Swiegers and Pretorius 2007). Cofermentation with two strains, one having higher hydrolytic function (release of 3-MH) and the other higher esterification activity, substantially enhanced formation of 3-MHA, thereby increasing the passion-fruit aroma when compared to monoculture wines. The authors showed that interaction between the two strains produced more 3-MH and 3-MHA... 

Fruits have received extensive study one example is that of the passion fruit volatiles. Another fruit in which sulfur volatiles play an aroma role is musk-melon (Cucumis melo cv. Makdimon). A musky overtone is provided by 3-(methylthio)propanal ( stale ) and 5 -(methylthio)-butanoate ( pine, earthy )... 

Possible differences are also well illustrated by 3-thio- and 3-methyl-thiohex-anols and their esters (Table 1). Among these compounds, there is a tendency for the (R) enantiomers to have a typical, fruity aroma. However, for 3-methylthiohexanol (an aroma component of yellow passion fruit) this situation is reversed the (S) enantiomer had the characteristic fruity aroma ( exotisch, fruchtig ).52 For the separation of enantiomers of odorous compounds, enan-tioselective GLC with chiral stationary phases, and MGDC techniques using a conventional capillary column and an enantioselective column are commonly used.53... 

NT529 Demole, E., P. Enggist, M. Winter, et al. Megastigma 5,8 dien-4 One, an aroma constituent of the yellow passion fruit and Virginia tobacco. Helv Chim Acta 1979 62 67. 

Owing to their unique and delicate flavour, species of the genus Passiflora have been the subject of intensive research on their volatile constituents [13]. The purple passion fruit (Passiflora edulis Sims) is a tropical fruit native to Brazil but is now grown in most tropical and subtropical countries [50]. Purple passion fruit is cultivated in Australia, India, Sri Lanka, New Zealand, and South Africa [48]. Yellow passion fruit (Passiflora edulis t flavicarpa) is one of the most popular and best known tropical fruits, having a floral, estery aroma with an exotic tropical sulfury note [62]. Yellow passion fruit is cultivated in Brazil, Hawaii, Fiji, and Taiwan [48]. Because of its more desirable flavour, the purple passion fruit is preferred for consumption as fresh fruit, whereas the yellow passion fruit is considered more suitable for processing [28]. 

Later, the chemical characterisation of the volatiles from yellow passion fruit essence and from the juice of the fruit was done by GC-MS and GC-olfactom-etry (GC-O) [27]. Esters were the components found in the largest concentrations in passion fruit juice and essence extracted with methylene chloride. Analysis by GC-O yielded a total of 66 components which appeared to contribute to the aroma of passion fruit juice and its aqueous essence. Forty-eight compounds were identified in the pulp of Brazilian yellow passion fruits (Passiflora edulis f. flavicarpa) [48]. The predominant volatile compounds belonged to the classes of esters (59%), aldehydes (15%), ketones (11%), and alcohols (6%). 

Werkoff, P., Giintert, M., Krammer, K Sommer, H., and Kaulen, J. 1998. Vacuum headspace method in aroma research Flavor chemistry of yellow passion fruits. J. Agric. Food Chem. 46 1076-1093. 

Methods for the capillary gas chromatographic separation of optical isomers of chiral compounds after formation of diastereoisomeric derivatives were developed. Analytical aspects of the GC-separation of diastereoisomeric esters and urethanes derived from chiral secondary alcohols, 2-, 3-, 4- and 5-hydroxy-acid esters, and the corresponding jf- and -lactones were investigated. The methods were used to follow the formation of optically active compounds during microbiological processes, such as reduction of keto-precursors and asymmetric hydrolysis of racemic acetates on a micro-scale. The enantiomeric composition of chiral aroma constituents in tropical fruits, such as passion fruit, mango and pineapple, was determined and possible pathways for their biosynthesis were formulated. 

Tropical fruits, such us passion fruits, mangos or pineapples, contain many chiral aroma constituents. So far, their enantiomeric composition is unknown, because the conventional method, measuring optical rotation, can not be applied to these components, which can be isolated from the fruits only in small amounts. The new techniques of capillary GC analysis of diastereoisomeric derivatives made it possible to characterize the enantiomeric composition of several chiral trace constituents. These results may be used to gain insight into the biogenesis of aroma components or to control natural aroma concentrates. 

