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The development of analytical methods to verify the production system of meat products requires the identification of biomarkers that can trace the product’s origin, and secondly the factors that govern the deposition of these markers in animal tissue need to be defined. In this study, 2,3-octanedione, skatole and terpenes were selected as biomarkers, and their deposition was investigated in bull calves reared under three different strategies. All of the animals were reared indoors until approximately 150 days of age. They were suckled twice a day by their mothers, and both calves and cows had free access to cocksfoot hay. Then the first two groups of animals were kept indoors, suckled by their mothers twice a day and received either cocksfoot hay (HL) or freshly cut-green herbage (GL) and a limited quantity of concentrate. The third group of calves (PH) was kept on pasture with their mothers and offered concentrate ad libitum. The pasture supporting the PH animals was highly diversified, containing several terpene-rich plant species, whereas the herbage for the GL animals contained no species known to be aromatic. Perirenal and subcutaneous adipose tissues were analysed for volatile compounds. The perirenal fat was found to be more responsive to the treatment and a more reliable substrate than the subcutaneous adipose tissue. Higher levels of 2,3-octanedione (P < 0.05) were found in PH and GL than in HL fat (6.56, 6.51 and 5.77 area arbitrary units, respectively, in perirenal fat), confirming the ability of this molecule to trace green herbage feeding. Skatole was detected in the perirenal and subcutaneous fat of all the animals. Animals receiving high concentrate level (PH group) presented lower (P < 0.05) skatole values (5.83 area arbitrary units in perirenal fat) than animals receiving low concentrate level (HL and GL groups, 6.23 and 6.71 area arbitrary units, respectively, in perirenal fat). Terpenoids, and especially sesquiterpenes, were found at higher levels and diversities in the PH than in the GL and HL animals. Two monoterpenoids allowed group discrimination considering perirenal or subcutaneous fat without distinction, whereas 11 and 5 sesquiterpenoids from perirenal and subcutaneous fat, respectively, allowed it.

The last decade has seen important developments in the use of carotenoid pigments to authenticate pasture-feeding in ruminants. However, dehydrated alfalfa is sometimes incorporated in grain-based concentrates fed to stall-raised lambs, which may affect the reliability of the pasture-feeding authentication methods based on carotenoids in plasma and fat, due to significant residual carotenoid levels post-dehydration. The aim of this study was to examine whether other compounds can give additional information to authenticate diet and discriminate pasture-fed lambs from lambs fed high levels of alfalfa indoors. Two feeding treatments were compared: pasture-feeding (P) v. stall-feeding with dehydrated alfalfa (A). Each treatment group consisted of seven male Romanov × Berrichon lambs. Pasture-fed (P) lambs grazed a permanent graminaceae-rich pasture maintained at a leafy, green stage, offered ad libitum; they received no supplementation at pasture. A-group lambs were individually penned and fed dehydrated alfalfa and straw; their feed level was adjusted to achieve a similar growth pattern as for P-group lambs. Plasma carotenoid concentration was measured at slaughter by spectrophotometry. The reflectance spectrum of perirenal and subcutaneous caudal fat was measured at 24-h post mortem and used to calculate an index (absolute value of the mean integral (AVMI)) quantifying light absorption by carotenoid pigments present in the fat. The nitrogen (N) stable isotopes ratio (δ15N) in both feed and longissimus dorsi muscle was measured by isotopes ratio mass spectrometry (IRMS). Volatile compounds were analyzed in perirenal fat for five randomly chosen lambs per treatment, using dynamic headspace–gas chromatography–mass spectrometry. Plasma carotenoid concentration and AVMI of the fat did not differ significantly between P- and A-group lambs, but there were significant between-treatment differences in meat δ15N values and in the terpene profiles of perirenal fat. A discriminant analysis performed using three compounds in different animal tissues (δ-cadinene in perirenal fat, δ15N value of the meat and plasma carotenoid concentration) clearly separated pasture-fed lambs from lambs fed high levels of alfalfa indoors.

