Journal of the Science of Food and Agriculture J Sci Food Agric 85:2040–2046 (2005) DOI: 10.1002/jsfa.2214

Terpene profiles in Cantal and Saint-Nectaire- type cheese made from raw or pasteurised milk† Agnes` Cornu,1,2∗ Nathalie Kondjoyan,1 Bruno Martin,2 Isabelle Verdier-Metz,3 Philippe Pradel,4 Jean-Louis Berdague´ 1 and Jean-Baptiste Coulon2 1Unite´ de Recherches sur la Viande, INRA de Theix, F63122 Saint-Genes` Champanelle, France 2Unite´ de Recherches sur les Herbivores, INRA de Theix, F63122 Saint-Genes` Champanelle, France 3Unite´ de Recherches Fromageres,` INRA, 36 route de Salers, F15000 Aurillac, France 4Domaine de Marcenat, INRA, F15190 Marcenat, France

Abstract: Terpene profiles in cheese can be considered a ‘terroir’ fingerprint as the information contained in it should enable the pastures on which the animals were fed to be recognised. Yet a certain elasticity of the signature must be taken into account when determining authentication strategies, since products acknowledged as containing a common signature may have undergone certain procedures, such as cheese making and milk pasteurisation, that could have potentially altered their terpene profiles. In this study, Cantal and Saint-Nectaire-type cheeses were made from both raw and pasteurised milk from the same herd of dairy cows that had been grazed on natural grassland. Cheeses from raw and pasteurised milk weremadefromthesamemilkingonthesamedays.Cantal and Saint-Nectaire-type cheeses were made on 4 different days, alternatively over four weeks. The terpenes in the cheese fat were analysed by dynamic headspace/gas chromatography/mass spectrometry. A great diversity of monoterpenes, sesquiterpenes and oxygen-containing derivatives were identified. The major terpenes identified in most cheeses were β-caryophyllene, α-andβ-pinene and limonene. Milk pasteurisation did not induce changes in the terpene profile of the cheese. Significant differences (p < 0.001) were observed between Cantal and Saint-Nectaire cheeses: α-pinene, β-myrcene and β-phellandrene were, respectively, three, five and five times more abundant in Cantal cheese, while tricyclene, α-phellandrene and geraniol were found exclusively in Cantal cheese. In contrast, unidentified sesquiterpenes with retention indices (KI) = 1342 and 1511, α-cubebene, longifolene and γ -elemene were more abundant or exclusively found in Saint-Nectaire cheese. A significant relationship with the date of milking (p < 0.01) was observed for α-pinene and tricyclene in Cantal, for β-myrcene, δ-3-carene, p-cymene and α-terpinene in Saint-Nectaire cheese.  2005 Society of Chemical Industry Keywords: terpene; animal food; milk; cheese; traceability; pasture; pasteurisation

INTRODUCTION diets could be traced through the sesquiterpenes Terpenes are plant secondary metabolites that are found in cheese. Milk and cheese produced on ingested by herbivores and subsequently found in pastures with highly diversified botanical composition associated milk and meat. Forage terpene content have been shown to differ significantly in their varies greatly according to the plant species. It is either terpene content from those obtained on monospecific absent or very scarce in cultivated grassland plants grassland.5–7 Likewise, milk obtained from natural such as Poaceae or legumes, and greater amounts and pasture contained approximately ten times more range of monoterpenes, sesquiterpenes and oxygen- terpenes than milk obtained from the corresponding containing derivatives are found in some dicots of hay.8 Terpene analysis enabled the discrimination permanent grassland.1–3 The terpene fingerprint of a between milk obtained from pastures located in given grassland results from the range of plant species different geographical areas, in both milk9,10 and and is also dependent on the soil, climate, geographical meat.11,12 localisation and grassland management practices. As a measurable component of the terroir-to- Back in 1978, Dumont and Adda4 underlined that product linkage, the terpene fingerprint could help in seasonal or geographical variations of dairy cow delimiting areas for Protected Denomination of Origin

