in the Aroma of and : A Review

J. MARAIS

Viticultural and OenoJogicaJ Researcll (nstitutc:, Private Bag XS026, 7600 Sfelicnbosch, Republic of South Africa. The author would like to express his thanks and appreciation to Dr. P. 1. Williams of the Australian Research Institute, Glen Osmond, South Australia for critically readinl the: manuscript. Submitted for publication: August 1983 Accepted for publication: October 1983

Thill paper rukw, some .specls of !! and terpene dcrhaUns In ,rapes Ilid wines, such as the IdenUflulion of tbet!: co mpounds, tbeir use In the Idc:ntlfi(ation of and dlfferenthnlnn between cullin... , the err«! of ,rape maturity and wine-makin, t«hnlques on It.rpene concentrations and wine quality, '-" well II transformallons of ItrpenH In .rapes and wlnc:.

Wine quality is determined by a complex balance of A number of prominent aroma components of grapes all the wine aroma components as perceived by sensory and wine, which are of terpenic origin, are also of great evaluation. Although several sensory parameters may importance, Some are listed in Table 2. playa role in the acceptance and enjoyment of wine, the The most prominent terpene compounds occurring flavour of wine is possibly the most important factor. generally and in high concentrations in and F1avour is the result of the interaction between certain aroma related grapes and wines are , , chemical compounds in wine and the senses of smell and nerol, oc -terpineol and hotrieno!' or equal importance of the consumer. Approximately SSO volatile com­ is the great number of terpene compounds which occur ponents have been identified in grapes and wine, and in micro concentrations but which have significant many of these components contribute to the aroma effects on aroma. Different complex combinations of (Schreier, 1979). A large number of components appear terpene compounds are responsible for the characteris­ in micro concenuations in wine, and in many cases these tic aromas of different muscat and aroma related have the most · significant effect on wine quality. With cultivars. These subtle differences in terpene proflles respect to their origin, wine aroma components may be may also occur within the same cultivar originating classified into four groups (Schreier, 1979). from different areas. Typical aroma descriptions of - Originating from the grapes. some important terpenes are floral, rose-like (geraniol, - Produced during the crushing of the grapes by the nerol, rose oxides), coriander (linalool), camphoraceous action of certain enzymes. (linalool oxides), green (nerol oxide) and herbaceous - Produced during fermentation. (Meilgaard, 1975; Simpson, 1979 b). - Produced during maturation of wine . Several studies have been undertaken regarding the A typical cultivar bouquet in wine can be attributed to chemistry of terpenes, their synthesis, systematic classi­ the bouquet of the corresponding cultivar and is fications, etc. (pinder, 1960; Klouwen & Ter Heide, caused by: 1962; Ter Heide, 1968; Ter Heide, 1976). Devon & Scott - Compounds typical of the grape cultivar which are (1972) presented a classification of 4 000 components of uansferred from the grape to the wine without being terpenic nature. Of these components, 400 are mono­ affected by the fermentation process. terpenes and 1 000 sesquiterpenes. and - Compounds equally typical of the grape cultivar sesquiterpenes are characteristic components of the

which are formed from a precursor(s) during rermen­ essential oils produced by plants. Monoterpenes (C lO) tation (Condonnier & Bayonove, 1978). and sesquiterpenes (C l , ) are the lower molecular weight representatives of the terpenoid components and com­ prise two and three isoprene units, respectively. A GENERAL general representation of the biosynthesis of mono­ The wine aroma components responsible for the terpenes and sesquiterpenes, as well as some enzymatic characteristic aroma of muscat and aroma related transformations such as oxidation, reduction and wines, are mainly derived from the grape and are known dehydration. has been summarised by Croteau (197S). as terpene compounds. True muscat cultivars include Terpene concentrations in grapes and wine would Muscat d'Alexandrie, Mario Muscat, and Muscat obviously depend on various factors, such as cultivar, blanc, whereas aroma related cultivars include Weisser region and wine-making techniques. Since the majority , Bukeuraube, Gewilrztraminer, Ferhao Pires of the terpene compounds occur in micro concentra­ and . Terpene compounds may also contri­ lions in grapes and wines, their quantification is quite bute to the aromas of other non-muscat cultivars. Near­ difficult. Consequently, their concentrations are ly SO terpene compounds in grapes and wine are known normally expressed as relative amounts. Examples of at this stage, of which 46 were identified in grapes and absolute terpene concentrations in muscat and aroma 30 in wines (Table I). They include only monoterpenes related grapes and wines, as well as some aroma and sesquiterpenes. threshold values, are shown in Table 3.

S. Afr. J . Eliol. Vltlc: .• vol. 4. No.1. 1913

49 Grvprs Wine Review: Terpenes in the aroma oj grapes and wines 51 TABLE 1 Some terpene derivatives in Irapes and wines. ------o' ,-, 0 ..... _-- Co. 0 -- •.Q<- - SY- - 0 - ~ 0 --- - (p - f' 0' - ~ 0 0 -- ~ - Ce- o 0 .- ~ . -- ~ 0 • .- 60 0 0

References to these terpene derivatives are available in Supplemenu S (1980. wine) and 6 (1981 .lrapc) to the Founh Edition of "Volatile Compounds in Food" (Van Stratm, De Beauveser II: Vi55Cher, 1977). eJ\cept ror: X I Schreier II: Drawert, 1974 b. X2 Schreier, Drawen.t: Junker. 1976 b. X' Rapp.t: Knipser, 1980. X indicates presence in either Ifapcs or wines.

Identification and role of terpene compounds in gnllPCS, are indications that more terpenes other than li nalool wioe aad grape I"v": Considerable research has been and geraniol contribute to muscat and related aromas. done in respect of the identification and contribution of Available li terature since 1974 indicate that the follow­ terpene compounds to the muscat aroma of muscat ing new terpenes had been identified. Schreier, Drawert grapes and wines. Austerweil (1946) was the flJ"st to & Junker (1974) identified 3,7 - dimethylocta - 1,5,7 - suggest that the aroma of muscat grapes can be ascribed trien - 3 - 01 (hotrienol) in grape and wine aromas of (he to terpene compounds, especially linalool and its deriva­ cultivars Weisser Riesling, GewOrztraminer, RuUl.nder , tives. Cordonnier (1956) investigated the .aroma of MOiler Thurgau, Scheurebe. Optima and Rieslaner. muscat wines and tentatively identified Iinaiool, Rapp & Knipser (1979) identified 3,7 - dimethyl- acta- geraniol, ex: -terpineol and Iimonene by means of tbin 1.5 - dien - 3,7 - diol in the grapes and wines of the layer chromatography. cultivars Scheurebe, Weisser Riesljng and Forta, while Webb & Kepner (1957). Stevens el 01. (1966), Webb, Rapp, Knipser & Engel (1980) identified 3,7 - Kepner & Maggiora (1966) and Wenzel & De Vries dimethylocta - 1,7 - dien - 3,6 - diol in the grapes and (1968) undertook further investigations and confirmed wines of the cultivars Blauer Muskateller, SchOnburger, the definite contribution of linalool and geraniol to the Morio Muscat and Sieger. Williams, Strauss & Wilson overall aroma of muscat grapes. Research undertaken in (I 980a) identified 3,7 - dimethyloct- 1 - en - 3,6,7 - triol, this regard till approximately the end of the sixties , 3,7 - dimethyloct - I - en - 3,7 - diol, 3,7 - dimethylocta - mainly concentrated on Muscat d' Alexandrie grapes 1.7 - dien - 3,6 - diol and 3.7 - dimethylocta - 1,5 - dien - and the effects of mainly linalool and geraniol on 3,7 - diol in the grapes and wines of Muscat d'Alexan· muscat aroma. Research workers differed in respect of drie. The same group (1980b) identified 2.6,6 - trime­ the contribution of these terpenes to muscat aroma, and thyl - 2 - vinyltetrahydropyran. cis - and trans - 5 - a clear relationship between the concentrations of these isopropenyl- 2 - methyl - 2 - vinyltetrahydrofuran, 2,2 - compounds and muscat aroma was not always demon­ dimethyl - 5 - ( I - methylpropenyl) tetrahydrofuran , strable. myrceno! and cis - and trans - ocimenol in heated grape Technological development in gas chromatography juice of muscat cultivars. and mass spectrometry accelerated identification of Terrier et 01. (1972 b) and Ri bereau-Gayon et al. terpene compounds and the establishment of the effect of (1975) determined the aroma threshold values of some these compounds on the aroma of muscat and aroma individual terpene compounds as well as terpene mix­ related grapes and wines (Usseglia-.Tomasset, 1966; tures. The authors found linalool and geraniol to be the Usseglio-Tomasset, Astegniano & Matta, 1966; Usseglio­ most important compounds because of the high concen­ Tomasset, 1969; Prillinger & Madner, 1970; Terrier & trations in which they normally occur in muscat grapes Boidron, 1972 a,b; Terrier, Boidron & Ribereau-Gayon, and wi nes, as well as their low threshold values. It was 1972 a,b; Schreier & DraWer!, 1974 a,b; Ribereau­ found that terpenes interact to such an extent that one Gayon, Boidron & Terrier, 1975; Bayonove, Richard & componenl can increase the aroma of another and that a Cordonnier, 1976; Schreier, Drawert & Junker, 1977; mixture could become more aromatic than the most Usseglio-Tomasset & Di Stefano, 1979). aromatic single component which belongs to that mix­ Recently several new terpene compounds have been tu re. For example, the aroma threshold value of linalool identified in grape and wine aromas. In general, there was found to be 100 J.t~/I, while a mixture which