Several efforts have been done in the last years to trace grass feeding directly in the herbivore products and different methods, based on carotenoid pigments (Priolo et al., 2002; Prache et al., 2003) have been proposed. Some volatile compounds, such as 2,3-octanedione or 3-methylindole (skatole) have been indicated as excellent indicators of pasture diets (Young et al., 1997)...

While autoxidation of Polyunsaturated Fatty Acids (PUFAs) is a potential source of furan and its derivatives, the regulatory obligation to enrich powdered infant formulae (PIF) with some of these compounds might raise safety issues. The aim of this study was to investigate the impact of formulation and home storage conditions on the generation of furan and its derivatives in PIF. Furan, 2-methylfuran (2-MF) and 3-methylfuran (3-MF) were monitored by a validated SHS-GC-Q Exactive-Orbitrap MS method in six PIF formulated with high or low concentrations of different PUFAs (ALA, ARA, DHA), pro-oxidants (iron) and anti-oxidants (vitamins) and stored for 21 days under more or less oxidizing home storage conditions, including temperature (19 °C or 40 °C) and oxygen exposure (protected or not from ambient air). For the three compounds, the quality of the measurements in PIF was first confirmed with suitable linearity, limits of quantification, precision and recoveries. In a second step, the impact of the formulation was evaluated on six PIF commercial samples differing significantly in their composition in ALA, ARA, DHA, iron and/or vitamin E and C. While furan was quantifiable (2.8 µg/kg) in only one PIF with high content of DHA and iron and low level of vitamins, 2-MF was only quantifiable in two other PIF which were distinguished by a 15 to 20 % higher ALA content and 3-MF was not detected in any of the six PIF studied. In a third step, the effect of storage conditions was studied on the six PIF and the increase in storage temperature to 40 °C led to an increase of up to 33 % in the 2-MF concentration in the two PIF formulations where it was quantifiable. Nevertheless, the estimation of the Margin of Exposure (MOE) showed that the risk related to furan and its derivatives could be ruled out regardless of the formulation or storage conditions. Finally, in order to explore other derivatives and to investigate the mechanisms involved in the generation of furan compounds in PIF, a suspect screening approach was implemented on the SHS-GC-Q Exactive-Orbitrap MS data. It made it possible on the one hand to point out two additional furan derivatives in PIF, 2-ethylfuran and 2-pentylfuran. On the other hand, it enabled to discuss the oxidation pathways involved in the generation of furan compounds in PIF from profiling of known PUFA oxidation markers also detected in the samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

This study assessed the impact of current home practices including reheating, standing, and stirring on mitigation of furan and its derivatives in vegetable-based infant meals. Three vegetable-based infant meals (vegetables alone, with fish, with meat) underwent different home practices including reheating, post-reheating standing (60, 120 and 240 s) and post-reheating stirring (30, 60, 120 and 240 s). Targeted quantification of furan, 2-methylfuran (2-MF) and 3-methylfuran (3-MF) and exploration of additional furan derivatives were undertaken in treated and untreated vegetable-based infant meals using SHS-GC-Q Exactive-Orbitrap-MS. For the three compounds, the quality of the measurements was first validated with suitable linearity, limits of quantification, precision and recoveries. A second step highlighted high concentrations of furan (78.5-103.9 µg/kg), 2-MF (4.8-10.1 µg/kg) and 3-MF (3.4-5.8 µg/kg) in the three vegetable-based infant meals before preparation and the assessment of the cumulative risk related to these three furan compounds confirmed the relevance of studying home mitigation strategies. The third step showed that post-reheating stirring was the most effective home practice for mitigation, with maximum observed reductions of 66.3, 59.9 and 57.7 % for furan, 2-MF and 3-MF, respectively. In a fourth step, a suspect screening approach carried out on SHS-GC-Q Exactive-Orbitrap MS data revealed the presence of 2-ethyl-, 2-ethyl-5-methyl-, 2-butyl- and 2-vinyl-furan in vegetable-based meals and showed a similar mitigation trend of home practices on the relative concentrations of these four additional furan derivatives. Finally, despite a significant mitigation reaching 69 % of the furan concentration, the combined effect of home practices on furan compounds was not