Free and Bound Volatile Components of Temperate and Tropical

Chapter 16

Free and Bound Volatile Components of Temperate and Tropical Fruits

Downloaded by UNIV OF MICHIGAN ANN ARBOR on May 20, 2016 | http://pubs.acs.org Publication Date: May 5, 1995 | doi: 10.1021/bk-1995-0596.ch016

D. Chassagne and J. Crouzet Unité de Microbiologie et Biochimie Industrielles, Institut des Sciences de l'Ingenieur, Université de Montpellier II, 34095 Montpellier Cédex 05, France

The distillation extraction and dynamic headspace study of free volatile components present in temperate (apricot) and tropical (mango) fruit cultivars revealed important qualitative and quantitative differences. Terpenic alcohols, linalool, α-terpineol, nerol, nerol derivatives, and linalool oxides, are partially responsible for the floral and fruity flavor of apricot. They are most important in aromatic cultivars. In mango, major differences were observed in terpenic hydrocarbons. Increased concentrations of terpenic hydrocarbons from heat treatment of the purees was considered as indicative of the presence of glucosidically bound components. These non volatile derivatives were found to be 4 to 5 fold more abundant than free volatile compounds in aromatic culivars. Apricot glucosidically bound components, isolated using several chromatographic methods, were identified using H P L C and soft ionization tandem M S . In some cases partial hydrolysis of the saccharide moiety was used for identification. Glucosides were the major glucosidically bound components in apricot and Mango. Glucosides, arabinoglucosides, rutinosides and gentiobiosides represent about 80% of bound compounds in passion fruit. Cyclodextrin bounded stationary phase was employed to separate the diasteroisomers of linalool and α-terpineol in apricot, grape and passion fruit. It is generally recognized that fruit aroma varies qualitative and quantitatively depending on the cultivar, maturity stage, climatic and cultural conditions and the production area for each cultivar. Differences in free and bound compounds from temperate fruits such as apricot as well as tropical fruits such as mango or passion fruits have been reported. In the case of apricot, lactones, identified as being responsible for the background aroma are more important in the cultivars,

0097-6156/95/0596-0182$12.00/0 © 1995 American Chemical Society Rouseff and Leahy; Fruit Flavors ACS Symposium Series; American Chemical Society: Washington, DC, 1995.


16.

CHASSAGNE & CROUZET

Free & Bound Volatile Components of Fruits 183

Polonais and Rouge du Roussillon (1). On the other hand, terpenic alcohols are also considered as contributors of the fruity aroma of apricot (1,2). Lactones, esters and fatty acids are important contributors of mango aroma. However, monoterpene and sesquiterpene compounds responsible of the tropical, turpentine like aroma of this fruit represent 60 to 90 % of total mango volatiles. Important differences concerning the nature and the concentration of these compounds have been pointed out. More recently glycosidically bound volatile compounds, first detected in flowers or in grapes, were identified in several fruits, specifically in; apricot (3,4), mango (5,6) and passion fruit (7,8). The reported results were generally obtained from different cultivars produced in different places, and in some cases the identification of the cultivars was not known. The aim of the present report is the study of free and bound volatile compounds of several specific apricot and mango cultivars all grown at the same location. A t the same time, preliminary results concerning passion fruits of different origins are also given. Free volatile compounds. Apricot Rouge du Roussillon, a very aromatic cultivar grown in the South of France has been extensively studied in our laboratory (2, 9-13). The free volatile compounds were isolated by vacuum distillation and fractionated using silica gel chromatography. The sniffing of the isolated fractions and of the extract obtained after trapping the head-space on Chromosorb 105 indicates that terpinene-4-ol, α-terpineol, nerol geraniol and perhaps 2-phenylethanol are primarily responsible for the fruity aroma of this cultivar. Table I. Terpenic alcohols identified from several apricot cultivars (mg/kg) Cultivars Compounds cis linalool oxide trans linalool oxide linalool 4-terpineol α-terpineol geraniol nerol total