S. Afr. J . E.ol. VIlle .. Vol. 4. No. 2. 19IJ l2 Review: Terpenes in the aroma oj grapes and wines TABLE 3 /\roma threshold values and concentrations· of some lerpeflH in muscat and aroma related IfU.pel (G) and .... ine5 (W). Terpene Aroma Re ference Occur- Concentration ( J,tr/I) Reference threshold renee ( J.l.g//) min. mu. Citronellal W , 7 Geraniol I]. G .. 11»9 1 G 2 2<0 2 G 231 W (+" ) 69 •) W 14 187 7 Hotricnol 11. , G (+) 12. 2 G 7 77 W ) 271 •] W ) 117 7 Linalool 100 G 62 1'" 1 G 11 77 2 G 167 82) W •) W ( +)• '"29 , W 8 7 Nerol ""'00 G 11 447" 1 G ( + ) 41 2 G l' W (+) 16" •) W ] 41 7 CC -Terpineol ""'00 G I' 1" 1 G (+) 14 2 G ] 2l W , J99 •) W 7 7 3,7 - DimethylOtta· 1.5· dim- G 125 1497" 3,7· diol W 24 1114 •7 3,7 - Oimdhyloaa · 1,7 · dim· 3,6· dial G 1. 228 • Neroloxide 100 4 W (+) .. ) W 1 17 7 Rose oxides W (+ , ) ~is . furan linllool oxide > 61XlO G 10 247l' 1 G (+ , 2. 2 W 2 ] W , '"21 7 Irans • Fur.n li nalool o)lide > 61XlO G 21 ... 1 G ( +, 2 W (+ , 1"l' ) W 2 7 tis - Pyran lin alool oxide 3000-5000 G I. m• 1 G ) 7J 2 G 20 .. 6 W (+, 74 ) W 1 7 7 Irans - Pyran linllool oxide 3000-5000 G 20 ". 1 G , .. 2 G 67 271 W 1. •7 2,6,6 • Trimelhyl • 2 - vinyl· Itlrahydropyran W ] "64 , p. Cymcne W , , Limonene W ) "]. , Mvrtene G ( +, 2 ~ TeTpincnc W 6 • , • The concentratioo ran,es represent the sum of different cultiv • .., analyxd. " (+) _ Traces. I. Rii*reau-Gayon, Boidron &; Terrier, 11l7j (Muscat d'Alexandrie, Muscat blanc, Saint Vallier, ItaHa and Muscat Hambaurl). 2. Schrtier, Dra .... er! &: Junker, 11176 a (Rulander, Gewomraminer, Scheurebc and Weiuer Rio:sl.ins). J. Schreier, Dra .... er! &: Junker, 11177 (Maller Thurlau, Weisser" Rieslinl. Morio MUJCat, Gcwllmraminer, RuHtnder and Scheurebe). 4. Simpson, \979. ,. Noble, Flath &; Forrey, 1980 (Weissc:r Rieslinl). 6. Di Stefano, 1981 (A series of .... hile Muscallrapcs from Picmonle). 7. Venini, lnama &: Sartori, 11111 (Weisser Rieslinl)' amongst others included !inalool presenled a threshold & Cordonnier (1971) found linalool, oc-terpineol, value of 91p.gll (Ribereau-Gayon el 01., 1975) . citral, citronellol, nerol and geraniol to occur in 10 to Terpene compounds were also found in minor quanti­ 100 times larger concentrations in muscat than in the ties in some non-muscat cultivars (Stevens, Bomben & non-muscat grape cultivars, Auxerrois, Weisser Riesling McFadden, 1967; Prillinger & Madner, 1970). Bayonove and blanc but in approximately similar relative