∗ Correspondence to: Dr Agnes` Cornu, URH DIMA, INRA de Theix, F63122 Saint-Genes` Champanelle, France E-mail: [email protected] †This work was partially presented at the 5th Intl Meeting on Mountain Cheese, Areches,` France, 2003 Contract/grant sponsor: AQS program (Received 24 February 2004; revised version received 3 September 2004; accepted 17 February 2005) Published online 6 June 2005  2005 Society of Chemical Industry. J Sci Food Agric 0022–5142/2005/$30.00 2040 Terpene profiles in Cantal and Saint-Nectaire-type cheese

(PDO) products, and to verify that specifications curd was cut for 5 min to produce grains 5–6 mm in concerning animal feed have been fulfilled. The diameter. The curd–whey mixture was then mixed for information contained in terpene profiles, however, 12 min and left to stand for 7 min. After extraction is far from being completely understood. Most of the of the whey, the curd was placed into a pressing tray observations collected until now have to be confirmed where it was pressed, cut into 15-cm cubes, and turned under experimental conditions, to allow the separate 12 times for approximately 3 h in order to reach 50% factors that potentially affect terpene profiles to be dry matter. After pressing, the curd cubes were left controlled: eg pasture management and location, to drain for 24 h at 20 ◦C and were pounded into specific herd of cows, cattle management, cheese- grains 20 mm in diameter. The mixture was salted making technology, profile of plants. with 20 g kg−1 dry salt and left to stand for 6 h at The objective of the work presented here was 20 ◦C before one cheese per vat was formed in a cloth to study the separate effects of two technological mould and pressed for 24 h at 13 ◦C. The cheeses were factors that can affect the terpene fingerprints placed in a ripening cellar at 10 ◦C and 95% minimum transmitted from the grassland pasture to the relative humidity. mature cheese: milk pasteurisation and cheese-making Raw and pasteurised Saint-Nectaire cheeses were technology. Two varieties of PDO-labelled cheeses manufactured in two vats, each containing 32 kg of originating from Auvergne (France), Cantal and Saint- milk heated to 33 ◦C. The vats of milk were inoculated Nectaire cheeses, were produced with experimental with a lyophilised mesophilic and thermophilic facilities from either raw or pasteurised milk of the starter culture (respectively 0.1gkg−1 of MA400 same milkings. and 2.35 g kg−1 of MY800, Texel, Dange-Saint-´ Romain, France) reconstituted in sterile skimmed milk (100 g l−1), with a ripening starter (7 × 106 germs −1 EXPERIMENTAL l , Groupement d’Inter´ etˆ Economique, Laboratoire Cheese making Interprofessionnel de Production, Aurillac, France) −1 −1 Sixteen Montbeliarde´ dairy cows were used; these and 33 g kg of a 520 mg active chymosin l had been grazed on natural grassland at the INRA rennet (Gand-Gassiot, France). The composition of Experimental Center of Marcenat (Cantal, France). the starters were as follows: MY 800: Streptococcus The milk was collected in the evening and stored salivarius spp thermophilus, Lactobacillus delbrueckii spp overnight at +4 ◦C, mixed with un-refrigerated lactis and Lactobacillus delbrueckii spp bulgaricus;MA morning milk and immediately transported to the 400: Lactococcus lactis spp lactis, Lactococcus lactis spp INRA experimental dairy plant at Aurillac (Cantal, cremoris, Lactococcus lactis spp lactis biovar diacetylactis France) within approximately 1.5 h. Half of the milk and Streptococcus salivarius spp thermophilus.The was left raw whilst the other half was pasteurised for clotting time was assessed visually and lasted for 30 s at 72 ◦C. Raw-milk cheese and pasteurised-milk around 1 h, after which the curd was cut for 3 min, cheese were processed on the same cheese-making stirred for 6 min and left to stand for 4 min. The curd days, whereas the two varieties of cheese were made was separated by using a grille and the whey was on different days: Cantal cheese on June, 5, 14, 18 drained off. The curd was cut into 24 cubes to further and 21; and Saint-Nectaire cheeses on June 7, 19, 26 extract the whey. These cubes were then placed into and 29. Overall, 16 cheeses were used for this study: two moulds to shape in a moulding machine (Duprat, they were 2 varieties of cheese ×2 milk treatments ×4 France). Each cheese was rolled in a cheese cloth and replications. hoop, salted on the surface (40 g NaCl a side) and For the experiment requirements, smaller Cantal placed in polypropylene moulds. These cheeses were cheeses (10 instead of 40 kg), ‘Cantalets’ (also PDO pressed for 24 h under 3 bars, then ripened in a cellar ◦ authorised), were manufactured from 110 l of milk. at 10 C and 95% minimum relative humidity. Once heated to 33 ◦C, both raw and pasteurised milk Samples of Saint-Nectaire cheese were taken after were inoculated with 0.2 g of a lyophilised mesophilic 44 days maturation and Cantal cheese samples after starter culture (Flora Danica Direct, Sochal, Saint- 123 days. These samples (about 100 g) were wrapped Etienne-de-Chomeil, France) reconstituted in sterile in aluminium foils, sealed in polyethylene bags skimmed milk (100 g l−1), with a ripening starter under reduced pressure with a vacuum seal machine (2 ml of Monilev and 1.5 ml of Penbac, Laboratoire (Multivac, F77462 Lagny sur Marne) and stored at ◦ Interprofessionnel de Production, Aurillac, France) −20 C. and 0.33 g kg−1 of a rennet containing 520 mg of active chymosin/per litre. The compositions of the Terpene analysis starters were as follows: Flora Danica: Lactococcus Fat was recovered as a supernatant after centrifuging lactis spp lactis and spp cremoris 75%, Lactococcus 40 g of cheese for 2 h at 75 600 × g at 25 ◦Cina lactis spp lactis biovar diacetylactis 20%, Leuconostoc Beckman Avanti J-301 centrifuge (Fullertown, CA mesentero¨ıdes spp cremoris 5%; Monilev: Moniliella 92 834-3100, USA). Terpenes were extracted from 2 × 109 l−1; Candida famata 6.25 × 1011 l−1; Penbac: 0.2 g of fat by dynamic headspace (DHS) using an Brevibacterium 4 × 1013 l−1, Penicillium nalgiovensis automatic Tekmar LSC 2000 system (Cincinnati, OH 4 × 1010 l−1, Micrococcus. Forty-five minutes later, the 45 234, USA). The fat was deposited on 0.15 g of