Polonais

Bergeron

Précoce de Tyrinthe

Rouge du Roussillon

0.2 0.8 13.2 0.3 0.5 0.1 0.2 15.3

0.3 0.7 3.8 0.1 0.2 0.1 0.07 5.3

0.2 0.4 1.5 0.2 0.2 0.1 0.1 2.7

0.3 1.0 9.8 0.3 0.5 0.1 0.4 12.4

The quantities of terpenic alcohols isolated from several apricot cultivars apricot obtained from the I N R A orchard ( Manduel France) using dynamic headspace trapping on charcoal-graphite with microwaves desorption are given in Table I. Highest concentrations of total terpenic alcohols were found in highly aromatic cultivars such as Polonais (15.3 mg/kg) and Rouge du Roussillon (12.4 mg/kg) and

Rouseff and Leahy; Fruit Flavors ACS Symposium Series; American Chemical Society: Washington, DC, 1995.

184

FRUIT FLAVORS


lowest in less aromatic cultivars such as Bergeron (5.3 mg/kg), or Précoce de Tyrinthe (2.7 mg/kg). As shown in Table II, major differences in terpene hydrocarbons and terpene alcohol concentrations in the mango cultivar extracts obtained by S D E . The fruit had been obtained from an orchard located near Dakar (Senegal). A s shown in Figure 1, these differences are clearly noticeable in the Chromatograms from extracts obtained from the African mango and Papaya cultivars using the dynamic head-space technique. Table II.

Terpenic compounds identified from several mango cultivars cultivars mango

Governor

Peach

Papaya

Muskat

Amélie

Hydrocarbons (mg/kg) (% of Volatiles)

6.8

3.1

1.1

2.4

1.2

1.3

49

60

20

44

47

15

Alcohols (mg/kg) (% of Volatiles)

0.35

0.14

0.31

0.21

0.05

0.81

2.5

2.4

5.7

3.8

1.9

9.4

compound

The increase of some terpenic compound concentrations observed during heat treatment of mango or apricot puree (10,14) was considered as indicative of the presence of glycosidically bound volatile components in these fruits. More particularly the dramatic increase of α-terpineol during heat treatment of the mango puree cannot be explained by rearrangement reactions of terpenic compounds. The acidic hydrolysis of glycoside derivatives of this alcohol at the p H of the puree (3.9) was considered as more probable. Characterization of glycosidically bound components The presence of glycosidically bound volatile components was established using the rapid analytical technique described by Dimitriadis and Williams (15). Bound compounds are present in all the mango varieties studied, but they are in especially high concentrations in the ungrafted African mango and to a lesser degree in Governor cultivar (6). For the African mango the value obtained for the bound compounds and the ratio between the bound and free forms are comparable to those found for aromatic grape cultivars (15). Shown in Table III are the relative concentrations of free and bound volatile compounds, along with the ratio of bound/free volatiles in several apricot cultivars. Similar results were obtained for passion fruit of different origins (16). The aromatic cultivar, Rouge du Roussillon, contained the highest levels of bound compounds as well as the highest bound/free ratio (5.2). The high bound/free observed for the less aromatic cultivar, Précoce de Tyrinthe, may be attributed to the very low value of free compounds.


CHASSAGNE & CROUZET

Free & Bound Volatile Components of Fruits


16.

Fig. 1 Gas chromatogram of aroma compounds isolated by adsorption on activated charcoalgraphite trap and microwaves desorptionfroma) african mango, b) Peach cv. J &W 30m χ 0.25 mm (i.d.) DB 5 WCOT capillary column. The temperature program was 10 min isothermal at 60°C and thenfrom60 to 250°C at 4°C /min.