S. Afr. J . E.ol. Ville .. Vo l . ... No. 2. 1913 Review: Terpenes in the aroma ojgropes and wines 53 ratios. Theauthorsalso found lhat the addition of these ter­ and aroma related cultivars (Hardy, 1970; Terrier et 01. pene compounds to a neutral grape juice medium in the 1972 b; Cordonnier, 1974; Rapp er oj. 1978). Bayonove same ~atios in which they had been found in muscat culti­ & Cordonnier (1970 a,b) established that in the case of vars presented a character which corresponded with muscat several muscat cultivars Iinalool is absent in the unripe aroma, but lacked balance. Consequently, the terpene grapes, appears at the beginning of ripening at the same compounds mentioned above do contribute to muscat time as the muscat aroma, increases in concentration aroma, but do not represent the complete aroma spectrum. until maturity is reached and then decreases in concen­ Terpene compounds were also identified in grape tration with over·ripeness. Bayonove & Cordonnier leaves. Wildenradl et el. (1975) reported that pentane (1971) observed increases in concentrations. similar to exlTacts of leaves contained lerpenes and that of linalool, of other terpenes until maturity is their derivatives as prominent compounds apart from reached. Ripe grapes contained about six times more the grassy c:. -compounds. Myrcene, linalool, OC -ter­ linalool. five times moreoe-terpineol, four times more pineol, iso-pulegone, citral, geraniol, nerol and oc- and nerol and 1.4 times more geraniol than unripe grapes, D-ionone were identified. Augustyn & Rapp (1982) fail­ while citral and cilToneUol occurred in nearly the same ed to find measurable concentrations of terpenes in the concentrations in the unripe and ripe grapes. Versini et berries of Chenin blanc. and the question arises whether al. (1981) determined terpenes in Weisser Riesling and which biochemical processes are involved in the grapes during the final ripening period (about one possible lTansiocation of terpene compounds from the month) and observed increases as well as decreases in leaves to the grapes. different terpene concentrations. These studies clearly indicated thai the maximum aroma can be attained Identi fi cation of and dirrerenlialion between cultivars, before all the sugar has been accumulated. using terpenes: Generally, it is difficult to differentiate In contrast to the above-mentioned findings. prelimi­ analyticallY between grape cu1tivars. An exception in this nary investigations (A. Rapp, o. P. H. Augustyn & L. regard is muscat and aroma re lated cultivars, si nce Engel, 1980; personal communication) indicated cultivar-typica1 grape aroma components, such as terpene decreases in the concentrations of certain terpenes of compounds. are quite suitable for the analytical differen­ some muscat and aroma related cultivars in South tiation between some cultivars (Schreier, 1979). Terpene Africa with an increase in grape maturity. Reasons for composition, as well as their concentrations differ between these contradicting tendencies must still be found, but cultivars and are responsible fo r differences in aroma. By may possibly be ascribed to, amongst others, the warm employing mathematical techniques, considerable South African climatic conditions. research has been done in order to identify cultivars and to Wagner et al. (1977), Cordonnier & Bayonove (1978) distinguish between them on the basis of their terpene com­ and Simpson (1979 b) stressed the importance of harves­ position and concentrations. These analyses were useful in ting grapes at the correct maturity. In order to exploit establishing which compounds were cultivar-typicaJ, such the aromatic potential of muscat and aroma related as terpenes, as well as in detennining their effect on the grapes, they should be harvested before maximum sugar quality of grapes and wine (Wagner, Dirningc::r & Fuchs, accumulation. at least before over-ripeness, bUl not too 1974; Rapp& Hasuich, 1976; Schreier, Drawert& Junker, early in order to prevent the detrimental effect of com­ 1976 a; Rapp& Haslrich, 1978 b). ponents derived from unripe grapes on wine quality. Terrier et 01. (1972 b) demonslTated cultivar-typical The optimum maturity of grapes in terms of the optj· distribution patterns of geraniol, nerol, OC-terpineol and mum terpene composition must still be determined. the JinaJool oxides in different white V. vinifera cultivaTS. Schreier el 01. (1976 c) and Drawert & Schreier (1978) suc­ The effect of certain wi ne·maki ng techniques on terpene ceeded in distinguishing mathematically between the concentrations and wine quality: In general, there is cultivars Rul!nder, Morio Muscat, Gewilrztraminer, proportionately higher concentrations of nerol in Scheurebe. Weisser Riesling and Mtlller Thurgau using muscat grapes with small berries compared 10 those with the eoneenlTations of the terpene compounds linaJool, larger berries, such as Muscat d' Alexandrie. Geraniol hotrienoi, geraniol, nerol,oc-terpineol, nerol oxide, the and linalool represent approximately 750/0 to 80% of the rose oxides and the linalool oxides of grapes as well as total terpene content of grapes and wine, and the largest wines. In this case, the rose oxides and nerol oxide emerg­ amounts were fo und in the case of Muscat d' Alexandrie ed as the aroma components with the most significant (Cordonnier & Bayonove, 1978). The volatile compo­ discriminating abilities. Rapp, Hastrich & Engel (1977), nents of the berry are mainly found in the skin and the Rapp & Hastrich (1978 a) and Rapp et 01, (1978) under­ solid parts of the cells. In the case of terpene com­ took detailed investigations into the aroma ("finger­ pounds, Bayonove. Cordonnier & Ratier (1974). print") patterns of different cultivars. By employing the Cordonnier & Bayonove (1978) and Cordonnier & concentrations of certain terpene compounds the authors Bayonove (1981) indicated that in Muscat d' Alexandrie could differentiate between the cultivars Sylvaner, grapes, 94010 of geraniol and 96% of nerol are located in Weisser Riesling and Morio Muscat and the cross B 6 - 18 the skin, whereas Iinalool is almost equally distributed irrespective of grape maturity, year and origin. between the juice (500/0) on the one hand and [he skin More subtle differentiations ("fine pattern") were also (26%) and cellular debris (24010) on the other. Versini possible between Weisser Riesling grapes cultivated in e( al. (1981) found similar trends for geraniol, nerol and different wine areas. citronellol in the ease of Weisser Riesling grapes, name­ ly the occurrence of high concentrations in the skins. The errecl of grape maturity on terpene concentrations: Linalool also occurred in greater concentrations in Several studies were undertaken to determine the effect the skins, namely 60010. The linalool oxides appeared of grape maturity on terpene concentrations in muscat in evenly distributed concentrations between the skins

