AROMA CONSTITUENTS OF PLUM BRANDY

Transcription

1 AROMA CONSTITUENTS OF PLUM BRANDY E. A. CROWELL and d. F. GUYMON Presented at the Annual Meeting f the American Sciety f Enlgists, June 23, 1972, Mnterey, Califrnia. Respectively Staff Research Assciate and Prfessr f Enlgy, Department f Viticulture and Enlgy, University f Califrnia, Davis, Califrnia Financial supprt by the Califrnia Prune Advisry Bard is gratefully acknwledged. Frm a M.S. thesis in Fd Science by the senir authr. Accepted fr publicatin Nvember 2, ABSTRACT The arma cmpnents f an experimental brandy prduced frm Califrnia French prunes were cncentr~tted by slvent extractin and islated by gas chrmatgraphy. Individual cmpunds were identified by infrared spectrscpy and retchtin data n SE-30 and FFAP liquid-substrate clumns. Substances identified included aliphatic fatty acid esters, free fatty acids, armatic aldehydes, esters, and alchls, ethyl lactate, furfural, eugen(~l, and unsaturated aliphatic aldehydes. The cnstituents f the experimental brandy were cmpared with thse f fur samples f imprted plum brandy. Quantitatively, the imprted samples cntained higher levels f benzyl alchl, 2-phenethyl alchl, ethyl benzate, and eugenl, but much less f the ethyl esters f fatty acids. Ethyl lactate was 2-4 times higher in French Quetseh and Mirabelle and tw brands f Yugslavian slivvitz than in the experimental brandy. Brandies derived frm fruits ther than grape are referred t as fruit brandies. The nly fruit brandy prduced cmmercially in any quantity in the United States is a small amunt f applejack, a distillate f fermented apples. Brandy prducts which many cnsumers assciate with varius fruits are prepared frm grapes r grape residue r, mre recently, frm citrus cncentrate, r by adding a natural fruit flavr t neutral brandy. The alchl cntent is nt derived frm the fruit that flavrs the prduct. In cntrast, several Eurpean cuntries prduce true fruit brandies in large amunts, ften highly regarded fr distinctive flavrs that reflect the fresh fruit frm which they are prduced. The generic name fr plum brandy is slivvitz. It is the natinal drink f the Middle Eurpean cuntries f Rumania, Hungary, and, particularly, Yugslavia. Imprted Yugslavian slivvitz is ften aged in ak, mulberry, r acacia cperage (9). Mst samples are light yellw and have little evidence f wd-aged character. Plum brandies prdueed in the Alsace regin f France are named fr the variety f fruit used, i.e., Quetseh and Mirabelle. Yugslavia, the leading plum-prducing cuntry in Eurpe, prduced abut 20 millin 159 gallns f slivvitz in 1969 (1). The variety used is apparently quite similar in prperties t the prune-plums grwn in Califrnia fr the prductin f dried fruit. Hansen (5) defined a prune as "a plum that can be satisfactrily dried whle withut fermentatin at the pit." The main prperties necessary fr gd drying are a high sugar cntent and relative firmness. Only a few varieties f Eurpean plum (Prunus dmestica) fulfill these requirements. The French prune ('Prune d'agen') is by far the variety f chice fr dried fruit, bth pitted and unpitted. Althugh several grwing districts f Califrnia have the sil and climate needed fr grwing prunes, urbanizatin and prductin csts have slwly shifted prune acreage frm the castal valleys t high-yield Sacrament and San Jaquin districts. This shift, cmbined with weather cnditins, imprved grwing methds, and less bvius factrs, has led t years f verprductin. Always present in additin is a significant yield f cullage fruit, usually representing defects f size r side-split. Grwers are therefre interested in turning bth surplus and cull fruit int prfitable prducts acceptable t the American cnsumer.

