Revista CENIC. Ciencias Químicas ISSN: 1015-8553 [email protected] Centro Nacional de Investigaciones Científicas Cuba

Quijano, Clara Elizabeth; Pino, Jorge A. Changes in volatile constituents during the ripening of cocona ( sessiliflorum Dunal) Revista CENIC. Ciencias Químicas, vol. 37, núm. 3, 2006, pp. 133-136 Centro Nacional de Investigaciones Científicas La Habana, Cuba

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Changes in volatile constituents during the ripening of cocona (Solanum sessiliflorum Dunal) fruit

✤ Clara Elizabeth Quijano and Jorge A. Pino.*

Universidad de los Andes, Facultad de Ciencias, Dpto. de Química, Cra. 1a Este No. 18-A-10 Edif. (Q-826), Bogotá, Colombia. *Instituto de Investigaciones para la Industria Alimenticia, Carretera al Guatao km 3½, La Habana, Código Postal 19200, Cuba. E-mail: [email protected]

Recibido: 14 de mayo de 2005. Aceptado: 10 de febrero de 2006.

Palabras clave: cocona, Solanum sessiliflorum, maduración, compuestos volátiles, CG-EM. Key words: cocona, Solanum sessiliflorum, maturation, volatile compounds, GC-MS.

RESUMEN. La cocona (Solanum sessiliflorum Dunal) es un arbusto nativo de la INTRODUCTION región del Alto Orinoco en la cuenca del Amazonas, el cultivo se ha extendido y Solanum sessiliflorum Dunal is a tecnificado debido a su fruto comestible, el cual ha comenzado a comercializar- shrub native from the upper Orinoco se, es muy apetecido por su exquisito sabor y aroma. En este estudio se evaluó region of the Amazon basin, previ- la composición de los constituyentes volátiles en la pulpa de cocona durante la maduración de la fruta. Tres estados de madurez fueron estudiados: verde, pintón ously cultivated by natives because y maduro. Los compuestos volátiles se aislaron por extracción líquido-líquido con of its edible , which are rarely 1,2 pentano-diclorometano 1 : 1 (v/v) en forma continua y se analizaron por cromato- used nowadays. It is commonly grafía de gases con detector de llama de hidrógeno y por cromatografía de gases named cocona, coconilla or naran- acoplada a espectrometría de masas. Un total de 76 compuestos se identificaron jilla in Colombia, and cibiu in Bra- en la fruta de ellos, 38 constituyentes en estado verde, 67 en estado pintón y 66 zil. en estado maduro, la mayoría reportados por primera vez en esta fruta. Durante The cocona is a highly la maduración, se observó un incremento en la concentración de los ésteres branched, herbaceous shrub which y alcoholes, así como una disminución respecto a los compuestos carbonílicos. reaches a height up to 2 m. It has a Los constituyentes mayoritarios son similares en los tres estados de madura- downy stem, densely white-hairy ción, pero el salicilato de metilo es el compuesto que presentó la mayor concen- α twigs, and ovate leaves, which are tración en el estado de madurez junto con el -terpineol y en menor proporción el oblique at the base, scalloped on the (Z)-3-hexenol, mientras que los aldehídos como el (Z)-3-hexenal, (Z)-2-hexenal, margins, downy on the upper sur- (E)-2-hexenal y hexanal disminuyeron su contenido con la maduración. face, prominently veined beneath. The leaves are about 45 cm long and ABSTRACT. Cocona (Solanum sessiliflorum Dunal) is a shrub native from the 38 cm wide. The flowers, in clusters upper Orinoco region of the Amazon basin, recently his culture has extended of 2 or more in the leaf axils, are and technified due to its edible fruits, which has begun to commercialize itself 2.5 cm wide, with 5 pale greenish-yel- very it is desired by its exquisite flavor and aroma. In this study was evaluated the composition of the volatile compounds in pulp cocona during the ripening low petals, 5 yellow stamens, and a fruit. Three stages of maturation were studied: green, mature and ripe. The dark-green 5-pointed calyx. The volatiles were isolated by continuous liquid-liquid extraction with pentane- thin, tough skin is coated with a dichloromethane 1 : 1 (v/v) and researched by GC-FID and GC-MS. A total of slightly prickly, peach-like fuzz un- 76 compounds were found in this fruits, 40 in green fruits, while up to 67 were til the fruit turns fully ripe, then it present in mature and 66 in ripe fruits, most of them reported for the first time. is smooth, golden- to orange-yellow, During the maturation an increase in concentration of esters and alcohols, and burnt-orange, red, red-brown or decrease in carbonyl compounds were observed. Similar compounds were found deep purple-red, and has a bitter in the three maturation stages, but higher concentration of methyl salicylate taste. Inside the fruit is found a 6 to together with a-terpineol and smaller proportion (Z)-3-hexenol were found, while 10 mm layer of cream-colored, firm aldehydes as (Z)-3-hexenal, (Z)-2-hexenal, (E)-2-hexenal and hexanal decreased flesh enclosing the yellow, jelly-like with maturation. central pulp. The cut-open fruit has