S. Afr. J . Enol. Yllii:., Yo lo 4. No.2. IIIIl 54 Review: Terpenes in the aroma ojgrapesond wines and the juice plus cellular debris, whereas hotrienol, and geraniol were also increased. Bound terpenes are OC-terpineol and 3,7 - dimethylocta - 1,5 - dien - 3,7- discussed in more depth in the next section. Usseglio­ diol mainly occurred in the juice plus cellular debris. Tomasset (1981) investigated the effect of heat­ Bayonove er 01. (1976) found the distribution of treatment on terpene concentrations of Muscat blanc hotrienoi in Muscat blanc to be 14,5 0/0 in the cmll ular juice and wines, and found decreases in linalool and in­ debris. 30070 in the skin and 55070 in the juice. In other creases in hotrienol, oc-terpineol, nerol and geraniol words, the aromatic profile of the skin differs from that concentrations. Although nuances of the wine-aromas of the juice, and skin-contact may affect wine quality by were modified, the overall quality and aroma intensities affecting the intensity as well as the quality of the were improved. aroma. The Quick removal of juice from the skins in the Ethanol may play an important role in the extraction conventional technique of -making, which is of terpenes from the grape particles (Cordonnier & designed to limit phenolic compounds as far as possible, Bayonove, 1981). Even when present in low concen­ may lead to ignoring of the fact that important aroma trations during , ethanol may act as an components are located in the skin (Cordonnier & Bayo­ extraction solvent. Strauss & Williams (1983) found that nove, 1981) . during the distillation of Muscat d' A1exandrie wine the Different techniques may affect the terpene presence of ethanol caused the formation of linalyl, composition of juice and quality of wines significantly. CX::-terpinyl, neryl and geranyl et·hyl ethers. Generally speaking, pressed juice contains terpene in two to four times higher concentrations than T ransformations of terpene compounds in gl1lPes lind the corresponding free-run juice. Nerol and geraniol wine: It is well-known that transformations of terpenes especially show distinctly higher concentrations in press may take place during the storage of grapes and the pro­ juice than in free-run juice (Cordonnier & Bayonove, duction and maturation of wines. Muscat and aroma 1981). Kinzer & Schreier (1980) compared the effect of related wines may lose their cultivar characters to a large different pressing systems, namely the screw press, the extent during maturation (Wenzel & De Vries, 1968; cylindrical Willmess press and a combination of Lhe Simpson, 1979 a). Vitispirane (Simpson, SLrauss & Willmess press and a chemical pressing-aid material on Williams, 1977) and 1,1,6 - trimethyl • 1,2· dihydro­ the composition of volatile constituenlS in unfermented naphthalene (responsible for the kerosene Oavour, musts and wines. The free-run juice and the press frac­ Simpson. 1978) which are of terpenic origin, were found lions were compared in each case. It was found that, in to develop in Weisser Riesling wines during maturation the case of Morio Muscat musts and wines, concentra­ and affect wine aroma and quality significantly. tions of compounds of cullivar origin, such as terpenes, Terpene compounds in grapes and wines are sensitive increased with an increase in pressure. Sensory evalua­ to acidic conditions and to increases in temperature and tion of the wines were not performed. storage time. Under these conditions they are trans­ Versini et 01. (1981) systematically compared terpene formed to compounds which may be more or less aroma concentrations of Weisser Riesling grapes and the intensive and which may present a different character in corresponding musts and wines. Pressing of the grapes wine (Terrier & Boidron, 1972 a,b; Terrier et 01 .• 1972 increased terpene concentrations markedly from the a,b; Whittaker, 1972). An example in this respect is the grapes to the musts (7-8 times for geraniol, nerol and acid-catalysed rearrangement of nerol and !inalool to a citronellol), as well as in the wines (5-10 times for mutual carbo-cation which could further be stabilised to linalool, nerol, holrienol, ex-terpineol and the furan ex·terpineol, terpinolene and Iimonene. Ribereau­ Iinalool oxides). Furthermore, the authors investigated Gayon et 01. (1975) stated that linalool can easily be oxi· the effect of maceration, which included different con­ dised via an epoxide into four oxides, namely cis- and tact times, a CD,; atmosphere, the use of pectolytic trans- furan Iinalool oxides and cis- and trans- pyran enzymes and heating of the pressed juice on terpene Iinalool oxides. Furthermore, geraniol is transformed concentrations. Although individual terpenes behaved intocx:-terpineol, and nerol, the isomer of geraniol, may differently, generally increases in terpene concentra­ react similarly. Bezzubov et 01. (1980) and Batiashvili et tions were observed. The evaluation of the effects of 01. (1980) discussed the oxidation of terpenes, such as these treatments on wine quality, as well as statistical linalool and geraniol in grapes and wines and found as a correlations of terpenes with wine quality were still in result losses in wine aroma. Castino & Di Stefano (1981) progress at the time of publication. investigated the effect of storage temperature on the Heat-treatment or pasteurisation of grape juice may characteristjcs of Asti Spumante wines and found signi­ have a highly significant effect on the concentrations of fi cant decreases in terpene concentrations of the specific terpenes in the juice and the wines produced wines stored at 20G C, compared to storage at 10°C. It is from it. Bound terpenes in the juice, such as linalool, clear that some of the most intense aromatic terpene hotrienol and cx:-terpineol may be released, and this compounds with low aroma threshold values may be may result in an increase in the concentrations of these transformed into terpenes with high aroma threshold lerpenes. Hotrienol mainly occurs in its bound form in values, and these re-arrangements may result in the loss the juice of the berry and only in small quantities in the of muscat and related aromas during storage of grapes skin itself (Usseglio-Tomasset & Di Stefano. 