Passion fruit flavor compounds

Figure 5 Extraction of passion fruit flavor compounds using headspace SPME (PDMS/ DVB fiber).

B. Weber, B. Maas and A. Mosandl, Stereoisomeric flavor compounds. 72. Stereoisomeric distribution of some cliiral sulfur containing trace components of yellow passion fruits , ]. Agric. Food Chem. 43 2438-2441 (1995). 

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. 

C,H,60S, Mr 160.27 discovered and synthesized in 1976 as the typical flavor compound of the yellow passion fruit (Passiflora edulis) (see fruit flavors). Racemic cis-Zira/is-mixture 1 10, oil with an exotic fruity odor, bp. 85 -86 °C (1.6 kPa). Synthesis and sensory evaluation of the four stereoisomers demonstrated that the (-F)-(2S,4/f)-form was the compound with the typical passion fruit character, olfactory threshold in water 2 jmb, [alo" -f56.1 (CCI4). According to chiral analysis, however, the passion fruit contains the (4S)-epimer pair with an untypical, sulfurous, herby-green or, respectively flowery odor (-)-(2R,4S), [a]g -56.1 , and (-)-(2S,4S), (a]g -117.6°. For biosynthesis, see Ut.. ... 

Although the number of aroma compounds derived from acyclic carotenoids is much inferior to that of the mono- and bicyclic compounds, some of them can also be considered as breakdown products from genuine mono-, sesqui- and diterpenoids. The importance of the aliphatic isoprenoids (282) to (291) in the formation of total flavors of certain foodstuffs is not less than that of the cyclic compounds, the three methyl ketones (282), (287) and (290) which are related to the main tomato pigment lycopene were observed in tomato flavor (75). The hexahydro derivative (291) from coffee (595), jasmine oil (722) and green tea 438) is perceived as flowery and warm and can be considered as an oxidative biodegradation product of phytol and phyta-diene. 6-Methyl-3,5-heptadien-2-one (283), with a grassy and cinnamonlike aroma 438) [detected in tomato 668), the essential oil of Hama-metis leaves 383), Ceylon tea (722) and passion fruit (777)], and pseudo-ionone (288) [also isolated from passion fruit (777)] are believed to be formed from two different dehydrolycopenes. Compounds other than carotenoids, such as solanesol or squalene, can also be considered... 

Dihydro-1,1,6-trimethyl naphthalene (Table 3.59) can be formed by a degradation of neoxanthin and other carotinoids during the storage of wine. It smells like kerosene (threshold 20pg/kg, wine). It is thought that this odorant contributes considerably to the typical aroma of white wine that was stored for a long period in the bottle. The compound may cause an off-flavor in pasteurized passion fruit juice. 

Figures 5 through 7 show a few applications from our laboratory, demonstrating the importance of SPME for the extraction and analysis of flavor compounds from a variety of foods. Figure 5 illustrates headspace SPME concentration of flavor compounds from several species of passion fruit (Passiflora spp.). The various organoleptic properties of the three varieties of fruit are nicely reproduced in the resulting flavor profiles, i.e. the SPME technique can reliably be used to characterize fruits and differentiate among varieties.

The tropical category is one of the most important areas for new discoveries of key impact flavor compounds. Analyses of passion fruit and durian flavors have produced identifications of many potent sulfur aroma compounds (18). Among these is fropathiane, 2-methyl-4-propyl-l,3-oxathiane, which has an odor threshold of 3 ppb (15). For pineapple, 2-propenyl hexanoate (allyl caproate) exhibits a typical pineapple character (11) however, Furaneol, ethyl 3-methyl-thiopropionate, and ethyl-2-methylbutyrate are important supporting character impact compounds (31). The latter ester contributes the background apple note to pineapple flavor. Another character impact compound, allyl 3-cyclohexyl-... 

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