✤ Correspondence: Clara Elizabeth Quijano. Universidad de los Andes, Facultad de Ciencias, Dpto. de Química, Cra. 1a Este No. 18-A-10 Edif. (Q-826), Bogotá, Colombia. E-mail: [email protected] 133 Revista CENIC Ciencias Químicas, Vol. 37, No. 3, 2006.

a faint, tomato-like aroma. The pulp An internal standard (0.45 mg of n- stance with considering calibration has a mild flavor faintly suggestive decanol) was added to the superna- factors, that is F = 1 for all com- of tomato, while the pulp has a pleas- tant, which was immediately sub- pounds.. Results were compared by ant, lime-like acidity.2 The fruits is jected to a continuous liquid-liquid ANOVA and Duncan’ test. prized for making jam, marmalade, extraction used as mixture solvents paste, and jelly, and is sometimes with 250 mL of pentane-dichloro- RESULTS AND DISCUSSION pickled or candied. It is also often methane 1 : 1 (v/v) 7 for 8 h . The ex- The maturity of cocona fruit is processed as nectar or juice which, tracts were dried over anhydrous related to changes in the carbohy- sweetened with sugar, is a popular sodium sulfate and concentrated to drates, nonvolatile organic acids, cold beverage. 0.2 mL with a Kuderna-Danish ap- volatile compounds, pigment and The chemical composition of the paratus with a Vigreux column (40 ºC) pectin content. Table 1 shows the aroma of L.4 and to 0.2 mL . All the isolations were quality measurements of fruits from Solanum vestissimum Dunal,5 have made by duplicated. green, mature and ripe stages. With been reported. Despite the pleasant respect to the content of soluble sol- aroma of cocona fruit, to date its vola- Gas chromatography (GC-FID) ids, the green fruits show a lower tile compounds have only been stud- An HP 6890 GC with FID equip- value than the mature and ripe ied for Brazilian fruits,6 identifying ped with a fused silica HP-Innowax fruits. The pH values were slightly 20 volatile constituents. Although capillary column (60 m X 0.25 mm superior in mature and ripe fruits this fruit is not yet commercially i.d. X 0.25 mm film thickness) was than green fruits due to a decrease cultivated in Colombia its distinc- used. The temperature program was of organic acids. The hardness of tive exotic flavor makes it promis- 4 min isothermal at 50 oC and then fruits decreased obviously with ing as a raw material for the food 40 - 220 oC at 4 °C/min . The carrier maturation, probably due to the industry. flow rate (nitrogen) was 1 mL/min . solubilization of pectin. The objective of this study was to Injector and detector temperatures The volatile compounds from establish a relationship between the were kept at 220 oC . Volumes of 1 mL three different stages of maturity of compositions of the volatile during were injected with a split ratio (1:10). cocona fruits were isolated by liquid- three maturation stages of cocona Retention indices were calculated liquid extraction. The final extracts