1979). and wine. Usseglio-Tomasset & Di Stefano (1979) and Usseglio­ Williams et 01. (1980 a) identified four new hydrox­ Tomasset & Oi Stefano (1980) in fact demonstrated gas ylated linalool derivatives in the chloroform extracts of chromatographically that the concentration of linalool Muscat d' Alexandrie grapes and suggested their possi­ doubled, that of iX-terpineol increased eightfold and ble formation from 6,7 _ epox.ydihydrolinalool by that of hotrienol hundredfold after steam distillation of means of a series of enzyme-mediated transformation~. must for one hour at 70"C. The concentrations of nerol Williams et 01. (1980 b) demonstrated the non-enzymallc

s. Afr. J . Enol. Ville., Vol . 4. No.2. 1983 Review: Terpenes in the aroma ojg rapes and wines 55 rearrangements of these four hydroxylated Iinalool It is clear that some terpene compounds which are derivatives at the pH of the grape juice (3,2) to give almost odouriess, may be rearranged during acid- several volatile terpenes. Heating Muscat d' Alexandrie catalysed hydrolysis to yield increases in the concentra- grape juice forift5 minutes at 70"C resulted in an in- tions of existing terpenes as well as the formation of new crease in the concentrations of cis- and trans-furan terpene compounds with quite low aroma threshold linalool oxides, nerol oxide. hotrienol and oc-terpineol. values. The formation of large amounts of certain Simultaneously seven new terpene compounds were terpenes from limited amounts of linalool derivatives identified as grape aroma components. Acid-catalysed could however not be explained. Cordonnier & Bayo- hydrolysis of model solutions of the four bydroxylated nove (1974) suggested that terpenes occur in bound linalool derivatives is illustrated in Figure I forms in muscat grapes, namely as carbohydrate derivatives. However, no terpene glucosides were o, isolated. They believed that under certain conditions during maturation of grapes and fermentation, tbese ",I bound terpenes release additional quantities of volatile 0' terpenes which may contri bute significantly to the muscat aroma. For example. a fraction of ~ s 6 Muscat d' Alexandrie grapes may release linalool by means of enzyme-mediated hydrolysis (Cotdonnier & °' Bayonove. 1974) . Usseglio-Tomasset & Di Stefano (1979) indicated that 0' Iinalool, oc-terpineol and hotrienol mainly occur in o , their bound forms in grape musts. During·fermentation 2 7 8 a modest liberation of terpenes, especiallyoc-terpineol, o, takes place, and increases in their concentrations in wines are consequently observed. Usseglio-Tomasset & Di Stefano (1980) further discussed the existence of 0' bound precursor terpenes and demonstrated ihe trans­ g0' formations of individual pure commercial terpenes to J , other terpenes in an aqueous IOCIJ. alcohol solution, sub­ " jected to heat-treatment at wine pH. h is clear that heat: ~o, treatment of grape juice gives rise to changes in the terpene composition, and oc-terpineol and hotrienol are some of the major products. Di Stefano (1981) deter­ + :IJ-<" mined terpene and terpenoid concentrations in white " " Muscat grapes and mentioned that two-thirds of the *0'• linalool content often occur in the combined form. He also demonstrated reaction mechanisms for the produc­ +n',r\,A tion of Iinalool, cc-terpineol, nerol and geraniol from a linalool precursor. ~ ~H ~~H In the same context, Williams, Strauss & Wilson 13 14 IS (1981) investigated the presence of non-volatile, bound (conjugated) precursor terpenes and volatile free terpenes in Muscat d' Alexandrie grapes. Factors such as temperature and acid hydrolysis induced the re­ arrangement of bound terpenes into free terpenes. Grape juice was extracted with pentane seven times. These pentane extracts contained the free terpenes. The 16 17 pentane-stripped juice was further extracted with Freon FIGURE I II, and this extract contained the more polar, poly­ Acid hydrolysis products of srape polyols 1-4 (Williams, StTalaS & hydroxylated monoterpenes which are also viewed as Wilson, 1980 b). free terpenes; The pentane-freon-stripped juice contain­ I. 3,1- Dimcthylocta - 1,~ - dien - 3,1- diol. ed the remaining highly water-soluble bound terpenes 2. 3,1- Dimethylocta - 1,7 - dien - 3,6 - diol, and this juice, when heated to 70°C at low pH, induced 3. 3,7 - Dimethyloct - 1 - en - 3,6,7 - triol. 4. 3,1 - Dimelhyl(lC{ . I - en - 3,1 - diol. the transformation of bound terpenes into free terpenes. ,. HOlrienol. Some of the major products formed at pH 3,0 were 6. Nerol oxide. hotrienol, linalool. oc-terpineol and the furan Iinalool 1. trans _ Anhydrofuran linalool oxide. oxides. When the pH of the juice was adjusted to I,D 8. cis - Anhydrofuran linalool o~ide. and the juice heated to 70°C, myrcenol and cis- and 9. Irans _ Furan linalool oxide. 10. cis _ Furan linalool oxide. trans-ocimenol were major products. Furthermore, cis­ II. 2,6,6 _ Trimethyl _ 2 - vinyl - tetrahydropyran. and trans - 1,8 - terpin, which had not yet been identi­ 12. 2,2 _ Dimethyl - ~ - (I - methyl-propenyl) telrahydrofuran. fied in grapes and wine, also emerged as prominent 13. Linalool. terpenes. The mechanisms by which these rearrange­ t4. Myrcenol. ments occurred were then not clear. The authors specu­ I ~. cis - Ocimenol. 16. trans - Ocimenol. lated that the different oxidation levels of the terpene 11. OC· Terpineol. compounds possibly played an important role in this