2 One such prduct under cnsideratin is a distilled alchlic beverage f the slivvitz type. This study was dne t cmpare an experimentally prduced brandy frm fermented Califrnia French prunes with fur examples f imprted Eurpean prducts: a Quetsch, a Mirabelle, and tw samples f Yugslavian slivvitz. The imprted brandies are all termed "plum brandy," and the experimental sample "prune brandy," in keeping with the definitin f Hansen (5), thugh there is little distinctin therwise. MATERIALS AND METHODS Nature and surces f plum brandies studied: The primary material used was an experimentally prduced prune brandy and tw separate fractins f it. The fur imprted cmmercial plum brandies were btained frm retail utlets. Tw were different brands (A and B) f Yugslavian slivvitz. Bth labels said they were prduced frm "fresh, selected, ripe plums," and bth were light yellw. The thers, prduced frm tw types f French plums, were essentially clrless. The labels indicated they were nt aged. The designatins used herein crrespnd t the fllwing" PLUM BRANDY--160 Fractins 1-5 were cmbined t give a brandy f prf. Fractins 6-8 were cnsidered the tails prduct. The brandy was reduced t 100 prf with distilled water, cled t 0 C fr several days and filtered. Chill-prfing was required since an intense white haze frmed frm reductin with water. The chill-prfed brandy and samples frm certain f the fractins were used in this study. Brandy extractin and cncentratin: A chsen vlume f brandy r f a brandy fractin ( ml) was diluted with water t reduce the ethyl alchl cntent t abut vlume %, and extracted in a separatry funnel with three successive 100-ml prtins f reagent-grade methylene chlride. When acidic cmpnents were t be remved, the cmbined slvent layers were then extracted three times with 50-ml prtins f cld 5% NaOH. After acids were remved, the cmbined slvent layers were washed three times with 50 ml distilled water, dried with anhydrus magnesium sulfate, and filtered. The majr part f the CH2C12 was distilled ff, and the extracts were finally cncentrated t ne ml in a stream f nitrgen. Designatin Origin Label Infrmatin Slivvitz A Yugslavia 94 prf, 8 years ld Gas chrmatgraphy (GC) and infrared spectr- Slivvitz B Yugslavia 100 prf, 8 years ld scpic equipment and perating cnditins: An Quetsch France (Alsace) Quetsch plum brandy, 96 prf F & M gas chrmatgraph, mdel , equipped Mirabelle France (Alsace) Mirabelle plum brandy, 96 prf fr bth hydrgen-flame inizatin and thermal- The experimental brandy was prduced in ur cnductivity (TC) detectin was used. The latter pilt plant facilities, frm tree-ripe French (Agen) nndestructive mde f detectin was used mst prunes grwn in Clusa cunty. Abut ne and ne- frequently since the main bjective was t cllect half tns f fruit were crushed in a rller-type and identify sme f the primary cmpnents f crusher, and the whle mash was fermented at rm the fruit brandy samples. Used fr separating the temperature (70 t 80 F.) using regular wine cmpnents were tw GC clumns: plar FFAP yeast. N sulfur dixide was added. The sluble (5% w/w), plus Shell Inx antixidant (0.1% slids f a sample f juice expressed frm the w/w) cated n a 60/80-mesh Chrmasrb G AWinitial mash was 24.7 Brix. Other analysis f the DMCS; and nnplar SE-30 (5% w/w) plus juice gave a ttal acidity f 0.56 g/100 ml as malic Igepal C0-880 (0.05% w/w), added t reduce peak acid, ph 4.20, 12.4 g/100 ml f reducing sugars tailing f plar cmpunds, cated n 60/80-mesh and 4.4 g/100 ml f sucrse. After 5]/~ days n Chrmasrb G AW. Bth clumns were thin-walled further decrease in sluble slids was bserved s stainless-steel cils, 4-ft x 1/~-in. OD, and bth were fermentatin was cnsidered cmplete. The fermented mash tested 8.5 Brix and 9.9% alchl by vlume, indicating a large amunt f unfermentable sluble slids. The fermented whle mash, amunting t abut 280 gallns was distilled in a 350-gal. cpper pt still and 87.1 wine gallns f lw-wines distillate at 45.6 prf was btained. The lw wines were redistilled in the same pt still and the fllwing successive fractins were cllected. Fractins Vlume, gallns Prf Heads inserted fully int the injectin prts t prvide n-clumn injectin. Helium carrier-gas flw rate with the TC detectin was 50 ml/min, and injectr prts and detectr temperatures were respectively, at 210 C and 250 C. Since the cncentrated brandy samples used cntain cmpnents having a wide range f prperties and vlatilities, the chrmatgraph was used with an F & M prgrammer, mdel 240, t prvide linear-prgrammed temperature chrmatgraphy. Fr arma cmpnent separatins, the FFAP clumn was prgrammed frm 100 t 200 C at 7.5 C/min and held at 200 C until all peaks had emerged. The SE-30 clumn was prgrammed frm 70 t 200 C at the same rate and held at the higher temperature until all cmpnents had passed thrugh the clumn.