J Sci Food Agric 85:2040–2046 (2005) 2041 ACornuet al glass wool in a 40-ml cylindrical glass extractor (Ets detected in the 16 samples: 23 monoterpenes of which Mailleres` Freres,` Aubiere` 63 170 France) maintained 4 contained oxygen (Table 1); 28 sesquiterpenes of at 110 ◦C. Volatile compounds were purged for 30 min which one was esterified and one contained oxygen by a helium flow of 90 ml min−1,trappedonTenaxat (Table 2). In most cheeses, the major terpenes were 28 ◦C, desorbed by heating the trap for 5 min at 220 ◦C β-caryophyllene, α-pinene, β-pinene and limonene in and cryofocused in the GC column head at −150 ◦C which β-phellandrene co-eluted in several samples. with liquid nitrogen. Molecules were separated and When available, variation ranges were between 100 identified by GC-MS using a SPB5 Supelco capillary and 500% in most cases and over 1000% in five column as previously described,7 except that the GC cases, all of them observed for Cantal cheese. The program was continued until the oven temperature highest variation ranges were not necessarily associ- reached 230 ◦C. Terpene peaks were located on ated with the terpenes detected in trace amounts, the chromatograms by the means of their specific as would be expected if variations originated in the mass fragments: 93 and 136 for monoterpenoids, analysis method. 93, 136, 161, 204 for sesquiterpenoids. They were No significant difference in the amount of individual identified by comparing the experimental mass spectra terpenes desorbed from the cheese fat was found and retention indices (KI)13 with those contained between cheeses made from raw or pasteurised milk. in published databases.14– 16 Semi-quantification was The most significant probability found was 0.06 for an achieved by integrating the ion current of the unidentified ester at KI = 1386. mass fragment 93 for monoterpenoids and 161 Differences were observed between Cantal and sesquiterpenoids. The results were expressed in Saint-Nectaire cheeses. Higher quantities and a greater arbitrary area units. diversity of terpene compounds were found in Cantal Median terpene values were used in preference cheese. The major terpene was α-pinene in all the Can- to their means in accordance with Feinberg and tal cheese samples, whereas in all the Saint-Nectaire Ducauze17 who stated that they were better adapted cheese samples it was β-caryophyllene. Several ter- for analytical data with potentially dissymmetric pene molecules were found to be significantly different distributions. The median, rather than the mean, (p < 0.001) in the two varieties of cheese: tricyclene, represents the central value of a data set and is α-pinene, β-myrcene, limonene + β-phellandrene, less sensitive to aberrant values. Variation ranges over geraniol, the unidentified sesquiterpene at KI = 1342, groups of four cheeses were calculated as follows: α-cubebene, longifolene and γ -elemene.