185

186

FRUIT FLAVORS

Table III. Free and bound volatile compounds present in several apricot cultivars


cultivar

free

compounds

bound compounds

bound/free

Bergeron

1.9

3.2

1.6

Canino

2.8

3.6

1.3

Rouge du Rousillon

1.5

7.6

5.2

Précoce de Tyrinthe

0.6

3.1

5.4

Important values for bound compounds were found for purple passion fruit of different origins and more particularly in fruits originated from Zimbabwe and Burundi (16). Study of glycosidically bound volatile components The glycosidic fractions of apricot (Rouge du Roussillon), mango ( African mango) and passion fruit (from Zimbabwe) were isolated by adsorption on C 18 reversed-phase (17) or Amberlite X A D 2 (18). Total Hydrolysis. The first step of the study of glycosidically bound components is the identification of the sugar moiety and the volatile compounds released by acidic or enzymatic hydrolysis. The enzymatic method being preferred for the study of the aglycone moiety because of the risks of rearrangement of the terpenes during acidic hydrolysis. In these studies glucose, arabinose and rhamnose were detected by T L C after acid hydrolysis of the terosidic pool of the three fruits. The volatile compounds were identified after enzymatic hydrolysis (hemicellulase R E G 2) of the heterosidic pool. The results obtained for passion fruit are given table I V (19). These results are in good agreement, particularly concerning the C ^ isoprenoids with those reported by Winterhalter (8). The presence of mandelonitrile and benzaldehyde produced by the enzymatic hydrolysis of prunasin and/or sambunigrin (20) should be noted. According to these authors, hydrogen cyanide is released by enzymatic hydrolysis of the cyanogen by emulsin. Mass spectrometry studies. Apricot glycosidic compounds were separated by silica-gel chromatography, gel filtration on Fractogel T S K HW-40 S and preparative over-pressure layer chromatography (OPLC) (12). The use of chemical ionization in negative mode with ammonia as reagent gas (NICI) for the structural study of the isolated fractions indicated that glucosides, (M-H)" m/z 263 (hexyl), 269 (2-phenylethyl), 315( terpene alcohols), 331( linalool oxides or dienediols) were largely present in the fruit. Some arabinoglucosides of monoterpene alcohol ( m/z 447) and of linalool oxides or dienediols ( m/z 463) were also detected.


16. CHASSAGNE & CROUZET


Table I V .

Free & Bound Volatile Components of Fruits

Volatile compounds identified in passion fruit pulp by G C and G C M S after enzymatic hydrolysis (hemicellulase R E G 2) of the heterosidic pool isoeugenol unidentified norisoprenoid hydroxydihydronaphtalene unidentified norisoprenoid unidentified norisoprenoid (B) 4-hydroxy-e-ionol 3-oxo-a-ionol 4-oxo-B-ionol unidentified norisoprenoid (C) unidentified norisoprenoid (D) 3-oxoretro-a-ionol (1) 4-oxoretro-7,8-dihydro-B-ionol 3-oxoretro-a-ionol (2) dehydrovomifoliol vomifoliol

(Z)-3-hexenol 1-hexanol benzaldehyde benzyl alcohol 1-octanol 4-nonanol linalool 2-phenylethanol 4-ethylphenol a-terpineol nerol geraniol 4-allyphenol mandelonitrile eugenol