S. Aft. J. Enol. Ville., Vol. 4. No.2. 1983 56 ReviReview: Terpenes in the aroma ojgrapesg rapes and wines regard. InIn view of the presencepresence of bouboundnd terpeterpenesnes aandnd YeastYeastss aarere able to pproduceroduce terpenes. OrawertDrawert & their iinncompletecomplete rearrangemrearrangemenntsts into frfreeee !erpenesterpenes BBartonarton ((1978)1978) demonstrateddemonstrated the formationfo rmation of during different wine-makingwine-making procedures as well as citronellol,citronellol, linalool and geraniolgeraniol by the yeast during extraction procedures of grape juice at normal Kluyveromyces laclislaclis iinn aerobic submmerergedged culture. By juice pH, quantitatquantitativeive resures ullts of tterpeneerpene concentrationsncentrations cchanginghanging ththee c ulture conditions,conditions, the yield of in grape juice and winewiness shshooulduld be interpreted with monoterpenemonolerpenes such as citronecitronellolllol was affected. Fagan, cautioncaution (Williams ef 01.,01 .• 1981).1981). KKepnerepner & Webb (1981) reporeportedrted the production of It became evident from the above-meabove-mentionedntioned researchresearch !inalool,linalool, cis- and transtrans-nerolidol-nerolidol anandd trans, trantrans­s- that concentrconcenlratioationsns of terpeneterpene cocompoundsmpounds andand coconse­nse- farnfaroesolesol by the winewine yeyeastast SaccharomycesSaccharomyces !e!ermentati.rmentati. quently ththee aroma ooff winwine,e, would defindefinitelyitely be affected ThiThiss was ccaarrirrieded out by tthehe yeast growingrowing for 10 weeks by certaicenain wine-making techniques suuchch as heat­heat- as a film oonn the surfaurfacece of a simulatedsimulated fino , treatment of grapesgrapes aandnd mumust.st. which containedcontained ethanoethanol as the only volativolatille carboncarbon WillWilliamiams eett 01.al. (1982 a) confirmed the occurrenceoccurrence ooff contacontainingining compound.compound. bound terpenesterpenes as glucosidcosidicic derivatderivativesives and isolated TerpeTerpene ttransformationsransformations which involveinvolve the actions of

them from grape juice anandd wines by meansmeans ofof Cia­CII - enzymes hhasas been discussed by CroCroteauteau (1975) who bonded reversed-phasereversed-phase liquid chromatography.chromatography. This coconcncludludeded ththat,at, in spitpilee of llimitimiteded knowledk:nowledgege in tthishis type ofof chromatographychromatography allowed separrationation ofof gluco­gluco- respecespect,t, sevseveeralral highlyhighly specific enzymes are involinvolvedved in sidicsidic precursorsprecursors of monoterpenemonoterpeness at differentdifferenl oxidation terpene metabolismmetabolism and transformations. The eenzymenzyme levels. SimultaneoSimultaneously,usly, precurprecursors of the impoimponantrtant nor·nor­ trans- cis-isomerase seemsseems 10to be a key enzyme in terpene isoprenoidisoprenoid grape andand wi ne aroma components, namely metabometabolilism, since it functifunctionsons at the coconditionnditions where vitispirane,vitispirane, 1,1I, I ,6 - trimethtrimethylyl - 1,2 - dihydronapdihydronaphthalenehthalene geranylgeranyl pyrophosphatepyrophosphate iiss transformedtransfonned iintonto cycliccyclic mono-mono­ and damascenonedamascenone werwe re ideidentifiedntified.. WhWhenen the grape juice teterpenes,rpenes, while furtherfurther condndenensationsation to farnesyifarnesyl pyro­pyro- was susubjectedbjected to drasticdrastic coconditions,nditions, namelnamelyy pH 11,0,0 aandnd phospphosphatehate is prevented. AnAnotherother key rreactioneaction in ththee 70°C, the formation of variovariousus tterpeneserpenes,, which havhavee biosynthesibiosynthesis of mmonoterpenesonoterpenes appears to be the not yet beebeenn ideidentifiedntified in grapes and wine, was induced. enzymaticenzymatic dehydrationdehydration ofof oc-terpioc-terpineolneol [to0 terpinoleneterpinolene TheTheyy were amongsstt others 1,4 - cineole,le, 1,8 cineole,cineole, anandd Iimonenelimonene.. oc-Terpineoloc.Terpineol is mmainlyai nly dehydrateddehydrated to oc-oc-teterpinene,rpinene, cis- and trans-ocimenetrans-ocimene,, terpinolene, terpinolene in the case of extracts ooff cacarrotrrot rootsroots anandd to terpinen-l-olterpinen-I-ol and trans- 2,6-dimethylocta -3 ,7.7 - dien .2.-2,66 !imonenelimonene iinn the case of peppermint leaveleaves.s. During the - diol. DiOi Stefano (119982)82) isolaatedted a Iinalool precursor crucrushingshing of ggrapes,rapes, intetensense enzymatic activitieactivitiess occuoccur.r. ffromrom white Muscat of which,which, by acid hydro­hydro- The enzymatic liberationliberation of terpenesterpenes from ssugarugar lysis, mainlmainlyy produced !inaloollinalool andand aarabinose.rabinose. molecules by sppecificecific eenzymes,nzymes , ssuchuch as ft-gjJ-glucosidaselucosidase WilliamWilliamss et uf.al. (1982 b) ideidentifiedntified the glycosidicglycosidic may popossiblyssibly occoccur,ur, which mamayy affect winwinee aroma signsigni­i- precursorsprecursors of the gerageraniolniol oxidation state monoterpenesmonoterpenes ficantly (Cordonnier & BayBayonove.onove, 1981).1981). of both Muscat d' Alexandrie and WWeiseisseserr RiRieslingesling Due to thethe rrelativeelative instabilitabilityty of tterpeneerpene cocompounds,mpounds, grapes and wiwinesnes and tthushus clarified the origin of the free trantransfonnationssfonnations of terpeneterpeness may aalsolso occuoccurr as a result terpenes involvedin volved.. TheTheyy were found to be a compcomplexlex of vvigorousigorous and llengthyengthy extractionextraction proceduresprocedures (William(WiUiamss mixturmixturee of disadisaccharideccharides namelnamelyy jJft •- rutinrutinoossides and et 01.,al., 1980 b). As already mentioned, factorfactorss suuchch aass an 6-0-0c-L-arabinofuranosy6-O-oc-L-arabinofuranosyl - ftjJ-O-glucopyranos· D-glucopyranosideidess of increaseincrease in temperature anandd acid condiconditionstions resultresult in several monoterpemonoterpenene alcohols. These findingfi ndingss were marked iincreasencreasess in tthehe concentratioconcentrationns of sosomeme existing confirmed by hydrolyhydrolysisis studietudiess of synthetintheticc nnery!ery!,, gera­gera- teterpenesrpenes as well aass the formation of new terpterpeneene cocom­m- nyl and Iinallinalylyl jJ-D-ft- D- g1ucopyranosidesgl ucopyranosides (Williams et uf.aI. , pounds. In ootherther words,words, tterpeneserpenes may a1soalso be produced 11982982 c).cj. aass aartefactsrtefacts which conseqconsequentlyuently do nolnot reprerepresentsent the Boidron (1978) investigatedinvestigated the effect of BQtryiisBotry/is originaloriginal aaromaroma profilepronJe of grapes and wine (Usseglio­(Usseglio- cinereacinerea infinfectionection onon the decomposition of tterpeneerpeness in TomassetTomasset & DiOi SteStefano,fan o, 1979; Williams et 0/"al., 19198080 b). grape juicejuice and found decreases in the concentrationscentrations of MoreMore accuaccuratratee and mild isolationisolation techniquess,, suchuch as linalool,Iinalool, ccex: -tterpineol,erpineol, geraniol, nerol, hotrienolhotrienol and heheadspaceadspace methods, which involveinvolve the sasamplingmpling and terrpenepene oxidationoxidation productproductss, as well as an eventual diss­- coconcentrationncentration of aroma cocomponentsmponents in the headspacepace appearance of tthehe majoritymajority of the terterpenepene cocompoundsmpounds aboaboveve wines,wines. appear to be the most acacceptable.ceptable. TThesehese and ththee didistinstinct muscatmuscat aroma withwith an inincreasecrease in infec·infec­ ttechniqueechniques sho shoulduld produceproduce aann aroma profilprofilee which is tiontion.. SShimizu,himizu. UehaUeharra & WatanWatanabeabe (1982) demondemon­- mmoreore reprerepresentativesentative of tthosehose volatiles of grape juice and strated the trantransformationssformations of someme monoterpenes to winewine whicwhichh actually eententer ththee nose when ththee product is ototheherr {erpenesterpenes when added to artificiallyanificial1y botrytized being ssmeltmelt (William(Williams,s, 119982).82). Rapp & KnipserKnipser (1980) ggraperape must. The concentrntrationation of a mmixtureixture of cis- and described a method for the enricenrichmenthment of hheadspaceeadspace ttrans-furanrans-furan linallinaloolool oxox.iidedess remainineded unchangechangedd, cocomponentsmponents of wine in which tthehe mild coconditionsnditions whewhereasreas tthehe coconcentrationcentrations of !inalool,linalool, terpinenterpinen - 4 - 01 ininvolvedvolved prevent thethe formation of artefacts as far as and oc -terpineolterpineol decreased markedly. When oonlynly practically pospossible.sible. !inalool was added to ththee mumust,st, 1122 tterpeneerpeness were ReResearcsearch indicateindicatess clearlyclearly that terpeterpenene compoundscompounds produced.produced. TheyThey were ft-jJ-pinene,pinene, cis- and trans-furantrans-furan are responsibleresponsible forfor some of ththee mostmost importantimportant and linaloollinalool oxides, p-menthane-p-menthane-ll-en-3-o-3-onne,e, oc-terpineooc-terpineol, pprominentrominent aromaaromass in grapes and winewines.s. TTechnologicalechnological ccisis-- and transs-pyran-pyran !inaIinaloolool oxides, geraniogeraniol,l, development of analyticalanalytical instruments make it possible p-menthane-l,8-dien-9-olp-menthane- I,8-dien-9-01 and thrthreeee unidentified to gaingain deeper insiightght int intoo the nature ofof terpenesterpenes.. monoterpenes. When oonlynly terpinen - 4-01 was adaddedded to FacFactotorrs suchuch as cultivar,cultivar, climatic conditions, grape the[he must, only one teterpene,rpene, nanamelymely gerageranial,nial, was maturity,maturity, pH,pH, enzymes,enzymes, lenlengthgthyy sstoragetorage times, extraextrac­c- produproducedced.. BotrYlisBotrytis cinerea did nnotot produproducece terpene tion procedproceduresures and wine-making procedures ssucuchh as comcompoundspounds in grape must llackinackingg tterperpeneenes. mamaceration,ceration, heatheat-treatment-treatment anandd prpreessssiningg may hahaveve a