3 161--PLUM BRANDY A Beckman IR-8 spectrphtmeter equipped with a 5X beam cndenser was used fr all infrared studies f separated cmpunds. The cmpunds emerging frm the gas chrmatgraph were trapped in thin-walled 300-mm-lng capillary tubes kept cld with packets f dry ice. After peak cllectin the tubes were sealed with an xygen trch and stred in the dark until the cntents culd be examined. Except when cmpnents were present in large amunts, accumulating enugh f a single cmpnent fr infrared (IR) analysis required repeated injectins f a brandy cncentrate with subsequent peak cllectin. The cntents f the capillary tubes were eluted with methylene chlride and analyzed as thin films between NaC1 plates after slvent evapratin. RESULTS AND DISCUSSION Initial gas chrmatgrams were btained fr cncentrated extracts f the several experimental brandy fractins, using the FFAP clumn. Threemierliter samples f 200:1 cncentrates f the heads fractin and each brandy fractin frm 1 t 5 were injected, using the hydrgen flame inizatin detectr. Helium carrier-gas flw, hydrgen, and air flws were respectively 50, 40, and 400 ml/min. The chrmatgrams shwed very large peaks fr numerus cmpunds in the heads fractin, and all f thse were als present in brandy fractins 1-5, thugh in decreasingly lwer amunts. On the ther hand, the chrmatgrams fr fractin 5 exhibited peaks fr ther cmpunds much greater than in the preceding brandy fractins. This was the basis fr using the heads fractin as the surce material fr btaining cmpunds relatively abundant in heads and crrespndingly fr using fractin 5 fr ther cmpunds mre abundant in this fractin. Guymn (3) discussed the factrs that cause cngeners f grape wine with biling pints well abve the perating temperature in stills t distill ver int brandy. The brandy heads fractin prvides a material enriched in high-biling cmpunds f very lw slubility in water r weak alchl slutins, whereas the last brandy fractin is a mst cncentrated surce f water-sluble high-biling cmpunds. a variety f distilled alchlic beverages and appear t be bth natural cmpnents f fresh fruits and, mre imprtantly, prducts f fermentatin (4). Cmpnents islated frm brandy fractin 5" Five successive 25-micrliter samples f a 200:1 cncentrate f brandy fractin 5 were injected nt the FFAP clumn t cllect enugh f each cmpnent fr examinatin. Figure 1 is a chrmatgram f these injectins. The materials labeled 4 and 5 were cllected as znes cntaining several peaks and were reinjeeted n the same clumn fr cllectin f each individual peak. Peak 1 (retentin time, RT, 2.5 min) was identified as ethyl lactate by IR analysis and retentin data. Althugh an ethyl ester, the hydrxyl grup in the acid functin apparently increases the plarity and water slubility f ethyl lactate enugh t cause it t accumulate in this later brandy fractin. This ester, cnsidered an imprtant cngener f genuine slivvitz (7), has a pleasant fruity dr. Furfural (peak 2, RT 4.1 min), virtually absent frm cntinuus-still prducts, is prduced during pt distillatins frm the prlnged heating f residual sugars in the fruit mash and has an unpleasant burnt dr in cncentrated amunts. The material cntained in peak 3 (RT 5.2 min) had a bitter-almnd dr suggestive f benzaldehyde. Their spectrum shwed bands fr earbnylstretching vibratin at 1698 cm -~ (a shift t lwer wave number frm the nrmal aldehydie band at ~ as a result f cnjugatin with the unsaturated ring), absrptin bands characteristic f the armatic ring, and exact agreement with authentic 8 BRANDY FRACTION 5 ~ 2. FFAP g I Cmpnents islated frm brandy heads fractin: With the thermal cnductivity detectr installed, several 25-mierliter samples f a 100:1 cncentrate f heads were injected nt the FFAP clumn, and three very large peaks eluting at 4.1, 6.9, and 9.6 minutes were cllected after each injectin. Withut further purificatin, IR analysis f these three cmpnents plus retentin data and IR spectra f authentic cmpunds served t identify these cmpunds as the ethyl esters f eaprylie, eaprie, and laurie acids. These ethyl esters and thers have been islated in relatively high cncentratins in i Z~, 2, II I ~, I ~'~ RETENTION TIME, MINUTES Figure 1. Gas chrmatgram fr experimental plum brandy fractin #5; FFAP clumn prgrammed 100 t 200 C at 7.5 C/min, held at 200 C t end, attenuatin X16, TC detectr, 25 micrliters f 200:1 cncentrate.