= × − Var% 100 (max value min value)/median Abundance (10-5) 3 8 Where terpenes were found in only one of the four cheeses they had no median and their variation range could not be calculated (×/0). 2 7 Statistical analyses 1 6 10 Data were analysed using Statistica 5.5 (Statsoft, Paris, 5 12 France) software. The effects of milk treatment and 1 the variety of cheese on the amount desorbed for each terpene were assessed using the ANCOVA test. The 30 35 40 45 50 55 6 model was: (a) min Abundance -5 Xi = µ + Pi + Cj + (covar date) + Pi × Cj (10 )

2 where Pi was the milk treatment (raw or pasteurised), 3 12 i = 2, and Cj was the variety of cheese (Cantal or Saint- = 5 Nectaire), j 2 The date of milking was included as a 1 covariable in the model to take into account the stage 2 11 of grassland plant maturity. The value for the date 4 8+9 was between 5 and 29. Correlation coefficients for the 0 amounts of terpene desorbed with the date of cheese 30 35 40 45 50 55 6 making were calculated for groups of eight cheeses (b) min using Excel software and compared with the significant Figure 1. Profiles of the extracted ion chromatograms of m/z = 93 18 thresholds given by Snedecor and Cochran. for the retention times between 25 and 48 min (monoterpenes) and m/z = 161 from 48 to 65 min (sesquiterpenes). (a) Raw-milk Cantal cheese made on June 21 and (b) raw-milk Saint-Nectaire-type cheese made on June 26. 1: tricyclene, 2: -thujene, 3: -pinene, RESULTS α α 4: camphene, 5: β-pinene, 6: β-myrcene, 7: δ-3-carene, 8: limonene, Examples of extracted ion chromatograms are pre- 9: β-phellandrene, 10: (E)-β-ocimene, 11: γ -terpinene, sented in the Fig 1. A total of 51 terpenes were 12: β-caryophyllene.