sufficient to rule out the risk associated with the consumption of vegetable-based infant foods and additional options are discussed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The aim of the present study was to assess the performance and complementarity of methods capable of both quantifying furan, 2-Methylfuran (2-MF) and 3-Methylfuran (3-MF) in infant foods, but also to comprehensively explore other furan derivatives. It is more particularly a question of validating and comparing the couplings of the two headspace extraction methods most used for the analysis of furan compounds - Headspace Solid Phase Microextraction (HS-SPME) and Static HeadSpace (SHS) - with gas chromatography hyphenated to a high-resolution mass detector (Q Exactive-Orbitrap MS) which allows both targeted quantification and suspect screening. Firstly, the accuracy profile approach was implemented to assess, validate and compare HS-SPME- and SHS-GC-Q Exactive-Orbitrap MS for the quantification of furan in two model infant foods, apple puree and first infant formula. SHS-GC-Q Exactive-Orbitrap MS, showed better accuracy (uncertainty < 17.2 % vs 22.5 % for HS-SPME GC-Q Exactive-Orbitrap MS) and better sensitivity (LOQ < 2.8 vs LOQ < 4.0 µg/kg) over a broader validation range (2-100 µg/kg vs 5-100 µg/kg in apple puree). Secondly, SHS-GC-Q Exactive-Orbitrap MS was assessed and validated by accuracy profile for the quantification of 2-MF and 3-MF, with performance close to those for furan except for 3-MF in apple puree. Thirdly, SHS-GC-Q Exactive-Orbitrap MS was used to quantify the levels of these compounds in 20 commercial samples (n = 3) belonging to the four main categories of infant food (infant formulae, fruit purees, infant cereals, vegetable/fish baby meals). Furan was quantified in 75 % of the samples, with maximum levels in the vegetable/fish-based infant foods (up to 127 µg/kg) while 2-MF and 3-MF were quantified in 45 % and 15 % of products respectively, with maximum levels of 14.1 µg/kg in follow-on formula 3 rd age and 9.2 µg/kg in apple puree. Finally, SHS- and HS-SPME-GC-Q Exactive-Orbitrap MS data of the 20 infant products were processed in suspect screening mode using Compound Discoverer TM software. Coupling with HS-SPME, it made it possible to identify 13 additional furan derivatives, i.e. 5 more than with SHS. The relevance and safety status of the compounds identified are discussed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

In a previous work, we studied the inhibition of heterocyclic aromatic amine formation by natural ingredients rich in antioxidants: caper, oregano, wine and green tea. This present work aimed to assess the sensory impact of the addition of these ingredients in ground beef patties. The best liked formulations were determined by a hedonic scoring. Caper and oregano were not significantly different from the standard, the most appreciated, due to their congruency with cooked meat. Direct dissimilarity assessment was performed to evaluate the overall, gustative and odor differences between formulations. Olfactive differences were evidenced as key drivers of these differences. Standard and caper were close while oregano was found significantly different from them. A fast sensory profiling permitted to evidence that aromatic plant note was discriminant for oregano formulation. Gas chromatography-mass spectrometry/multibooth olfactometry identified the distinctive odor-active compounds of the formulations as pyrazines and sulfide for oregano formulation and ester for caper formulation., Competing Interests: Declaration of Competing Interest The authors declare that there is no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Volatile organic compounds (VOC)-based metabolomics, or volatolomics, was investigated for revealing livestock exposure to chemical contamination. Three farm animals, namely laying hens, broilers, and pigs, were experimentally exposed to 5 or 50 ng α-HBCDD g -1 feed. Liver and egg yolk for hens were analysed by headspace-SPME-GC-MS to reveal candidate markers of the livestock exposure to α-HBCDD. For hens, 2-butanol was found as marker in egg. In liver, twelve VOCs were highlighted as markers, with three aromatic VOCs - styrene, o-xylene, α-methylstyrene - highlighted for the two α-HBCDD doses. For broilers, six markers were revealed, with interestingly, styrene and phenol which were also found as markers in hen liver. For pigs, ten markers were revealed and the seven tentatively identified markers were oxygenated and sulfur VOCs. The candidate markers tentatively identified were discussed in light of previous volatolomics data, in particular from a γ-HBCDD exposure of laying hens., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