4 benzaldehyde in the fingerprint regin. Benzaldehyde is an imprtant cngener f stne-fruit brandies and is prbably a hydrlysis prduct f amygdalin, cntained in the fruit pits. The aldehyde has been islated in a variety f fruit brandies (7,8), in peach fruit (2,6), and in cherry essence (13). The materials cntained in zne 4 were reinjected n FFAP and were shwn by IR data t cntain n-butyric acid (RT 6.2 min) and isvaleric acid (RT 6.75 rain). Bth cmpunds are cmmn fermentatin prducts f a maldrus nature. The peaks in zne 5 were rechrmatgrammed (FFAP) and cllected fr IR analysis. The small cmpnent at RT 8.6 min culd nt be cllected in sufficient quantity fr evaluatin, but had the very distinctive dr f il f wintergreen (methyl salicylate). Retentin data and IR spectrum fr the peak emerging at 9.3 min served t identify n-hexanic acid. The peak at 9.7 min exhibited an IR spectrum in perfect agreement with that f benzyl alchl as given by.jennings and Sevenants (6) and with the spectrum frm a sample f the authentic cmpund. Retentin data n bth GC clumns verified the identificatin. The last peak f zne 5 (RT 10.2 min) was shwn t be 2-phenethyl alchl, a cmmn and imprtant fermentatin prduct having a strng rse-il dr. Peaks 6, 8, and 9 were, respectively, fund t be free caprylic, capric, and lauric acids. An interesting material, peak 7, had a very cmplicated IR spectrum but escaped identificatin at that pint. It is discussed in the results f a later cllectin run. Althugh peak 10 had the crrect retentin time and an IR spectrum similar t benzic acid, its identificatin is uncertain. Peak 11 remains unidentified. Cmpnents islated frm brandy heads after remval f free acids: Fur hundred m! f heads were extracted with methylene chlride, the slvent layers were extracted with cld 5% NaOH, and the slvent stripped t give a final vlume f 1 ml (400:1 cncentrate with free acids remved). Eight 30-micrliter injectins were made n the SE-30 clumn, and eluted substances were cllected after each injectin, as single peaks when pssible r as znes f several peaks fr rechrmatgraphy. A chrmatgram is shwn in figure 2. The very large peaks befre zne 1 are largely slvent, ethanl, and fusel il cmpnents. In cnsidering the substances cllected as single peaks, peaks 4, 6, and 8 were, respectively, identified previusly as ethyl caprylate, caprate, and laurate. Peaks 10, 12, and 14 were identified frm IR and retentin data as additinal esters f this hmlgus series, respectively, ethyl myristate, ethyl palmitate, and ethyl stearate. Upn rechrmatgraphy (SE-30) f zne 1, fur peaks were detected and trapped. The first peak was cntaminatin frm the large amunt f isamyl alchl eluting just befre zne 1. A secnd PLUM BRANDY--162 peak (RT 2.25 min) was identified as furfural, als islated befre. A sample f the very large cmpnent (RT abut 2.8 min) was trapped using nly the very tp prtin f the peak. The peak material was identified as isamyl acetate, again n the basis f IR and retentin. The tw peaks f zne 2 were cllected and subjected t IR analysis. The first, at RT 3.8 min, was lst thrugh evapratin frm the salt plates in spite f all effrts t retain it. The secnd peak, at 4.5 min, was identified as ethyl caprate, anther ester f the hmlgus series f fatty acidethyl esters. The material frm zne 3 (RT rain) was reinjected n the SE-30 clumn, and six individual substances were trapped. Of the six, nly tw