2042 J Sci Food Agric 85:2040–2046 (2005) Terpene profiles in Cantal and Saint-Nectaire-type cheese

Table 1. Monoterpenoid compounds (arbitrary area unit × 10−5) desorbed from the cheese fat

Cantal cheese Saint-Nectaire cheese

Pasteurised Pasteurised Raw milk milk Raw milk milk

Cheese Milking Proposed Id type date identifications KIa qualb Medianc Var%d Median Var% Median Var% Median Var% effecte effecte

Santolinatriene 908 a 2.2 364 3.4 138 3.0 176 2.2 126 NS NS Tricyclene 928 a 9.4 109 11.1 176 0.0 0.0 ∗∗∗ NS α-Thujene 934 a 8.2 431 8.7 301 27.2 177 4.8 979 NS NS α-Pinene 944 a 151.1 72 165.7 75 55.2 172 55.7 109 ∗∗∗ NS Camphene 961 a 3.4 596 8.8 214 11.7 171 11.8 128 NS NS Sabinene 982 a 9.6 306 18.3 145 0.0 0.0 NS NS β-Pinene 989 a 34.3 303 33.6 82 42.6 155 43.9 70 NS NS β-Myrcene 992 a 21.6 151 26.1 149 3.2 209 6.1 136 ∗∗∗ NS Iso-m-menthane 1009 b 1.8 1111 0.9 260 1.3 148 1.0 45 NS NS α-Phellandrene 1013 a 12.9 175 8.6 141 0.0 0.0 ∗∗∗ NS δ-3-Carene 1021 a 26.5 308 33.7 97 3.8 172 5.9 122 ∗∗ NS α-Terpinene 1026 a 2.1 417 2.3 279 5.8 184 5.3 187 NS ∗∗ o-Cymene 1029 a 0.3 522 0.0 0.0 0.0 NS NS p-Cymene 1033 a 2.9 149 2.3 144 3.5 178 3.2 177 NS ∗∗ Limonene + β-Phellandrene 1038 a 79.8 157 98.2 116 12.4 136 20.1 94 ∗∗∗ NS (E)-β-Ocimene 1050 a 5.8 1007 0.0 0.3 220 8.5 141 NS NS γ -Terpinene 1067 a 15.8 334 10.9 406 16.4 267 18.2 235 NS ∗ Terpinolene 1098 a 9.3 413 9.6 322 10.6 131 8.0 68 NS NS 3-Thujanol 1177 a 0.9 252 0.0 0.0 0.0 NS NS Menthol 1186 a 0.3 213 0.0 0.8 152 0.4 218 NS NS γ -Terpineol 1205 a 1.2 252 1.6 141 0.0 0.0 ∗∗ NS Geraniol 1258 a 2.0 18 2.2 56 0.0 0.0 ∗∗∗ ∗∗ a KI: retention indices calculated according to Tranchant.13 b Id qual: quality of the identification: a, KI and mass spectra (MS); b, MS only. c Median values of the groups of four cheeses. d Variation amplitudes expressed as a percentage of the median value: 100 × (max − min)/median. e Effects of the variable ‘variety of cheese’ and the covariable ‘day of milking’: ∗∗∗ : p < 0.001, ∗∗ : p < 0.01, ∗ p < 0.05, NS : p > 0.05. The effect of milk treatment (not shown) was not significant in all cases.

The covariable ‘date’ was found significant at monoterpenes such as α-pinene and limonene, have p < 0.005 for α-terpinene, p-cymene and geraniol and long been found in milk volatile compounds4 and are at p < 0.05 for γ -terpinene, iso-caryophyllene, longi- considered common and ubiquitous. Many terpenes folene, γ -elemene, β-selinene and three unidentified however, are present in trace amounts in milk and sesquiterpenes at KI = 1342, 1426 and 1560. in cheese and need powerful analytical tools to be The terpene profiles varied greatly between cheeses detected. Terpene extraction from a ‘terpene rich’ milk of the same variety made on different days. In Cantal has been evaluated as approximately equivalent to that cheese, a significant correlation (p < 0.01) linking the observed in milk low in terpenes after adding 0.1 µlof day of milking (ie the date of cheese making) was essential oil per litre.19 Therefore, only recent papers observed for α-pinene (R = 0.98, Fig 2) and tricyclene report large diversities of terpene molecules.7,20 The (R = 0.81). In Saint-Nectaire cheese, β-myrcene (R = major terpenes found in the cheeses were previously 0.82), δ-3-carene (R = 0.82), p-cymene (R = 0.81) observed as major or abundant in the milk from and α-terpinene (R = 0.80) were correlated (p < 0.01) approximately the same herd grazing on the same with the day of milking. pasture.21 Twelve of the monoterpenes found, five of the sesquiterpenes and none of the oxygen-containing molecules were observed in milk produced from DISCUSSION pastures in the Alps.20 Milk from dairy cows grazed on diversified permanent Milk pasteurisation could have affected cheese ter- grasslands is known to contain a higher diversity pene profiles directly through the thermal treatment, and abundance of terpenoid compounds than can or indirectly via the suppression of the indigenous be obtained with any other type of diet.8 Agreat microflora. In fact, the relatively low temperature diversity of terpenes was found in both Cantal and applied (72 ◦C), the very short duration and the Saint-Nectaire cheeses, regardless of whether the milk absence of air oxygen, did not constitute a dras- had been pasteurised or not. The most abundant tic treatment, considering that terpenes, as the main

