Vincent Varlet - Academia.edu (original) (raw)

Papers by Vincent Varlet

Food Science and Technology International, 2010

An inventory of the most part of sulfur-containing volatile compounds (SCVCs) present in seafood ... more An inventory of the most part of sulfur-containing volatile compounds (SCVCs) present in seafood was carried out. These molecules constitute key compounds to understand and improve seafood quality. According to their nature, concentration and environmental parameters (temperature), they can move the overall seafood odor from desirable to rotten. Sulfury odors can also indicate problems in sanitary quality. Thus, it is essential to monitor the generation of these compounds to better control the organoleptic and sanitary quality of seafood. SCVC were divided in two categories: aliphatic compounds and cyclic compounds. Among cyclic SCVC, several families of compounds can be distinguished as thiophenes, thiazoles and their respective derivatives. The main pathways of formation of SCVC in seafood are investigated in order to better understand their presence in seafood aroma. Microbial mediated enzymatic reactions are mainly implied in the generation of aliphatic SCVC whereas Maillard reactions are involved in the generation of cyclic SCVC. A small part of SCVC could also derive from the environment by direct bioaccumulation of S-containing molecules or precursors. Then, the occurrence of SCVC in seafood is discussed according to the extraction methods, analysis methods sometimes olfactometric methods and the species the state and the average biochemical composition of the seafood matrix in which they were recovered. Finally, among the identified SCVC, the odorant properties of odor-active volatile compounds were investigated. Aromatic notes and odorant thresholds for odorant SCVC of seafood aroma are listed. Both pathways of formation and lists of SCVC linked to their odorant properties constitute important indicators to optimise seafood quality from an organoleptic and sanitary point of view.

Food Chemistry, 2007

The representativeness of an aromatic extract of smoked salmon obtained from simultaneous steam d... more The representativeness of an aromatic extract of smoked salmon obtained from simultaneous steam distillation and extraction with diethyl ether is discussed. After extraction, the extract is diluted in ethanol with an evaporation of diethyl ether, which allows the extract to be redeposited on matrices physically similar to those of the original product. When the shift of the matrix effect is

Journal of The Science of Food and Agriculture, 2007

Four industrial processes for smoking food were studied through their effects on the organoleptic... more Four industrial processes for smoking food were studied through their effects on the organoleptic properties of smoked salmon and on the occurrence of 20 polycyclic aromatic hydrocarbons (PAHs) known as being contaminants of smoking processes. The contamination by PAHs of the food might be measured by their corresponding toxic equivalent quantity (TEQ) expressed in µg kg−1. The results show a significant correlation between the smoking process parameters, the odour of the smoked fish and the presence of PAHs. Smouldering, thermostated plates and friction smoking processes allow smoked fish with very close odorant characteristics to be obtained. However, differences of pyrolysis temperature (between 380 and 500 °C) causes significant differences of PAHs concentration even if the contents are under the legal threshold concerning benzo(a)pyrene (5 µg kg−1). Smoked fish obtained by liquid smoke vaporisation presented the lowest level of PAHs but benzo(a)pyrene concentration is nevertheless important. The odours brought by the liquid smoke process are more ‘cold smoke’ and ‘vegetal/green’ than the other techniques, which are smokier and fishier. Copyright © 2007 Society of Chemical Industry

Journal of Chromatography A, 2007

An efficient and selective analytical method for the determination and the quantification of 19 p... more An efficient and selective analytical method for the determination and the quantification of 19 polycyclic aromatic hydrocarbons (PAHs) in food and oil has been developed. This method includes the monitoring of 15 PAHs stated as a priority by the EU in their 2005/108 recommendation. The samples were extracted according to a selective extraction step using pressurized liquid extraction followed by a purification with polystyrenedivinylbenzene SPE. Identification and quantification were performed using GC-MS/MS, with an isotope dilution approach using 13 C-labelled PAHs. The novel combination of selective extraction followed by purification provides highly purified analytes combined to a fast and automated method. The advantages of GC-MS/MS as compared to other detection methods are tremendous in terms of sensitivity, selectivity and interpretation facilities. Limits of detection varied between 0.008 and 0.15 g kg −1 , limits of quantification between 0.025 and 0.915 g kg −1 for PAHs in food. The calibration curves showed a good linearity for all PAHs (R 2 > 0.99) and precision and recovery were fit for purpose. Trueness of the method was carried out using the US National Institute of Standards and Technology SRM 2977 reference material.