GYNOPHILUS (Lcr REGENERANS) is a live biotherapeutic product (LBP) aimed at restoring the vaginal microbiome and contains the live biotherapeutic microorganism Lactobacillus rhamnosus Lcr35. In this study, the LBP formulation and manufacturing process significantly enhanced the anti-Candida activity of L. rhamnosus Lcr35, with a complete loss of viability of the yeast after 48 h of coincubation. Sodium thiosulfate (STS), one excipient of the product, was used as a potentiator of the anti-Candida spp. activity of Lactobacilli. This contact-independent phenomenon induced fungal cell disturbances, as observed by electron microscopy observations. Nonverbal sensory experiments showed clear odor dissimilarities between cocultures of L. rhamnosus Lcr35 and C. albicans in the presence and absence of STS, suggesting an impact of odor-active metabolites. A volatolomic approach allowed the identification of six odor-active compounds, including one sulfur compound that was identified as S-methyl thioacetate (MTA). MTA was associated with the antifungal effect of Lcr35, and its functional link was established in vitro. We show for the first time that the LBP GYNOPHILUS, which is a highly active product in the reduction of vulvovaginal candidiasis, requires the presence of a sulfur compound to fully achieve its antifungal effect.

Hexabromocyclododecane (HBCD) is a critical emerging brominated flame retardant to which consumers can be exposed at high doses through a single food intake. Based on an animal experiment involving 3 groups of laying hens fed during 70 days with a control diet or γ-HBCD-contaminated diets at 0.1 or 10 μg γ-HBCD g -1 feed, this study aims to use the volatolome of biological samples for revealing markers of livestock exposure to HBCD. Liquid chromatography-tandem mass spectrometry was used to monitor the time-course of HBCD levels in bodily samples. Each liver was analyzed by solid-phase microextraction-gas chromatography-mass spectrometry for volatolome profiling. After 70 days, γ-HBCD concentrations in egg yolk, fat, liver and serum reached 54 ± 4, 85 ± 6, 31 ± 6, and 32 ± 4 ng g -1 lw, respectively, for the low exposure level and 4.6+/5.7, 7.8+/6.5, 3.9+/3.0 and 3.9+/6.1 μg g -1 lw, respectively, for the high exposure level. Isomerization of γ-HBCD into α- and β-HBCD was observed in all tissues, at least for the high exposure level. Volatolome data allowed a significant discrimination between control and exposed animals whatever the feed contamination load, demonstrating a liver metabolic response to γ-HBCD exposure. The relevance of the twenty nine volatile exposure markers tentatively identified was discussed in light of literature data., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Starting with an experiment to authenticate walnut oils based on GC-MS analysis of the volatolome, this paper aims to demonstrate the relevance of a two-step alignment-based strategy for the systematic research of VOC markers. The first step of the treatment consists of roughly reducing the time shifts with efficient, known warping techniques like COW (Correlation Optimized Warping). The second step relies on an accurate peak apex alignment in order to refine residual local misalignments and to enable further systematic marker research through univariate or multivariate data treatments. This two-step strategy was implemented on 117 GC-MS analyses of the volatolome of three vegetable oils with very similar composition. During the analysis campaign, the GC-MS system was intentionally subjected to instrumental drifts in order to generate realistic signal shifts. The first part of this study aims to assess the efficiency of the warping-based strategy in terms of signal alignment and sample discrimination. Whereas no distinction between the three oils was possible with unaligned raw GC-MS data, the application of COW enabled a significant but insufficient improvement of both reduction of temporal drifts and between-group separation with 79% of samples being well-classified according to Linear Discriminant Analysis (LDA). Applying the peak apex alignment procedure to COW-treated signals resulted in a suitable correction of the remaining local distortions and improved the proportion of well-classified samples in LDA to 100%. The second part of this study assesses the robustness of the discriminant markers highlighted in this approach by: (i) discussing the relevance of the best markers involved in the LDA model, where a close review of literature confirmed