J Sci Food Agric 85:2040–2046 (2005) 2043 ACornuet al

Table 2. Sesquiterpenoid compounds desorbed (arbitrary area unit × 10−5) from the cheese fat

Cantal cheese Saint-Nectaire cheese

Pasteurised Pasteurised Raw milk milk Raw milk milk

Cheese Milking Id type date KIa qualb Medianc Var%d Median Var% Median Var% Median Var% effecte effecte

African-2(6)-ene 1328 b 0.2 3119 0.2 2226 0.7 169 2.2 152 NS NS S 1342 — 0.0 0.0 3.8 141 5.8 29 ∗∗∗ ∗ α-Cubebene 1385 a 0.0 0.0 0.9 156 1.4 64 ∗∗∗ NS Ester 1386 — 0.4 266 0.0 0.0 0.0 ∗ NS α-Copaene 1405 a 14.2 396 13.9 310 20.8 123 25.7 53 NS NS Oxygen-containing S 1412 — 0.4 288 0.3 242 0.0 0.0 ∗ NS β-Bourbonene 1418 a 1.2 1635 2.7 560 4.9 185 9.7 24 NS NS S 1426 — 0.0 0 0.0 0.4 553 0.5 458 NS ∗ Iso-caryophyllene 1442 a 1.5 253 1.7 109 3.8 143 3.5 75 NS ∗ Longifolene 1444 a 0.0 0.0 2.1 102 2.2 26 ∗∗∗ NS α-Gurjunene 1445 a 2.1 205 1.7 251 1.5 123 1.6 85 NS NS Aromadendrene 1451 a 0.0 2.4 160 0.0 0.0 NS NS β-Gurjunene 1452 a 2.9 223 0.6 674 0.0 0.0 ∗∗ NS β-Caryophyllene 1454 a 25.9 487 32.7 271 94.3 142 97.3 75 NS ∗ β-Ylangene 1459 a 0.0 0.0 2.2 135 1.9 128 NS NS β-Cedrene 1464 a 3.1 383 3.1 278 0.0 0.0 ∗ NS γ -Elemene 1473 a 0.6 341 0.0 6.8 99 7.1 45 ∗∗∗ ∗ γ -Muurolene 1486 a 0.0 0.0 1.6 227 1.3 186 NS NS α-Humulene 1492 a 8.5 537 14.4 228 24.7 112 24.8 115 NS NS γ -Gurjunene 1507 a 0.0 0.0 4.8 88 5.6 38 NS NS trans-Muurola-4(14),5-diene 1508 a 1.2 275 1.7 705 0.0 0.0 NS NS S 1511 — 0.0 0.0 7.4 169 7.2 12 ∗∗∗ NS Valencene 1518 a 0.0 9.8 181 0.0 0.0 ∗ NS γ -Himalachene 1522 a 5.8 393 5.8 311 6.3 201 10.5 53 NS NS β-Selinene 1527 a 0.0 0.0 1.0 756 7.1 104 NS ∗ γ -Cadinene 1548 a 1.4 754 1.4 723 0.0 0.0 NS NS δ-Cadinene 1551 a 4.7 294 5.9 154 12.4 116 11.0 152 NS NS S 1560 — 0.0 0.0 2.1 125 2.1 147 ∗∗ ∗ a–e See Table 1 for footnotes. S: unidentified sesquiterpene.