yielded sufficient amunts fr IR analysis. The material frm the larger peak, at 6.3 min, had a pleasant lemnlike dr. The IR spectrum is discussed later in a sectin f nnester nn-acid cmpnents f.the brandy heads. The IR spectrum fr the smaller peak at 7.4 rain and retentin data shwed this substance t be ethyl benzate. Ethyl benzate has been islated frm a variety f prducts, including fresh peaches (2,12), cherry essence (13), and rum (10). Rechrmatgraphy f zne 5 shwed fur peaks trapped individually. The infrared spectrum fr the largest peak (RT abut 9.7 min in figure 2) had precisely the same features as the ethyl esters f even-numbered fatty acids islated befre. Its retentin was exactly midway between ethyl caprylate and ethyl caprate. This cmpund culd be the ethyl ester f the dd-numbered C9 pelargnic acid. Althugh ethyl pelargnate has been reprted in a variety f alchlic beverages (10,14), its presence here is nt certain. t BRANDY HEADS FRACTION : SE30 ~ z == ~ ' II I I RETENTION TIME, MINUTES Figure 2. Plum brandy heads fractin (fatty acids remved); SE-30 clumn prgrammed 70 t 200 at 7.5 C/min, held at 200 C t end, attenuatin X16, TC detectr, 30 micrliters f 400:1 cncentrate. l-2-t

5 PLUM BRANDY Identificatin f the cmpunds cntained in znes 5, 7, 9, and 11 was cmplicated by the lw amunts present in each individual peak. Hwever, the IR spectra fr the first peaks f zne 5 (RT 8.6 min), zne 7 (RT 12.3 min), and zne 9 (RT 15.2 min) appear t be straight-chain aliphatic esters n the basis f carbnyl-stretching absrptin at 1735 cm -~ and ther features. In additin, the spectra fr the very small peaks f znes 5 (RT 10.1 min) and 7 (RT 13.3 min) respectively agree perfectly with thse fr methyl caprate and methyl laurate (15). Cmpnents frm alkaline-hyrlyzed heads: Fur hundred ml f brandy heads were mixed with 200 ml 0.1N NaOH and refluxed fr 16 hurs. After cling, 210 ml 0.1N HC1 and 400 ml distilled water were added, and the slutin was extracted with three prtins f methylene chlride. The slvent layers were extracted three times with 50 ml cld 5 % NaOH, then washed three times with water. The s~vent was then dried and cncentrated t ne ml. This prcedure remves bth acids and esters frm the test sample,' but cautin must be used in deciding whether islated cmpunds are nrmal brandy cmpnents r are artifacts prduced by heating in alkaline slutin. A sample amunting t 35 micrliters f this 400:1 cncentrate revealed 18 peaks eluted in the first 12 minutes when injected n the SE-30 clumn. Of these, all but six were recgnized frm previus studies r were present in t lw amunt fr cllectin, n-hexyl alchl (SE-30 RT 3.2 min), althugh present in mst ther fractins studied, was islated and identified in this cncentrate. The IR spectrum and retentin data fr a trace cmpnent eluting at 9.3 minutes matched perfectly with thse f cinnamaldehyde. Since cinnamn dr was frequently nted frm injectins f nnhydrlyzed brandy samples, cinnamaldehyde is cnsidered a natural cngener rather than an artifact. Tw cmpnents with retentins f 6.4 and 11.4 min were described as lemnlike in dr, the first the mre intense. Frm IR spectra, bth cmpunds appear t be unsaturated aliphatic aldehydes, differing in the psitin f unsaturatin. Abslute identificatin was nt pssible frm the data. In additin, a peak eluting at 6.7 min was tentatively identified as a substituted armatic aldehyde. GC cmparisn f