(Solanum sessiliflorum Dunal) fruits for compounds relative to a C8 - C25 had different odor characteristics; grown in Colombia. n-alkanes mixture. those extracts from green fruits had typical herbal notes, while mature MATERIALS AND METHODS Gas chromatography-mass spec- fruit extract had a predominantly Fruits trometry (GC-MS) sweet odor and the extract from ripe Fresh green, mature and ripe An HP 6890 Series II coupled to fruits possessed a sweet fruity odor fruits were picked from the same a HP-5973N mass detector and with with lower herbal notes. bushes grown in Caquetá, Colombia. a similar column and temperature Table 2 presents the identified The fruits were collected, provided program as for the GC-FID tech- compounds and their quantitative and identified by Colombian Insti- nique was used. Mass spectra were distribution. They were identified tute of Agricultural (ICA). This fruits obtained by electron impact ioniza- by comparing mass spectra and GC were transported by airplane, imme- tion at 70 eV . retention indexes. In total, 76 vola- diately after arrival they were tile compounds were identified, cor- checked and tested, so that the iso- Qualitative and quantitative analy- responding to 29 esters, 13 terpenes, lation of volatile compounds was sis of volatile compounds 12 carbonyls, 10 alcohols, 5 acids, concluded within 24 h after harvest. Constituents were identified by 3 lactones, 2 phenols and 2 hydro- Fruit puree was prepared in a com- comparison of their mass spectra carbons. In the extract from green mercial blender for analysis. with those in NBS, NIST or our fruits 39 compounds were identified, FLAVORLIB data base and con- while in the other two maturation Quality analysis firmed in many compounds by their stages up to 70 volatiles were found. Soluble solids were determined relative retention indexes. Mass Among the identified compounds, by refractometer at 20 oC and were spectra from the literature,8-10 were 73 were reported for the first time in expressed as °Brix. Measurement of also compared. this fruit. pH was accomplished with a poten- Quantitative determinations Comparing qualitative results tiometer and physical hardness was were calculated approximate con- with the reported composition of determined with an Effesi mod. FT centrations of volatile compounds other Solanum species,3,4 some con- 327 testing manual machine with a from GC-FID peak areas according stituents seems to be common in 1 cm diameter cylindrical probe. to the internal standard method us- this plant family, like (Z)-3-hexenol, Samples were punctured to 2 cm ing n-decanol as reference sub- linalool and α-terpineol. The identi- depth. Three fruits from each ripen- ing stage were evaluated for hard- ness in the equatorial part of the Table 1. Quality measurement of cocona fruit at three maturation stage. fruit. Qnuality item GereeMeaturRip Isolation of volatile compounds Enxternalcolorgereereeddishorangredpurpl

One kilogram fruits of each matu- o ration stage (peeled and without Solublesolids(Barix)3a.74b.08.2 seeds) was mixed with 1.5 L of dis- paH 3b.84c.04.1 tilled water, blended in a commercial Hardness(kgf/cm2)a9b.07c.25.4 blender for 10 min and then centri- fuged at 10 000 r/min, 5 ºC for 20 min . Different letters on the same row indicate significant differences at p < 0.05. 134 Revista CENIC Ciencias Químicas, Vol. 37, No. 3, 2006.

Table 2. Quantitative comparison (mg/kg) of volatile components from different fied lactones γ-octalactone, γ- maturation stages of cocona fruits. decalactone and δ-undecalactone, and the identified phenols 4- CIompound RnGereeMeaturRipvinylguaiacol and eugenol are re- ethylacetate+ 8a255b47c8125ported for the first time in Solanum species. 3-methylbutanal+ 9a023a52a523 The quantitative analysis showed + −− 2-pentanone 9a7526bba total amount of 3.53, 5.27 and methyl3-methylbutanoate+ 1a0204b56c0856.61 mg/kg of pulp from green, ma- ture and ripe fruit, respectively. Car- hexanal+ 1a0253b561c5652 bonyl compounds (2.36 mg/kg) pre- + ethylbutanoate 1a0301a52b036sented the highest concentration in 1-propanol+ 1a0354b53c625green fruit, whereas esters showed ethyl2-methylbutanoate+ 100452ba3c547the highest content in mature and