Odd-numbered secondary alcohols (pentanol-2, hepta-nol-2, nonanol-2) are contained as aroma components in yellow (Passiflora edulis f. flavicarpa) and purple (Pas-siflora edulis simsl passion fruits the corresponding esters however are typical constituents only of the purple variety (2 3). The capillary GC investigation of the enantiomeric composition of these chiral components revealed interesting aspects of their biogenesis. 

As shown in Figure 7 ethyl 3-hydroxyhexanoate, isolated from purple passion fruit possessed the (R)-configuration, comparable to the hydroxyacid ester obtained by the reduction with baker s yeast. In contrary to that methyl 3-hydroxyhexanoate, which was isolated from aroma extracts of pineapple, consisted of the (S)-enantiomer (91 %). ... 

Tominaga, T, Dubourdieu, D. (2000). Identification of cysteinylated aroma precursors of some volatil thiols in Passion fruit juice. J. Agric. Food Chem., 48, 2874-2876. 

The Centritherm-Evaporator (27) is very popular for the concentration of passion fruit juice. This is a one-stage rotary thin film evaporator which can be fitted with or without aroma recovery. Originally developed by Alfa Laval for concentrating sensitive products in the pharmaceutical industry, this machine is now sold and serviced by FLAVOURTECH Pty. Ltd (27). For the very efficient recovery of the aroma FLA-VOURTECH can also offer a so-called Spinning Cone Column which has been successfully applied for the recovery of difficult-to-recover aromas such as coffee aroma. 

In 1976 Winter et al. (22) identified 3-methylthio-hexanol and a mixture of (Z)- and (E)-2-methyl-1,3-oxa-thiane in yellow passion fruit. 3-Methylthiohexanol possesses a green fatty and sulfury note and imparts the character of fresh fruit to the juice of passion fruits. The oxathianes were described as key compounds for the typical aroma of passion fruit and the (Z)-isomer had a stronger flavor. Pickenhagen and Bronner-Schindler (23) synthesized the enantiomers of (+)- and (-)-(Z)-2-methyl-... 

Laboissiere et al. (2007) showed that high-pressure processing (300 MPa, 5 min, 25°C) could be used to preserve yellow passion fruit pulp, yielding a ready-to-drink juice with improved sensory quality, free from cooked and artificial flavor attributes, as compared to commercial juices. High-pressure treatment did not cause any significant modifications in compounds responsible for aroma, flavor, and consistency. 

Thiazoles occur in nature as substances with an aromatic odour, for instance 4-methyl-5-vinylthiazole in the aroma of cocoa beans and passion fruit, 2-isobutylthiazole in tomatoes and 2-acetylthiazole in the aroma of roasted meat. 

Sulfur compounds in the thiol family (or mercap-tans) are generally held responsible for olfactory defects (Section 8.2.2). However, their major contribution to the aromas of certain fruits and aromatic plants has been clearly estabhshed. Thus, specific thiols are involved in the characteristic aromas of fruits such as blackcurrant (Rigaud et al., 1986), grapefruit (Demole et al., 1982), passion fruit (Engel and Tressel, 1991) and guava (Idstein and Schreier, 1985 Bassols and Demole, 1994). Two mercaptans, ethyl-3-mercaptopropion-ate and ethyl-2-mercaptopropionate, have been identifled as components in the aroma of Vitis labrusca grapes (variety Concord) (Kolor, 1983 Winter et al, 1990). 

The aroma of 3-mercaptohexanol is redolent of grapefruit and passion fruit, in which it has also been identified. The perception threshold is on the order of 60 ng/1. It is always present in Sauvignon Blanc wine at concentrations of several hundred ng/1, and there may be as much as a few... 

CmH.sOj, Mr 180.25, mp. 69-71 °C, [a] -119.9 (CHCI3). A norisoprenoid with hay-like odor arising from carotinoid degradation the (/ )-form occurs in the aromas of tea, tobacco, currants, passion fruit, tomatoes, etc.. ... 

Passion fruit Red Rf. (Passiflora edulis) . The flowery-fruity flavor is due in particular to (Z)-3-hexenyl esters, (Z)-3-octenyl acetate, citronellyl and geranyl acetate. Yellow P.f. (P. edulis flavicarpa). 2-Methy 1-4-propyl-1,3-oxathiane, 3-mercapto-l-hexanol (CjHuOS, Mr 134.24, CAS [51755-83-0]) and the corresponding esters are mainly responsible for the exotic-fruity flavor. In both sorts about 30 Cu-noriso-prenoids, including fl ionone, )3- damascenone and edulane (2,5,5,8a-tetramethyl-l-benzopyran) make major contributions to the aroma. 

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