the consistency for two of them, and (ii) validating highlighted makers by retrieving the set of the 23 markers previously determined by manual processing among those automatically found. The third part shows the potential of the systematic approach for untargeted detection of 184 highly significant relevant markers from the oil volatolome. Finally, the fourth part presents a comparison of our hybrid alignment strategy with two reference alignment methods (iCoshift and STW) in order to assess quality alignment of the GC-MS data and to show the three methods' abilities to detect discriminant markers., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The assessment of the dual impact of heating treatments on food safety and aroma is a major issue for the food sector. The aim of the present study was to demonstrate the relevance of multidimensional GC techniques, olfactometry and mass spectrometry for the parallel determination of process-induced toxicants and odorants in food starting with cooked meat as a food model. PAHs were analyzed by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry after extraction by accelerated solvent extraction (ASE-GC × GC-TOF/MS). Odour-active compounds were determined by dynamic headspace-GC hyphenated with eight booth olfactometry and mass spectrometry (DH-GC-MS/8O) and DH-heart-cutting multidimensional GC hyphenated with olfactometry and mass spectrometry (DH-GC-GC-MS/O). For PAH determination, the GC × GC conditions consisted of a combination of a primary non-polar BPX-5 column and a secondary polar BPX-50 column, and a modulation period of 5s. In terms of linearity (R(2) ranging from 0.985 to 0.997), recovery rate (84-111%) and limit of detection (5-65 ng/kg of cooked meat), the ASE-GC × GC-TOF/MS method was found consistent with the multiresidue determination of 16 PAHs including benzo[a]pyrene in cooked meat. For aroma compounds, DH-GC-MS/8O and DH-GC-MS/O revealed 53 major meat odour-active compounds. A customized heart-cutting GC-GC-MS/O enabled the coeluting odour zones with high odour-activity to be resolved and revealed 15 additional odour-active compounds. Finally, these developments of multidimensional approaches were used to investigate the balance between 16 PAHs and 68 odour-active compounds generated with different cooking techniques., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The development of analytical methods to verify the production system of meat products requires the identification of biomarkers that can trace the product's origin, and secondly the factors that govern the deposition of these markers in animal tissue need to be defined. In this study, 2,3-octanedione, skatole and terpenes were selected as biomarkers, and their deposition was investigated in bull calves reared under three different strategies. All of the animals were reared indoors until approximately 150 days of age. They were suckled twice a day by their mothers, and both calves and cows had free access to cocksfoot hay. Then the first two groups of animals were kept indoors, suckled by their mothers twice a day and received either cocksfoot hay (HL) or freshly cut-green herbage (GL) and a limited quantity of concentrate. The third group of calves (PH) was kept on pasture with their mothers and offered concentrate ad libitum. The pasture supporting the PH animals was highly diversified, containing several terpene-rich plant species, whereas the herbage for the GL animals contained no species known to be aromatic. Perirenal and subcutaneous adipose tissues were analysed for volatile compounds. The perirenal fat was found to be more responsive to the treatment and a more reliable substrate than the subcutaneous adipose tissue. Higher levels of 2,3-octanedione (P < 0.05) were found in PH and GL than in HL fat (6.56, 6.51 and 5.77 area arbitrary units, respectively, in perirenal fat), confirming the ability of this molecule to trace green herbage feeding. Skatole was detected in the perirenal and subcutaneous fat of all the animals. Animals receiving high concentrate level (PH group) presented lower (P < 0.05) skatole values (5.83 area arbitrary units in perirenal fat) than animals receiving low concentrate level (HL and GL groups, 6.23 and 6.71 area arbitrary units, respectively, in perirenal fat). Terpenoids, and especially sesquiterpenes, were found at higher levels and diversities in the PH than in the GL and HL animals. Two monoterpenoids allowed group discrimination considering perirenal or subcutaneous fat without distinction, whereas 11 and 5 sesquiterpenoids from perirenal and subcutaneous fat, respectively, allowed it.