+ ripe fruits (2.18 and 2.68 mg/kg, re- 3Z-hexenal 1a0704b844c26402spectively). It is interesting to note + − butylacetate 1073a1c25b165that the amount of C6-aldehydes, in- 2Z-pentenol+ 1a1125a86a372cluding (Z)-3-hexenal, (Z)-2-hexenal, (E)-2-hexenal and hexanal could be 1-butanol+ 1a1358b53c213 related to the maturity of the fruit + − heptanal 1165a3b2b21by a significant decrease of their 2Z-hexenal+ 1a1859b055c86352concentrations. The amount of ter- 1-dodecane+ 1a19924−b−bpenes, alcohols, acids, phenols and lactones increased with maturation + 2E-hexenal 1a2182b871c5379of the fruit. 4Z-heptenal+ 1a225168−b−bThe major volatile constituents cyclopentanone+ 1a23642−b−bin green fruit were (Z)-2-hexenal β+ (0.90 mg/kg), (Z)-3-hexenal (0.48 mg (E)--ocimene 1241−a2c5b138 /kg), hexanal (0.36 mg/kg) and (E)-2- + − cyclopentanol 1280a1c2b57hexenal (0.29 mg/kg). Due to their hexylacetate+ 1303−a2c6b57green notes, it can be supposed that the hexenals have the major impact 2Z-hexenylacetate+ 1a3204a55b685 on the flavor of green fruits. On the + − 3Z-hexenylacetate 1335c3c5b45other hand, the most abundant vola- 16-hexanol 1a355b81c10135tile were methyl salicylate (0.76 mg isopropylhexanoate+ 1385−a8bb12/kg), (Z)-2-hexenal (0.59 mg/kg) and

+ (Z)-3-hexenal (0.43 mg/kg); whereas 3Z-hexenol 1a3918b51c58259methyl salicylate (0.85 mg/kg), α-ter- butylhexanoate+ 1a3994b55b853pineol (0,42 mg/kg), (Z)-3-hexenal cis-linalooloxide(5-membered)+ 1418−a2c5b42(0.40 mg/kg) and (Z)-2-hexenal (0.35 mg/kg) show the highest con- aceticacid+ 1a4253b15c263 centration in the ripe fruits. + − ethyloctanoate 1430a5c3b35Methyl salicylate has pungent- hexyl3-methylbutanoate+ 1432−a2c5b58sweet and fruity-rooty odor; also the pentylbutanoate+ 1440−a−a25term minty is often used as descrip- tion of the odor of this ester, while + 2-furfural 1a4451b02c538the odor of a-terpineol is delicately octylacetate+ 1454−a4b6b56floral and sweet of Lilac type.11 camphor+ 1485−a2b1b35Due to their characteristics, and their large amounts in mature and benzaldehyde+ 1a4901b32c535 ripe fruits, the esters might have + − 2-octylacetate 1493a3b0b35an impact on the aroma of cocona linalool+ 1a5033b61c25185fruits. In general, the significant in- ethyl3-hydroxybutanoate+ 1521−a5c6b85 crease in concentrations of (Z)-3- + − hexylbutanoate 1a5302a535bhexenol, a-terpineol and the esters butylhexanoate+ 1535−a8859was in agreement with the results 1-octanol+ 1550−a2b7b34reported during maturation of S. 12 + vesstisimun fruits. (Suárez & trans-linalooloxide(5-membered)1a5551b52c848Duque, 1992). ethylnonanoate+ 1568−a−a26b ACKNOWLEDGMENTS methylbenzoate+ 1590−a2c5b12 Grateful acknowledgements are hexylhexanoate+ 1a5931b251c58170 expressed to the Faculty of Sciences + −− 2E,4E-octadienal 1a59934bbof the University of the Andes for the citronellylacetate+ 1603−a1c3b25financial support. We thank Jaime Campos for supplying the fruits To be continued on following page. used in this study. 135 Revista CENIC Ciencias Químicas, Vol. 37, No. 3, 2006.