However it was not possible to distinguish between aglycone isomers. For example each terpene alcohol isomer produces a peak at m/z 315. Tentative identification may be achieved using low energy collisionally activated ( C A D ) fragmentation patterns in NICI tandem mass spectrometry (MS/MS). It was shown (21) that the relative abundance of the ionic species detected in the spectrum was dependent on the nature of the aglycone moiety. Fragmentation rules were established from several synthetic glycosides. The application of the fragmentation rules to the spectra obtained from the O P L C fractions allowed us to tentatively identify; benzyl, 2-phenylethyl, linalyl, α-terpinyl, neryl and geranly glucosides. Linaly and α-terpinyl arabinoglucosides were also tentatively identified. On the other hand, the use of N D as reagent gas in NICI allows the differentiation of isomers such as dienediol and linalool oxide glucosides which both possess a parent ion at m/z 331 and veiy similar low energy C A D spectra. In the presence of N D , the parent ion is shifted to m/z 334 for linalool oxide glucosides possessing four acidic protons whereas for dienediol glucosides ( five acidic protons) a shift of four mass unit is found. Four linalool oxides and four dienediol glucosides were tentatively identified (Table V ) . In the same way a dienediol arabinoglucoside, (M-H)- m/z 463 shifted to m/z 469 (Md7-D)- was detected. Identification by HPLC. H P L C on a C reversed-phase was used for the identification of glucosides when authentic samples are available: linalyl, α-terpinyl, neryl, geranyl, 2-phenylethyl, benzyl and hexyl glucosides and rutinosides (12). Linalyl and α-terpinyl arabinoglucosides were identified after sequential hydrolysis of the glycoside (22). After the action of an arabinase isolated from Aspergillus niger pectinase Reyne et al. (23), observed a decrease in the peak corresponding to the glycoside and the appearance of a peak with the same retention time as the corresponding glucoside. 3

3

1 8


187

188

FRUIT

FLAVORS

Table V . Apricot (cv. Rouge du Roussillon) bound glucosidic compounds identified by NICI mass spectrometry using N H and N D as reagent gas 3

number of

parent ions


3

fragmentation

suggested structure

compounds

334

2M

4

335 335 469

2M 1M -

linalyl oxide glucoside dienediol glucoside dienediol glucoside dienediol arabino glucoside

(M-H)"

(M-D)

331 331 331 463

+

2 2 1

These results, are in good agreement with the preliminary report of Salles et al. (11). They demonstrated that about 90% of the glycosidically bound volatile compounds in apricot were glucosides. The remaining 10%, are disaccharidic derivatives. However, in this group, only arabinoglucosides were detected. Dissacharidic compounds are predominant in other fruits such as aromatic grapes. Between 32 to 58 % arabinosylglucosides, 28 to 46% apiosylglucosides, 6 to 13 % rhamnosylglucosides (rutinosides) and only 4 to 9 % glucosides have been reported by Bayonove et al. (24). Preliminary results obtained for glycosidically bound volatile compounds in passion fruit reveal that there are about 22% glucosides, 12% arabinosylglucosides, 39 % rutinosides and 27 % gentiobiosides present (19). Among these compounds, 2-phenylethyl, linalyl, α-terpinyl, geranyl and neryl glucosides and rutinosides and benzyl alcohol rutinoside have been identified by analytical O P L C and H P L C from the fractions isolated by preparative O P L C . When a cyclodextrin bounded-phase (Cyclobond I) was used, the two diastereoisomers resulting of the binding of tertiary monoterpene alcohols to the glucoside unit are separated (13). These results show that linalool is bound as a glucoside, arabinoglucoside or rutinoside and is present at 85 % as (S)-(+) isomer in apricot and passion fruit. More than 95 % of glycosidically bound linalool in grapes, is found as the (S) (+) isomer. In apricot, 70 % of the (S)-(-)isomer and 30% of the (R)-(+) isomer of α-terpineol are bound to a glucose unit. Conclusion Important qualitative and quantitative differences were found for free terpenic compounds present in temperate (apricot) and tropical (mango) fruits according to the nature of the cultivar for the same origin. The glycosidically bound volatile compounds are about 4 to 5 fold more abundant than free compounds in aromatic cultivars. The determination of the structure of isolated heterosidic fractions by M S , M S - M S and H P L C shows that glucosides are the major glycosidically bound components in apricot (90%) whereas in passion fruit these compounds represent only 22% of the bound compounds.


16.