Journal of Agricultural and Food Chemistry, 2007

The volatile compounds of salmon fillets smoked according to four smoked generation techniques (s... more The volatile compounds of salmon fillets smoked according to four smoked generation techniques (smoldering, thermostated plates, friction, and liquid smoke) were investigated. The main odor-active compounds were identified by gas chromatography coupled with olfactometry and mass spectrometry. Only the odorant volatile compounds detected by at least six judges (out of eight) were identified as potent odorants. Phenolic compounds and guaiacol derivatives were the most detected compounds in the olfactometric profile whatever the smoking process and could constitute the smoky odorant skeleton of these products. They were recovered in the aromatic extracts of salmon smoked by smoldering and by friction, which were characterized by 18 and 25 odor-active compounds, respectively. Furannic compounds were more detected in products smoked with thermostated plates characterized by 26 odorants compounds. Finally, the 27 odorants of products treated with liquid smoke were significantly different from the three others techniques applying wood pyrolysis because pyridine derivatives and lipid oxidation products were perceived in the aroma profile.

Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2007

An analytical method based on gas chromatography / tandem mass spectrometry (GC-6 MS/MS) (triple ... more An analytical method based on gas chromatography / tandem mass spectrometry (GC-6 MS/MS) (triple quadrupole device) has been developed for quantification of polycyclic 7 aromatic hydrocarbons (PAHs) in smoked salmon. This method was applied to determine 8 PAH concentrations in smoked fish and to assess the impact of four industrial smoking 9 processes on their profiles. Two smokehouse temperatures and three times of smoke 10 exposure were applied. All the smoking techniques used lead to acceptable PAH levels:

Food Chemistry, 2007

The carbonyl function of volatile aldehydes is discussed from methodological point of view (react... more The carbonyl function of volatile aldehydes is discussed from methodological point of view (reactivity and analysis method). From this presentation, an inventory of volatile aldehydes recovered in smoked fishes are carried out. Then, the different pathways possible for the formation of these molecules are explained in order to better understand their occurence in smoked fish aroma. Maillard reactions for the ''smoked" aroma and lipid oxidation for ''fishy" aroma are the two main pathways of creation of odorant volatile aldehydes. Each odorant aldehyde recovered in smoked fish is characterized by its descriptors, its odour thresholds and its origins are investigated. Volatile aldehydes in smoked fishes are also studied according to the others organoleptic roles that they play in this kind of food matrices especially about their contribution in organoleptic properties of smoked products. Finally, the toxicity of several aldehydes identified in smoked fishes is discussed in order to assess their roles in smoked fish safety.

Journal of Agricultural and Food Chemistry, 2006

The odorant volatile compounds of raw salmon and smoked salmon have been investigated by two gas ... more The odorant volatile compounds of raw salmon and smoked salmon have been investigated by two gas chromatography-olfactometry methods (frequency detection and odorant intensity) and gas chromatography-mass spectrometry. After simultaneous steam distillation-solvent extraction with diethyl ether and the recovery of the aromatic extract in ethanol, qualitative olfactometric characterization and identification followed by a quantitative assessment of the odorant volatile compounds were carried out. The origin of many odorant compounds of smoked salmon can be attributed to wood smoke. Another part of smoked salmon aroma is due either to the odorant compounds of the raw fish flesh or to an evolution of fish flesh aroma thanks to the smoking process conditions. Forty-nine odorant compounds have been identified in fresh salmon and 74 in smoked salmon. Carbonyl compounds, such as heptanal or (E,Z)-2,6-nonadienal, show a high detection frequency and odorant intensity in unsmoked fish, giving the flesh its typical fishy odor. For smoked salmon, phenolic compounds, such as cresol or guaiacol, and furanic compounds seem to be responsible for the smoked odor.

Journal of Agricultural and Food Chemistry, 2008

The aroma-active compounds of cv. Turkish Kozan orange wine were analyzed by sensory and instrume... more The aroma-active compounds of cv. Turkish Kozan orange wine were analyzed by sensory and instrumental analyses. Liquid-liquid extraction with dichloromethane was used for extraction of volatile components. According to sensory analysis, the aromatic extract obtained by liquid-liquid extraction was representative of orange wine odor. A total of 63 compounds were identified and quantified in orange wine. The results of the gas chromatography-olfactometry analysis showed that 35 odorous compounds were detected by the panelists. Of these, 28 aroma-active compounds were identified. Alcohols followed by terpenes and esters were the most abundant aroma-active compounds of the orange wine. Among these compounds, ethyl butanoate (fruity sweet), 3-methyl-1-pentanol (roasty), linalool (floral citrusy), γ-butyrolactone (cheesy burnt sugar), 3-(methylthio)-propanol (boiled potato, rubber), geraniol (floral citrusy), and 2-phenylethanol (floral rose) were the most important contributors to the aroma of the orange wine because they were perceived by all eight panelists.