experimental and imprted is plum brandies: Twenty-five micrliters f 250" cncentrates f the experimental brandy, the cmpletely reslved. Althugh this substrate was used successfully t separate cmpnents f experimental brandy fractin 5, analysis f the cmpsite prduct (all five fractins cmbined and reduced t 100 prf) was better with the SE-30 clumn. SE-30 is nt satisfactry fr free fatty acids, hwever, since these are either destryed r d nt elute frm the clumn. Chrmatgrams are shwn fr the experimental brandy in figure 3, and (n SE-30) fr the imprted samples in figure 4. Several features f these chrmatgrams illustrate differences between the experimental and imprted brandies. Benzyl alchl, 2-phenethyl alchl, and ethyl benzate (SE-30, respectively, peaks 6, 9, and 10) are significant cmpnents f i EXPERIMENTAL PRUNE BRANDY L 12 9 i0 8 z ~.,....,j,2', 'j....,., " 18 ii I0 Quetsch, the Mirabelle, and the tw slivvitzes.... ~.,,..,..,.. ~,,,, , were injected nt bth the FFAP and SE-30 ~...,,... clumns. GC perating cnditins fr FFAP were the same as indicated fr figure 1, and thse fr Figure 3. FFAP (abve) and SE-30 (belw) chrmatgrams fr SE-30 were the same as fr figure 2. With FFAP, the cmpnents f such a cmplex mixture are in- Amer. J. Enh Viticult., Vh 24, N. 4, 1973 experimental plum brandy. GC perating cnditins same as indicated fr Figure 1 (FFAP) and Figure 2 (SE-30). 4

6 SLIVOWTZ a SE 30 i nf" ~, x 3Z : S S S ~i! I ~ 2} ,7, ~3 12 l, lo 9 8? , SLIVOVITZ B SE 30 RETENTION TIME, MINUTES x k t f PLUM BRANDY--164 all imprted brandies tested but are present in nly small amunts in the experimental sample. The material cntained in peak 15, SE-30, is present in cnsiderable amunt in bth slivvitz samples This cmpund was cllected frm Slivvitz B and identified by IR and retentin data as eugenl, the primary cnstituent f il f clve. Eugenl is als present in bth the Quetsch and Mirabelle but in nly very lw amunt in the experimental brandy. On FFAP, this cmpund has a retentin time identical t thse f peak 11 and peak 7 (Figure 1) in experimental brandy fractin 5. Reexaminatin f the IR spectrum fr this latter peak material shwed gd similarity t that f authentic eugenl. It was cncluded that eugenl is a cmpnent f all brandies studied, thugh minr in the experimental distillate. Ethyl lactate is an imprtant cngener f plum brandy, and, again, a cmparisn can be made between the experimental and imprted samples. On SE-30 chrmatgrams, this ester is eluted at 2.5 minutes (peak 2), just after furfural (peak 1), and at 2.8 minutes, tgether with n-hexyl alchl n FFAP. The TC detectr was set at x16 fr J ~ 24 ~ 22 zl 20 V9 ~ 17 '6 ~ )4 13,Z II,0 9 e K i ~(TENT~0N TI.E. W~UTES TABLE 1 Cmpunds Identified in Prune Brandy and Retentin Times Relative t Ethyl Caprate fr SE-30 Clumn i Peak Cmpund RRT QUETSCH ~ x 32 seso..... L , 20 ~ t '2 II IO I NIRABELLE ~(~(NT~ TI~, ~TES R e R SE ] e 18 l? )4 I~ 12 II I I x~ 1 furfural ethyl lactate hexyl alchl benzaldehyde 0.36 ethyl caprate hexyl acetate benzyl alchl unknwn 8 unsaturated aldehyde a phenethyl alchl ethyl benzate ethyl caprylate cinnamaldehyde b unknwn 14 ethyl pelargnate a eugenl ethyl caprate aliphatic ester a ethyl laurate ethyl myristate ethyl palmitate ethyl stearate 2.08 Figure 4. SE-30 chrmatgrams fr imprted plum brandies. GC perating cnditins same as fr Figure 2. a Identificatin uncertain. b Exact retentin time uncertain.