CHASSAGNE & CROUZET

Free & Bound Volatile Components of Fruits 189

The ratio of the two diastereoisomers of linalyl and α-terpenyl glycosides present in apricot passion fruit or grapes varies according to the nature of the fruit.

Literature Cited


1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

11. 12. 13. 14. 15. 16.

17. 18. 19. 20. 21. 22. 23. 24.

Guichard, E. and Souty, M. Z. Lebensm Unters. Forsch. 1988, 186, 301-307. Chairote, G., Rodriguez, F. and Crouzet, J. J. Food Sci. 1981, 46, 1898-1901. Krammer, G.M., Winterhalter, P.M., Schwab, M., and Schreier, P.J.Agric. Food Chem. 1991, 39, 778-781. Salles, C., Jallages, J.C., Fournier, F.. Tabet, J.C., Crouzet, J.C.J. Agric. Food Chem. 1991, 39, 1979-1983 Adedeji, J., Hartman, T.G., Lech,J.,and Ho, C.T. J. Agric. Food Chem. 1992, 40, 659-661. Koulibaly, Α., Sakho, M., and Crouzet, J. Lebensm.-Wiss. u.-Technol. 1992, 25, 374-379. Engel, K.H. and Tressl, R. J. Agric. Food Chem. 1983, 31, 998-1002. Winterhalter, P. J. Agric. Food Chem. 1990, 38, 452-455. Rodriguez, F., Seek, S., and Crouzet, J. Lebensm.-Wiss. u. -Technol. 1980, 13, 152-1550. Crouzet, J., Chairote, G., Rodriguez, F., Seek, S. In Instrumental Analysis of Foods and Beverages: Recent Progress. Charalambous, G. and Ingett, G., Eds.; Academic Press, New York:1983:pp 119-135. Salles, C., Essaied, H., Chalier, P., Jallagas, J.C., and Crouzet, J.C. In Bioflavor'87. Schreier, P., Ed.; W. de Gruyter: Berlin, 1988: pp. 145-160. Salles, C., Jallgeas, J.C., and Crouzet, J. J. Chromatogr. 1990, 522, 255-265. Salles, C., Jallgeas, J.C., and Crouzet, J. J. Essent.OilRes. 1993, 5, 381-390. Sakho, M., Crouzet, J. and Seck, S. Lebensm.-Wiss.u.-Technol. 1985, 18, 89-93. Dimitriadis, E. and Williams, P. J. Am. J. Vitic. Enol. 1984, 35, 66-71. Chalier, P., Koulibaly, A.A., Fontvielle, M.J., and Crouzet, J. In Proceedings of Symposium of International Federation of Fruit Juice Producers. Paris. Kûnddig Druck, AG: Zug, 1990: pp. 49-354. Williams, P.J., Strauss, C.R., Wilson, B. and Massy-Westropp, R.A. Phytochemistry, 1982, 21, 2013-2020. Gunata, Y.Z., Bayonave, C.L., Baumes, R.L., And Cordonnier, R.E. J. Chromatogr. 1985, 331, 83-90. Chassagne, D. unpublished data. Spencer, K.C. and Seigler, D.S. J. Agric. Food Chem. 1983, 31, 794-796. Cole, R.B., Tabet, J.C., Salles, C., Jallageas, J.C. and Crouzet, J. Rapid Commun. Mass Spectrom. 1989, 3, 59-61. Gunata, Z., Bitteur, S., Brillouet, J.M., Bayonove, C. and Cordonnier, R. Carbohydr. Res. 1988, 184, 139-149. Reyne, V. Salles, C., and Crouzet, J. In Food Science and Human Nutrition. Charalambous, G., Ed. Elsevier Sci. Pub.: Amsterdam, 1992: pp. 99-114. Voiin, S., Baumes, R., Sapis, J.C., and Bayonove, C. J. Chromatogr. 1992, 595, 269-281.

RECEIVED January 25, 1995


Free and Bound Volatile Components of Temperate and Tropical

Recommend Documents