Table. 1. (Continued) 4. Brunke E.-J., Mair P. & Ham- merschmidt F.-J. Volatiles from CIompound RnGereeMeaturRipnaranjilla fruit (Solanum quitoense L.). GC/MS analysis and sensory + benzoicacid 1a6181a51a213evaluation using sniffing GC. Jour- ethylbenzoate+ 1642−a3b0b25nal of Agricultural and Food Chem- istry 37, 146-148, 1989. α+ − -farnesene 1658a5c0b72 5. Suárez, M. & Duque, C. Volatile con- ethyl3-hydroxyhexanoate+ 1673−a65b−astituents of lulo (Solanum vestis- simum D.) fruit. Journal of Agricul- α-terpineol+ 1a6812b51c56425 tural and Food Chemistry, 39, 1496- benzylacetate+ 1689−a1c01b1781500, 1991. 6. Marx F., Andrade E.H.A. & Maia J. 1-heptadecane+ 1701−a14b−a A.G. Chemical composition of the + − geranylacetate 1712a1c35b258fruit of Solanum sessiliflorum. + Zeitschrift für Lebensmittel-Unter- 4-vinylguaiacol 1728−a2c5b45 suchung und -Forschung A 206, 364- + − − phenylethanediol 1735a35ba366, 1998. β-selinene+ 1725−a−a145b 7. Drawert F. & Rapp A. Gas-Chroma- tographische Untersuchung pflanzli- m1ethylsalicylate 1a751b377c58850cher Aromen. I. Anreicherung, geranylacetone+ 1794−a−a25bTrennung, Identifizierung von

+ flüchtigen Aromastoffen in Trau- hexyloctanoate 1a8001b07c8125benmost und Wein. Chromatogra- ethyldodecanoate+ 1835−a5c2b75phia, 1, 446-457, 1968.

+ 8. Jennings W. & Shibamoto T. Quali- hexanoicacid 1a8495b44c312tative Analysis of Flavour and Fra- benzylalcohol+ 1a9651a21a821grance Volatiles by Glass Capillary γ+ Gas Chromatography. New York: -octalactone 1886−a2c8b35 Academic Press, 135, 1980. β+ − -ionone 1913a1c8b27 9. MacLafferty F.W. & Staffer D.B. + TheWiley/NBS Registry of Mass octanoicacid 2035−a3b5b25 Spectral Data. New York: John Wiley hexylbenzoate+ 2a0562b14c254& Sons, 1989. γ+ -decalactone 2100−a3c5b5610. Adams R.P. Identification of Essen- −tial Oil Components by Gas Chroma- e0ugenol 212a8c5b156tography/Quadrupole Mass Spec- farnesylacetate+ 2a2222b34c585troscopy. Carol Stream, IL: Allured Publishing Co., 2001. + − ethylhexadecanoate 2248a6c5b14211. Arctander S. Perfume and Flavor δ-undecalactone+ 2a2181b55c685Chemicals. Montclair, NJ: Published + − −by the author. 1969. decanoicacid 2358a47ba12. Suárez M. & Duque C. Change in E-8phytol* 2a562b53c5153volatile compounds during lulo (Solanum vestissimum D.) fruit RI Retention indices on Innowax capillary column. maturation. Journal of Agricultural Different letters on the same row indicate significant differences at p < 0.05. and Food Chemistry, 40, 647-649, + Identified for the first time. − Not detected. 1992.

BIBLIOGRAPHY 2. Clement C.R. & DaSilva D.F. Amazo- 1. Moraes V.H.D., Muller C.H., DeSoucza, nian small fruits with commercial po- A.G.C. & Antonio, I. C. Native fruit tential. Fruit Varieties Journal, 48, species of economical-potential from 152-158, 1994. the Brazilian Amazon. Angewandte 3. Morton J. Cocona. En: Fruits of warm Botanik, 68, 47-52, 1994. climates. Miami, FL., 428-430, 1987.

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