7 165--PLUM BRANDY all chrmatgrams, but t keep the ethyl lactate peak n scale, the attentuatin had t be changed t x32 (SE-30 nly) fr the imprted samples, and t x64 fr Slivvitz B. Thus, imprted samples appear t cntain tw t fur times as much ethyl lactate as the experimental sample. Kain and Bandin (7) reprted very high levels f ethyl lactate in "genuine" slivvitz as cmpared with what they described as "synthetic." The SE-30 chrmatgram fr the experimental brandy (Figure 3, bttm) shws relatively large peaks fr the ethyl esters f fatty acids, caprylic thrugh stearic (peaks 11, 16, 18, 19, 20, and 21). Up t ethyl palmitate (peak 20), ethyl caprate (peak 16) is present in the highest cncentratin, as with mst distilled beverages. Amng the imprted plum brandies, nly Quetsch and Mirabelle have appreciable ethyl ester cntent. In them, ethyl caprylate (peak 11) appears equal t r greater than ethyl caprate, and the remaining esters f this series are s lw in cncentratin as t be insignificant. TABLE 2 Identity f Peaks Separated by FFAP Clumn, and Retentin Times Relative t Ethyl Caprate Peak Cmpund RRT 1 hexyl alchl a 0.42 ethyl lactate 2 ethyl caprylate furfural benzaldehyde ethyl caprate isvaleric acid b methyl salicylate ethyl laurate a 1.41 hexanic acid benzyl alchl 9 2-phenethyl alchl caprylic acid a 1.79 ethyl myristate 11 eugenl capric acid a 2.18 ethyl palmitate 13 lauric acid, 2.70 ethyl stearate 14 unknwn -- Multiple cmpunds given fr a single peak number are prly reslved by the FFAP clumn. b Exact retentin time uncertain. Amer. J. Enh Viticult., Vh 24, N. 4, 1973 The brandy cmpnent peaks are summarized in table 1 fr SE-30 and in table 2 fr FFAP. The data are expressed as retentin times relative t that f ethyl caprate, because f the difficulty f exactly reprducing individual retentin times during prgrammed temperature runs. The chrmatgrams and table 2 indicate the relatively pr reslutin btained with the FFAP clumn. LITERATURE CITED 1. Ann. Yugslavia and its grwing prune exprts. Pacific Fruit News. 148 (4276): 2, 7 (1970). 2. D, J. Y., D. K. Salunkhe and L. E. Olsn. Islatin, identificatin, and cmparisn f the vlatiles f peach fruit as related t harvest maturity and artificial ripening. J. Fd Sci. 34: (1969). 3. Guymn, J. F. Hw sme arma cmpunds f wine distill int brandy. Reprt t Wine Institute Technical Advisry Cmmittee, qimnterey, Califrnia, March 13, Guymn, J. F. and E. A. Crwell. Gas chrmatgraphic determinatin f ethyl esters f fatty acids in brandy r wine distillates. Amer. J. Enl. Viticult. 20:76-85 (1969). 5. Hansen, C. J. Prune prductin in Califrnia. Cllege f Agr., University f Califrnia, Califrnia Agr. Ext. Serv. Circ. 180 (1951). 6. Jennings, W. G. and M. R. Sevenants. Vlatile cmpnents f peach. J. Fd Sci. 29: (1964). 7. Kain, W. and F. Bandin. Gas chrmatgraphische Untersuchung vn Spiritusen. i1. Uber die fraktinierte Destillatin und die Ausgiebigket vn Zwetschkenbranntweinen. Mitt. Rebe, Wein, Obstbau Fruchtverwertung (Klsterneuburg) 19: (1969). 8. Kevei, J. High temperature gas chrmatgraphic analysis f armatic extracts f fruit brandies. II. Elelmiszervizsgalati Kzlem. 18: (1972). 9. Lichev, V. Aldehyde cmpsitin f Bulgarian plum brandy. Lzarstv i Vinarstv. 7:42-46 (1958). Chem. Absts. 55: 16904f (1961). 10. Liebich, H. M., W. A. Kenig and E. Bayer. Analysis f the flavr f rum by gas-liquid chrmatgraphy and mass spectrmetry. J. Chrm. Sci. 8: (1970). 11. Nyk&nen, L. and H. Sumalainen. The arma cmpunds f alchlic beverages. Teknillisen Kemian Aikakauslehti. 20: (1963). 12. Sevenants, M. R. Studies n the vlatile cmpnents f peach. Dissertatin, University f Califrnia, Davis Library, 51 p. (1965). 13. Stinsn, E. E., C. J. Cley, V. J. Filipic and C. H. Hills. Cmpsitin f Mntmrency cherry essence. 2. Highbiling cmpnents. J. Fd Sci. 34: (1969). 14. Sumalainen, H. and L. Nyk&nen. Investigatins n the arma f alchlic beverages. Naeringsmiddelindustrien. N. 1/2:1-16 (1970). 15. van Wyk, C. J. The arma cnstituents f grapes and wines f VitL~ vinifera var. White Riesling. Dissertatin, University f Califrnia, Davis Library, 121 p. (1966).