S. Afr. J. Enol. Vitic, Vol. 4. No. 2. 1983 Review: Terpenes in (he aroma 0/grapes and wines 57 significant effect on the volatile terpene content of DI STEFANO, R., 1982. Presenza di precursori del linalolo nel grapes and wines and on wine quali ty. By improving Moscato bianco del Piemonte. Vign;vini IX, 45-47 . Quantification of terpenes, and utilisation of available DRAWERT, F. & BARTON. H., 1978. Biosynthesis or Oavor com­ pounds by micro-organisms. 3. Production of monoterpcnes hy knowledge, the adaptability of different cultivars to the yeast KluperomJCeS IQClis. J. Agric. Food Chem. 26, 76S -766. different climatic regions may be utilised better, and DRAWERT, F. & SCHREIER, p .. 1978. Caracterisation des raisins high quality wines with more specific aroma styles may ct des vins il. I'aide de ~rtains constituants remarquables. Ann. be produced. Technol. Agric. 27. 367-3". FAGAN, G. L .. KEPNER. R. E. &; WEBB, A. D.• 1981. Production linalool, cis- and traru_nerolidol, and tran$, trans-- farnesol by LITERATURE CITED Socchorornyets jermenlQti growing as a film on simulated wine. 20, 36-42. AUGUSTYN, O. P. H. & RAPP, A .. 1982. Aroma tomponems of HARDY, P . J .. 1970. Changes in volatiles of muscat grapes during Vitis I>lnilefQ L. tv. Chenin blanc grapes and their changes ripening. Phytochemistry 9, 709-715. during maturation. S. Afr. 1. Enol. Vitlc. 3,47-51. KINZER, G. &r: SCHREIER . P., 1980. Innuence of different press ing AUSTER WElL, G., 1946. Quelques ob~e rvation s sur les parfums des systems on the composition of vo lalile constituents in unfer· vins. Ind. PUf/urn . I , 19!1-199. mented grape muslli and wines. Am. 1. Enol. Vitir.. 31, 7-1] . BATIASHV ILI, T.A., BEZZUBOV. A. A., CHICHASVILI, N. D. KLOUWEN, M . H. & TER HEIDE, R., 1962. Studies on terpenes. &r: ROOOPULO, A. K., 1980. Changes in the essential oil I. A syst~matic analysis of monoterpene hydrocarbons by gas­ compositions of grapes during their treatment (for wine). Prilcl. liquid chromatography. 1. Chromo 7, 297-3 10. 8iokhim. Milcrobiol. 16, 609·611. (Chem. Almf. 93 (13), MEILGAA.RD, M. C., 1975. Flavour ehemistry of beer: Part 11 ; 2361147c, 1980). Flavour and threshold of 239 aroma volatiles. Tteh. Q. Muster BAYONOVE, C. & CORDONNIER , R., 1970 a. Recherches sur Brew. AssO£'. Am. 12, 1S1 - 168. l'arOme du muscat. I. Evolution des cOD!lituants volatils au NOBLE, A . C., FLATH, R. A. & FORREY, R. R., 1980. Wine cours de la maturation du Muscat d'Alexandrie. Ann. Ttchno/. headspace analysis. Reproducibility and application to AIr/C. 19, 79-93. classification. 1. Agfic. Food Chern. 13. ]46-353. BA YONOVE, C. &r: CORDONNIER, R., 1970 b. Recherches sur PINDER, A. R., 1960. The chemistry of the terpenes. Chapman &. l' arOme du muscat. 11 . Profils aromatiques de ct-pages muscat et Hall. LTD London. non mU!iCat. Importance du !ina.lol chez les musC8ts. Ann. PR1LLlNGER, F. &r: MADNER, A .. 1970. Di e Ollchtigen Inhalts-­ T«hnol. Agr/c. 19,95·105. stoffe von Muskatmoslen und-weinen. Milt. Klosterneuburg. 211. BA YONOVE, C. & CORDONNIER, R., 1971. Recherches sur 202-205. l'arOme du muscat. III. ~tude de la fraction terptnique. Ann. RAPP, A. &. HASTRICH, fl., 1976. Gaschromatographische Unter­ Ttchnol. Agric. 10,247-355. suchungen ObeT die Aromasloffe von Weinbttren. II. MOglich­ BAYONOVE, C. , CORDONNIER, R. & RATIER, R., 1974. lI:eiten der Soru:ncharakterisierung. Viti!; IS, 183-192. Loca.lisation de l'arOme dans lit baie de raisin ; varietes Muscat RAPP, A., HASTRI CH, H. & ENGEL, L .. 1977. KapUiarchroma­ d'Ale:nndrie el Cabcmet Sauvignon. C. R. seonces; Arod. tographische Untersuchungen IIbcr die Aromastoffe von Wein Agri". Fr. 60, 1321-1328. und Weinbeeren. MOgiich keitcn rur Sortencharakterisierung. Mitt. K/oslemeuburg. 27, 74-82. BA YONOVe, C. , RICHARD, H. &r: CORDONNIER, R.. 1976. & l~olement ct identification du dimethyl -3.7 octatri~ne - 1.5 .7 RAPP, A. HASTRI CH. H., 1979 a. Gaschromatographische 01 -3 ou Irans hotrienol, constituant a odeur de Tilleul de I'huile Untersuchungen llber die Aromastofle von Weinbeeren. Ill. Die euentieUe de Muscat de Frondgnan. C. R. A"ad. Sc. PQris, Sir. Bedcutung des Standortes fllr die Aromastoffzusammensetzung C. 2!J, !l49-!l!l1. der Rebso rte Riesling. Vitis 17, 288-298. RAPP, A. & HASTR1CH, H., 1978 h. Application de la chromato­ BEZZU80V, A. A., RODQPULO, A. K.• EGOROV, I. A. &; graphic en phase gazeuse 11a caracterisation des varietts. Ann. NECHAEV, L. N .. 1980. Aroma-fonning subSianCt5 or grape hybrid varietie5 and wines produced from them. Prilcl. Blokhim. Ttehnol. AIr/C. 27, 423-426. Mlkrobiol. 16, 120-126 (Chem. Abstf. 92 (12), 19630Sv, 1980). RAPP, A., HASTR1CH, H ., ENGEL, L &; KNIPSER, W., 1978. "Flavor of foods and bevera8es". Possibilities of characterizi ng BOIDRON, J. N., 1979. Relation entre le5 5ubstan~es te~niques et wine quality ilIId vine varieties by means of capillary chromato­ la qualit ~ du raisin (ROle du 801",1i!; cinereQ) . Ann. Technol. graphy. Academic Press, N.Y., S.F. Lond. 391-417. Agfie. 27, 141·]4!1. RAPP. A. &. KN IPSER, W., 1979. 3,7 - Dimethyl-okta-I,S-dien- CASTINO, M. & 01 STEFANO, R., 1981. Erretti della temperatura 3,7-diol --cine neue tcrpcnoide Verbindung des Trauben- und di conservazione $ulle caratterisliche delJ'Asti Spumante. Riv. Weinaromas. Vilis 18, 229--233. Vitie. Enol. 34, 1 ~119. RAPP, A. & KNIPSER, w.. 1980. Eine neue Methode zut Anreiche­ CORDONNIER, R., 1956. Recherches sur i'aromatisation et Ie rung von Dampfkomponenlen. Dargesielt am Beispiel dC$ parfum de vins doult naturels et des vi ns de liqueur. Ann. fn st. Wcines. ChromQtogrQphiQ 13,698-702. NQ1I. Rteherches AKron. ser. E. Ann. Ttehnol. Agrie. 5, 75·110. CORDONNIER, R., 1974. L'arOmedes vins. Progf. Agrie. Vitic. 91. RAPP, A .. KNIPSER, W. & ENGEL, L .. 1980. Identifizierung von 320-329. 3,7-Dimelhyl-okla - 1,7 - dien - 3,6 - diol im Trauben- und Wein· aroma von Musll:atsorlen. Vitis 19, 226-229. COROONN IER , R. &r: SA YO NOVE, C., 1974. Mise en evidence dans la baie de raisin, varihe Muscat d' Alellandrie. de monoterpblcs R1B'::REAU-GAYON, P., BOH':WN. J. N. & TERRIER, A .. 1975 li es revela bles par une ou plusieurs enzymes du fruit. C. R. Acad. Aroma of Muscat grape varieties. 1. Agrle. Food Chern. 2.1. 1042-1047. &. Paris, ~r. D. 173, 3387-3]90. CORDONNIER, R. & BA YONOVE, C .• ]978. Le5 composantcs SCHREIER, P., 1979. Flavor composition of wines: a review. CRC varihales et prefermentaires de l'atOme des vins. £;ClrQil de Crit. ReI>. Food Sci. Mm. 12,59· 111 . PQrjum Cosm~liqul'!S Qraml'!S. 24. 67-77. SCHREIER, P. &. DRAWERT, F., 1974 a. Gaschromatoglaphisch­ CORDONNIER. R. & BAYONOVE, C .. 1981. ttude de la phase masscnspektrometrische Untersuchu", nuchtiger Inhal1sstoffe prefennentaire de la vinification: Extraction el formation de des Weines. 1. Unpolare Verbindungen dc~ Weinaromas. Z. certains composes de l'arOme; cas des terpenols, des aldehydes et Leben.srn. Unters.-Fof$eh. 150$,273_278 . des alcools en C,. ConnaW. Vigne Vin . 15,269-286. SCHREIER. P. & DRAWERT, F., 1974 b. GaKhromatographisch­ CROTEAU, R., 1975. Biosynthesis of monolerpenes and ma55enspektrom e !ri~che Unl~ r~uc h ung OUchliger InhahsstoHe sesquiterpenes. Gerueh- und Gcchmackstoffe. Verlag Hans des Wcincs. V. Alkohole, Hydrolty-, Lactone und andere Carl NQrnbcrg. 1S3-166. polare Komponenten des Wei naromas. Cht'm. MikfObiol. DEVON, T . K. & scorf, A. I., 1972. Handbook of naturally Technol. Lebensrn. 3, U4-160. occurring compounds. Volume II. Terpcnes. Acndemic P~s, SCHREIER, P., DRAWERT, F. & JUNKER. A., 1974. Iden ti­ New York . fizicrung von 3,7· Dimethyl - 1.5 ,7 _ octatrien-3-o1 al s Ouch!ige DI STEFANO. R., 1981. Terpene compounds of white Muscal from Komponcnte des Trauben- und Weinaromas. Z. Lebensm. Piemonte. Vini. fUll. 2.1. 29--43. Unlers.-Fof$eh. ISS, 98-99.