(aau) an important role in Swiss-type cheese aroma during α-pinene R 2 = 0.96∗∗ maturation.22 Buchin et al23 found volatile compound 2e7 differences between raw and pasteurised milk in semi- hard cheese. The first one contained higher amounts of alcohols, fatty acids and sulphur compounds, the 1.5e7 second one higher amounts of ketones, but none of the seven terpenes detected was affected by milk pas- 7 1e teurisation. Terpene profile differences between Cantal and 5e6 R 2 = 0.54∗ Saint-Nectaire cheese varieties were significant. These differences may have originated from a combination of physical, chemical, biochemical or microbial 5101520 25 Day (June) mechanisms during the cheese making. For example, Figure 2. α-Pinene desorbed from the cheese fat (arbitrary area unit). in both cheese making procedures, the milk had been Cantal cheese: full symbols, Saint-Nectaire cheese: empty symbols. initially heated to 33 ◦C. This might have induced Raw milk cheeses: losanges, pasteurised milk cheeses: triangles. some terpenes to evaporate, at rates that depended Dotted lines: adjusted curves among groups of eight (Cantal or Saint-Nectaire) cheeses. R2: correlation coefficients with the milking on the volume of milk being heated, the method of date (days) and their significance (∗∗: p < 0.01, ∗: p < 0.05). stirring, the porosity of the curd, etc. In addition to the variation in cheese making technology, the microbial flora may have induced different chemical reactions constituents of essential oils, resist hydrodistillation. on terpene molecules. The many differences between Milk indigenous microflora has been shown to play the two cheese making processes may be important

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Association pasteurisation. de Coordination Technique Agricole (ACTA), Paris, 649 pp (1957). 19 Martin B, Verdier-Metz I, Cornu A, Pradel P, Hulin S, Buchin S, Dupont D, Lamaison JL, Carnat A-P, BerdagueJLand´ Coulon JB, Do terpene influence the flavour of cheeses? Ii. ACKNOWLEDGEMENT Cantal cheese. Caseus Int 2:25–27 (2003). This work was supported by an AQS program of the 20 Buchin S, Salmon JC, Carnat A-P, Berger T, Bugaud C and Bosset JO, Identification de composes´ monoterpeniques,´ French Government. The authors wish to thank the sesquiterpeniques´ et benzeniques´ dans un lait d’alpage INRA staffs of Marcenat and of Aurillac and Julie particulierement` riche en ces substances. Mitt Lebensm Hyg Michels, student. 93:199–216 (2002).

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21 Cornu A, Kondjoyan N, Carnat A-P, Martin B and 23 Buchin S, Delague V, Duboz G, Berdague´ JL, Beuvier E, Berdague´ JL, Nature des composes´ terpeniques´ de laits de Pochet S and Grappin R, Influence of pasteurization and vaches alimentees´ avec differents´ regimes.´ 10emes` Rencontres fat composition of milk on the volatile compounds and Recherches Ruminants (2003). flavor characteristics of a semi-hard cheese. JDairySci 22BeuvierE,BerthaudK,CegarraS,DasenA,PochetS,Buchin 81:3097–3108 (1998). S and Duboz G, Ripening and quality of Swiss-type cheese 24 Larsen TO, Identification of cheese-associated fungi using made from raw, pasteurized or microfiltered milk. Int Dairy J selected ion monitoring of volatile terpene. Lett Appl Microbiol 7:311–323 (1997). 24:463–466 (1997).

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