Food Science and Technology International, 2010

An inventory of the most part of sulfur-containing volatile compounds (SCVCs) present in seafood ... more An inventory of the most part of sulfur-containing volatile compounds (SCVCs) present in seafood was carried out. These molecules constitute key compounds to understand and improve seafood quality. According to their nature, concentration and environmental parameters (temperature), they can move the overall seafood odor from desirable to rotten. Sulfury odors can also indicate problems in sanitary quality. Thus, it is essential to monitor the generation of these compounds to better control the organoleptic and sanitary quality of seafood. SCVC were divided in two categories: aliphatic compounds and cyclic compounds. Among cyclic SCVC, several families of compounds can be distinguished as thiophenes, thiazoles and their respective derivatives. The main pathways of formation of SCVC in seafood are investigated in order to better understand their presence in seafood aroma. Microbial mediated enzymatic reactions are mainly implied in the generation of aliphatic SCVC whereas Maillard reactions are involved in the generation of cyclic SCVC. A small part of SCVC could also derive from the environment by direct bioaccumulation of S-containing molecules or precursors. Then, the occurrence of SCVC in seafood is discussed according to the extraction methods, analysis methods sometimes olfactometric methods and the species the state and the average biochemical composition of the seafood matrix in which they were recovered. Finally, among the identified SCVC, the odorant properties of odor-active volatile compounds were investigated. Aromatic notes and odorant thresholds for odorant SCVC of seafood aroma are listed. Both pathways of formation and lists of SCVC linked to their odorant properties constitute important indicators to optimise seafood quality from an organoleptic and sanitary point of view.

Food Chemistry, 2007

The representativeness of an aromatic extract of smoked salmon obtained from simultaneous steam d... more The representativeness of an aromatic extract of smoked salmon obtained from simultaneous steam distillation and extraction with diethyl ether is discussed. After extraction, the extract is diluted in ethanol with an evaporation of diethyl ether, which allows the extract to be redeposited on matrices physically similar to those of the original product. When the shift of the matrix effect is

Journal of The Science of Food and Agriculture, 2007

Four industrial processes for smoking food were studied through their effects on the organoleptic... more Four industrial processes for smoking food were studied through their effects on the organoleptic properties of smoked salmon and on the occurrence of 20 polycyclic aromatic hydrocarbons (PAHs) known as being contaminants of smoking processes. The contamination by PAHs of the food might be measured by their corresponding toxic equivalent quantity (TEQ) expressed in µg kg−1. The results show a significant correlation between the smoking process parameters, the odour of the smoked fish and the presence of PAHs. Smouldering, thermostated plates and friction smoking processes allow smoked fish with very close odorant characteristics to be obtained. However, differences of pyrolysis temperature (between 380 and 500 °C) causes significant differences of PAHs concentration even if the contents are under the legal threshold concerning benzo(a)pyrene (5 µg kg−1). Smoked fish obtained by liquid smoke vaporisation presented the lowest level of PAHs but benzo(a)pyrene concentration is nevertheless important. The odours brought by the liquid smoke process are more ‘cold smoke’ and ‘vegetal/green’ than the other techniques, which are smokier and fishier. Copyright © 2007 Society of Chemical Industry

Journal of Chromatography A, 2007

An efficient and selective analytical method for the determination and the quantification of 19 p... more An efficient and selective analytical method for the determination and the quantification of 19 polycyclic aromatic hydrocarbons (PAHs) in food and oil has been developed. This method includes the monitoring of 15 PAHs stated as a priority by the EU in their 2005/108 recommendation. The samples were extracted according to a selective extraction step using pressurized liquid extraction followed by a purification with polystyrenedivinylbenzene SPE. Identification and quantification were performed using GC-MS/MS, with an isotope dilution approach using 13 C-labelled PAHs. The novel combination of selective extraction followed by purification provides highly purified analytes combined to a fast and automated method. The advantages of GC-MS/MS as compared to other detection methods are tremendous in terms of sensitivity, selectivity and interpretation facilities. Limits of detection varied between 0.008 and 0.15 g kg −1 , limits of quantification between 0.025 and 0.915 g kg −1 for PAHs in food. The calibration curves showed a good linearity for all PAHs (R 2 > 0.99) and precision and recovery were fit for purpose. Trueness of the method was carried out using the US National Institute of Standards and Technology SRM 2977 reference material.