S. Mr. J . En ol. VJtlc .. Vu l. 4. Nu. Z. 1911J 58 Review: Terpenes in the aroma oj grapes and wines

SCHREIER, P., ORAWERT, F. &: JUNKER, A .• 1976 •. USSEGLIO-TOMASSET, 1.. I/: DI STEFANO, R., 1980. Profilo Gas<:hrom.tosr.phiKh - mauenspc ktrometrischc: Dirrc:r~e­ Iromltko del Moscato bianco del Piernontt. Ri~. Vitie. Enol. fUll' der TrtubenaromutOrrc verschiedcner Rebsonen von Vilis 3J,51-68. vini/ertJ. Chem. Mikrobiol. T«hnoJ. uknsm. 4. 1S4.1!i1. VAN STRATEN, S., DE BEAUVESER, J . C • .t. VISSCHER, C. A. SCHREIER, P., DJtAWERT, F. a: JUNKER, A., 1976 b. Identt. 1m. "Volatile Compounds in Food", Supplement 5 (1980, lielljon of vohulle conllilUl'nll from ,rapes. J. Agril:. Food wint), 10.1 ·70.9 and Suppkment 6 (l981, ,",pe) 9.1-9.6 to!ht Chern . 14. JlI·))6. Fourth Edition. Ctntrll Institute for Nutrition and Food SCHREIER, P., DRAWERT. F .• JUNKER, A.. a REINER, L. I976c. Reso:arth TNO, leist, Tht Netherlands. Anwendun, der multiple" OiskriminllJ1UJlal)'5e zur Dirreren­ VERSINI, 0., INAMA, S. I: SARTORI, G .. 1981 . A capillary lierun& von Rcb50rtm lfl Hand de.. qUlnlitltiven Vertei1UII, tolumn luehromatogrlphic reseafch into tht terpene nllchli,eJ Wrininhah.SSlOrre. Mitl. KIOSlernewk". 26. 225-234. constitueDt! of "Rieslinl Rtnano" (Rhint Rieslina) wine from SCHREIER, P., DRAWERT, F. &: JUNKER, A., 1977. Gaschro­ Trentlno Alto AdIIC: Their dislribution within berries, their matographische Best immun. der lnhaltsstoffe von Glrunpge­ passale into mini and !heir prestnce in the wine accordina 10 trlnken. X. Quantitative Bestimmu", von Weinaromaslorren in different wine-mllt:inl procedures. Organokptlt considmtions. myall-Bereich. Chern . Mikrobiol. T«hnol. ubensm. 5, 4S-S2. VinIIIQI. XXIII, 189-21 1. SH IMI ZU, J., UEHARA. M. &. WATANABE, M., 1982. Trans­ WAONBR, R., D1RNINOER. N. It FUCHS. V., 1974. Rbiultau formation of terpenoids in afape must by BOlrylis eintrtQ. pr~lImlnalrel concernant I '~t ude I~nttique de substanc:eJ A,rie. BioI. Cheln. 46, 1339-1344. odorantes dkelbes par ch rOmatOifaphit tn phase gauuSf: dans SIMPSON, R. F., 1978. 1,1,60Trimtthyl· I,2-dihydronaphthaiene: les fruitl d'unt descendance de Vilis ~iniftrQ 1.. Colloque C.N.R.S. "Facttuf3 tl ngillation dt IQ mQluril1 des fruits". lli Impertanl contributor to the boult aled bouquet of wIne. Chern . Ind .. 37 . 335·J39. WA GNER, R .. D1RNINGER, N., FUCHS. V. &: BRONNER, A., SIMPSON. R. F .• 1979 a. Aroma tompesition of bottlt agtd white Study or the in letVarietal differ-ences In Ihe concentration wint. Vilis II. 148-15-4. 1m. of vola tilt constituent! (Ilnalool and geraniol) in the aroma of SIMPSON, R. F., 1979 b. Some Important aroma components of the Ifape. Intertst of tuth anaJyxs for the appreciation or the whIte wine. Food T«lIl1ol. AIISI. Jl, 516--522. quality or Ihe . Int. S,mp. QuQI. VinlllJt. Cope Town. SIMPSON. R. F., STRAUSS, C. R . .t: WILLIAMS, P. J., 1971. 131·142. Vitispirane: • CIl splro--ctba- In tht aroma volatiles of &rape WEBB, A. D_ I/; KEPNER, R. E .. 1957. Somt volatile aroma juice, wines and distilled pape spirits. Chtln. Ind., 66~ . constitutnts or Vitls ~in/ftl'fJ YIJ'. "hue.1 or Alallidria_ Food STEVENS. K. L .. BOMBEN. J., LEE. A . .t: McFADDEN. W. H " Res. n. J84-39S. 1966. Volatiles from &rapes. Muscat of Alexllidria. J. A,ric. WEBB, A. D., KEPNER, R. E . .t. MAGG10RA, 1.., 1966. Gas ehro­ Food Chtln. 14.249-2$2. matOVlphit tomparUon of yoialilt aroma materials extracted STEVENS. K. L" 8OMBEN. J . .t. McFADDEN. W. H .• 1961. rrom dJht different muscat· navored varieties of Vitis yjn/fera. Volatiles from Jflpes. Vilis vin/ftra (LiDD.) cuillvar Grtnache. Aln. J. Enol. Vltlc. 17.247·254. J. Agrie. Food CMm. IS. H8·3&o. WENZEL, "- W. O . .t: DE VRIES, M. J., 1968. An inytsligllion STRAUSS. C. R . .t: WILLIAMS, P. J .• 1983. The dfo::a of distillation or mus-cat aroma. S. AIr. J. Alfie. Sci. 11 ,273·280. on Jflpe navour components. F/QVOlir of Dislil/ttl /kYerages WHllTAKER, D., 1972. Tht monotCT'pt'Des. Newmln. A. A. ed. Symp. 1-4th Jllnt. Univ. of Stirling. Scotland, U.K. CheminI'} or ttrpo:nes and Itrpenoids_ Acadtnlic Prc:u, London, TER HEIDE. R .. 1968. Studies on Itrpcne5. II. Characterization of 11·81. monoterpene esten b, lIS and thiJI..layer ehromatOlraphy. WILDENRADT, H. L., CHRISTENSEN. E. N., STACKLER, B .. Z. AnQI. Chtm. l36. 215-227. CAPUTI, Jr.. A., SLINKARD, K. .t: scurr, K., 1915. Volatilt TER HEIDE, R., 1976. SU.ld ies on terpenes. III. GIS chrom.tography constitucnts of lrape leayes. I. Viris vinif~ra yariely 'Chenin of acycHt monoterpene alcohols. J. Chromo 129, 143· 154. blanc'. Am. J. Enol. Vii/(:. 26, 148·153. TERRIER, A. &. BO IDRON, J. N., 1912 a. Identification des derives WILLIAMS, A. A .. 1982. Recent dtYelopmenu in the field of wine te r~n lques dans les raisins dt certaines varittes dt Vilis vln/fera. flavour rtsearch. J. Inst. arew. 1111, 43·53. I. Techniques expmmtntales. ConnQw. Vignt Vin. 1,69-85. WILLIAMS, P. J., STRAUSS, C. R. &. WILSON. B., 1980 a. New TERRIER, A . .t. BOIDRON, J. N., 1972 b. Identifiallion dts linalool derivatlyes In Muscat or Alexandria grapel and wines. derives tt'f'l)tniqucs dans les raisins de certaines yarietbi de Vltis Phytoch~misrry 19,1137· 1139. ~inifera. II . Rcsultat!. ConnQw. Vi,nt Yin. 1, 141- 160. WILLIAMS, P . J., STRAUSS, C. R. 4 WILSON, B.. 1980 b. TERRIER. A., BOIDRON, J. N . .t. RIBtREAU..

S. Afr. l . Enol. Vide .. Veil . 4. No.2. 1983