The aim of this work was to reliably identify odour-active compounds in dry-cured ham using powerful analysis methods for the volatile fraction. For this purpose, dynamic headspace gas chromatography combined with eight-way olfactometry using a panel of eight sniffers was used. One- and two-dimensional gas chromatography coupled with mass spectrometry and (or) olfactometry were also used. More than 600 compounds from the volatile fraction of dry-cured ham were identified and their biochemical origins are discussed. They covered a wide diversity of structures and chemical functions. Only 29 of them proved odour-active. Comparison of the results of GC-O analysis with those obtained by orthonasal sniffing of the dry-cured ham helped to gain a better understanding of how these substances contributed to the overall aroma of the product. Thus, "Fruity-Floral", "Green-Vegetable" or "Plastic-Chemical" odours intensively perceived by GC-O have been poorly perceived by orthonasal sniffing. By contrast, "Animal-Meat products" or "Butter-Lactic-Cheesy" odours have been much better perceived by orthonasal sniffing. These results indicate that to understand the interactions between odour-active compounds, experimental doping with carefully selected odour-active compounds will be necessary., (Copyright 2010 Elsevier Ltd. All rights reserved.)

The last decade has seen important developments in the use of carotenoid pigments to authenticate pasture-feeding in ruminants. However, dehydrated alfalfa is sometimes incorporated in grain-based concentrates fed to stall-raised lambs, which may affect the reliability of the pasture-feeding authentication methods based on carotenoids in plasma and fat, due to significant residual carotenoid levels post-dehydration. The aim of this study was to examine whether other compounds can give additional information to authenticate diet and discriminate pasture-fed lambs from lambs fed high levels of alfalfa indoors. Two feeding treatments were compared: pasture-feeding (P) v. stall-feeding with dehydrated alfalfa (A). Each treatment group consisted of seven male Romanov × Berrichon lambs. Pasture-fed (P) lambs grazed a permanent graminaceae-rich pasture maintained at a leafy, green stage, offered ad libitum; they received no supplementation at pasture. A-group lambs were individually penned and fed dehydrated alfalfa and straw; their feed level was adjusted to achieve a similar growth pattern as for P-group lambs. Plasma carotenoid concentration was measured at slaughter by spectrophotometry. The reflectance spectrum of perirenal and subcutaneous caudal fat was measured at 24-h post mortem and used to calculate an index (absolute value of the mean integral (AVMI)) quantifying light absorption by carotenoid pigments present in the fat. The nitrogen (N) stable isotopes ratio (δ15N) in both feed and longissimus dorsi muscle was measured by isotopes ratio mass spectrometry (IRMS). Volatile compounds were analyzed in perirenal fat for five randomly chosen lambs per treatment, using dynamic headspace-gas chromatography-mass spectrometry. Plasma carotenoid concentration and AVMI of the fat did not differ significantly between P- and A-group lambs, but there were significant between-treatment differences in meat δ15N values and in the terpene profiles of perirenal fat. A discriminant analysis performed using three compounds in different animal tissues (δ-cadinene in perirenal fat, δ15N value of the meat and plasma carotenoid concentration) clearly separated pasture-fed lambs from lambs fed high levels of alfalfa indoors.

The aim of this experiment was to study the effect of the addition, to milk, of an essential oil (EO) obtained from the hydrodistillation of plants collected from a mountain natural pasture on the milk and cheese sensory properties. The EO was mainly composed of terpenoid compounds (67 of the 95 compounds identified) as well as ketones, aldehydes, alcohols, esters, alkanes, and benzenic compounds. In milk, the addition of this EO at the concentration of 0.1 microL/L did not influence its sensory properties, whereas at 1.0 microL/L, sensory properties were modified. In cheeses, the effect of adding EO into milk was studied in an experimental dairy plant allowing the production of small Cantal-type cheeses (10 kg) in 3 vats processed in parallel. The control (C) vat contained 110 L of raw milk; in the other 2 vats, 0.1 microL/L (EO1) or 3.0 microL/L (EO30) of EO were added to 110 L of the same milk. Six replicates were performed. After 5 mo of ripening, chemical and sensory analyses were carried out on the cheeses, including determination of the volatile compounds by dynamic headspace combined with gas chromatography-mass spectrometry. The EO did not influence the sensory properties of the cheeses at the lower concentration (EO1). However, the EO30 cheeses had a more intense odor and aroma, both characterized as "mint/chlorophyll" and "thyme/oregano." These unusual odors and aromas originated directly from the EO added. In total, 152 compounds desorbing from cheese were found, of which 41 had been added with the EO; in contrast, 54 compounds of the EO were not recovered in the cheese. Few volatile compounds desorbing from cheeses, other than the added compounds, were affected by EO addition. Among them, 2-butanol, propanol, and 3-heptanone suggested a slight effect of the EO on lipid catabolism. The antimicrobial activity of terpenes is not or is only marginally involved in the explanation of the influence of the botanical composition of the meadows on the pressed cheeses sensory properties.