Journal of Agricultural and Food Chemistry, 2007

The volatile compounds of salmon fillets smoked according to four smoked generation techniques (s... more The volatile compounds of salmon fillets smoked according to four smoked generation techniques (smoldering, thermostated plates, friction, and liquid smoke) were investigated. The main odor-active compounds were identified by gas chromatography coupled with olfactometry and mass spectrometry. Only the odorant volatile compounds detected by at least six judges (out of eight) were identified as potent odorants. Phenolic compounds and guaiacol derivatives were the most detected compounds in the olfactometric profile whatever the smoking process and could constitute the smoky odorant skeleton of these products. They were recovered in the aromatic extracts of salmon smoked by smoldering and by friction, which were characterized by 18 and 25 odor-active compounds, respectively. Furannic compounds were more detected in products smoked with thermostated plates characterized by 26 odorants compounds. Finally, the 27 odorants of products treated with liquid smoke were significantly different from the three others techniques applying wood pyrolysis because pyridine derivatives and lipid oxidation products were perceived in the aroma profile.

Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment, 2007

An analytical method based on gas chromatography / tandem mass spectrometry (GC-6 MS/MS) (triple ... more An analytical method based on gas chromatography / tandem mass spectrometry (GC-6 MS/MS) (triple quadrupole device) has been developed for quantification of polycyclic 7 aromatic hydrocarbons (PAHs) in smoked salmon. This method was applied to determine 8 PAH concentrations in smoked fish and to assess the impact of four industrial smoking 9 processes on their profiles. Two smokehouse temperatures and three times of smoke 10 exposure were applied. All the smoking techniques used lead to acceptable PAH levels:

Food Chemistry, 2007

The carbonyl function of volatile aldehydes is discussed from methodological point of view (react... more The carbonyl function of volatile aldehydes is discussed from methodological point of view (reactivity and analysis method). From this presentation, an inventory of volatile aldehydes recovered in smoked fishes are carried out. Then, the different pathways possible for the formation of these molecules are explained in order to better understand their occurence in smoked fish aroma. Maillard reactions for the ''smoked" aroma and lipid oxidation for ''fishy" aroma are the two main pathways of creation of odorant volatile aldehydes. Each odorant aldehyde recovered in smoked fish is characterized by its descriptors, its odour thresholds and its origins are investigated. Volatile aldehydes in smoked fishes are also studied according to the others organoleptic roles that they play in this kind of food matrices especially about their contribution in organoleptic properties of smoked products. Finally, the toxicity of several aldehydes identified in smoked fishes is discussed in order to assess their roles in smoked fish safety.

Journal of Agricultural and Food Chemistry, 2006

The odorant volatile compounds of raw salmon and smoked salmon have been investigated by two gas ... more The odorant volatile compounds of raw salmon and smoked salmon have been investigated by two gas chromatography-olfactometry methods (frequency detection and odorant intensity) and gas chromatography-mass spectrometry. After simultaneous steam distillation-solvent extraction with diethyl ether and the recovery of the aromatic extract in ethanol, qualitative olfactometric characterization and identification followed by a quantitative assessment of the odorant volatile compounds were carried out. The origin of many odorant compounds of smoked salmon can be attributed to wood smoke. Another part of smoked salmon aroma is due either to the odorant compounds of the raw fish flesh or to an evolution of fish flesh aroma thanks to the smoking process conditions. Forty-nine odorant compounds have been identified in fresh salmon and 74 in smoked salmon. Carbonyl compounds, such as heptanal or (E,Z)-2,6-nonadienal, show a high detection frequency and odorant intensity in unsmoked fish, giving the flesh its typical fishy odor. For smoked salmon, phenolic compounds, such as cresol or guaiacol, and furanic compounds seem to be responsible for the smoked odor.

Journal of Agricultural and Food Chemistry, 2008

The aroma-active compounds of cv. Turkish Kozan orange wine were analyzed by sensory and instrume... more The aroma-active compounds of cv. Turkish Kozan orange wine were analyzed by sensory and instrumental analyses. Liquid-liquid extraction with dichloromethane was used for extraction of volatile components. According to sensory analysis, the aromatic extract obtained by liquid-liquid extraction was representative of orange wine odor. A total of 63 compounds were identified and quantified in orange wine. The results of the gas chromatography-olfactometry analysis showed that 35 odorous compounds were detected by the panelists. Of these, 28 aroma-active compounds were identified. Alcohols followed by terpenes and esters were the most abundant aroma-active compounds of the orange wine. Among these compounds, ethyl butanoate (fruity sweet), 3-methyl-1-pentanol (roasty), linalool (floral citrusy), γ-butyrolactone (cheesy burnt sugar), 3-(methylthio)-propanol (boiled potato, rubber), geraniol (floral citrusy), and 2-phenylethanol (floral rose) were the most important contributors to the aroma of the orange wine because they were perceived by all eight panelists.