Changes of terpene content in milk from cows grazing natural diversified upland pasture were examined in this observational trial. A homogeneous plot divided into 2 subplots was used from May 31 to July 1, 2003 (first growth) and again from October 1 to October 7, 2003 (vegetative regrowth). Each subplot was grazed by 6 dairy cows in 2 ways: strip grazing (SG), with new allocations of pasture strips at 2-d intervals, and paddock grazing (PG). The PG subplot was divided into 3 paddocks and the cows were moved to a new paddock on June 13 and June 24, 2003. Milk from the 6 cows was collected twice a week, pooled, and used for terpene analyses by dynamic headspace gas chromatography-mass spectrometry system. Twenty mono- and 23 sesquiterpenes desorbing from the milk fat were separated. The most abundant monoterpenes were beta-pinene, alpha-pinene, gamma-terpinene, limonene, alpha-tujene, terpinolene, and alpha-phellandrene. The most abundant sesquiterpenes were beta-caryophyllene, alpha-copaene, beta-cedrene, transmuurola-4-(14)-5-diene, beta-bisabolene, and delta-cadinene. Both mono- and sesquiterpenes in SG milk increased across time with an 8-fold increase in total terpenes in milk from the beginning to the end of June. In parallel, dicotyledons, including the main terpene-rich plants, increased from 17 to 31% of total biomass of the vegetation and the development of Dactylis glomerata progressed from boot to ripening stage. The terpenes in PG milk were equivalent to those in SG milk for the first paddock at the beginning of June and remained constant or doubled for the sum of mono- and sesquiterpenes, respectively. The lower variability of the PG milk terpene content could be related to the opportunity that PG cows had to choose ingested herbage, whereas the SG cows had limited choice within the smaller allocated pasture strips. Milk from cows grazing regrowth pastures in October contained low levels of terpenes, and values were similar for PG and SG milks. Change in the sum of monoterpenes is representative of changes for most monoterpenes (except for limonene) and, conversely, the change in the sum of sesquiterpenes mainly reflected changes in beta-caryophyllene and alpha-copaene. In addition to effects of botanical composition of pasture, it appears that terpene content in milk may vary according to factors linked to grazing management that need more intensive study. Nevertheless, current results raise questions about the precision of terpenes as feed tracers.

Volatile compounds were analysed in subcutaneous fat from lambs raised and finished on grass (GG); raised and finished on concentrates (SS); raised on grass and finished on concentrates for a long (GS1) or a short (GS2) period. Whereas 3-methylindole (skatole), a compound that has been described as a good discriminator of grass feeding, was unaffected by the diet (P>0.05), 2,3-octanedione was lower (P<0.01) in the fat from animals that spent a period in stall with a concentrate diet than in those finished on grass. Among the 20 monoterpenes detected, only p-cymene was affected by the treatment, being higher (P<0.05) in the fat from animals raised and finished on grass (GG) than in the other treatments. Eight among the 13 detected sesquiterpenes were affected by the diet treatment. In particular β-caryophyllene, not detected in the fat from animals raised and finished on concentrates (SS group), was at basal levels in the animals raised on pasture and finished for different durations on concentrates (GS1 and GS2 treatments) and was present at high levels in the animals raised and finished on grass (P<0.0005). From a factorial discriminant analysis, four of the 33 terpenes detected discriminated perfectly those animals raised and finished on pasture (GG) from all the other groups (SS, GS1, GS2).