- Email: [email protected]
48. The impact of dealcoholization on the flavor of wine: Relating the concentration of aroma compounds to sensory data using PLS analysis
Abstracts of Oral Presentations The aim of this study was to investigate whether measured chewing efficiency was related to characteristics of an individual’s chewing pattern. The chewing efficiency for 20 dentate volunteers was quantified by the weight loss from chewing gum after 100 chewing strokes and the particle size distribution of a whole, blanched almond chewed for ten strokes. Characteristics of the mastication patterns for each subject were measured from electromyographs (EMGs) recorded bilaterally for the masseter and anterior temporalis muscles during eating. Samples of roast beef and pork exhibiting a range of tenderness were used within the study. Four subgroups of subjects, differing in their relative efficiencies with the almond and chewing gum, were identified from the combined chewing efficiency data in terms of HiHi, LoLo, HiLo, and LoHi. Mastication parameters, determined from the EMG records, included the number of chews, total chewing time, chew rate, chew work and chew work rate for the sum of the four muscles. Analysis of variance showed that the chewing efficiency groups differed significantly in all the EMG parameters, except for chew rate, for the meat samples. The data demonstrated strong links between subjects’ chewing efficiencies with the two products and the combination of chewing time and work rate during mastication of the meat samples. The influence of these differences on perception of tenderness will be described.
47. EFFECTS OF VARIOUS FOOD TEXTURES ON HUMAN MANDIBULAR MOVEMENTS Marie-Agrks Renon,
Peyron, Laurence Mioche and Philippe
INRA, Meat Research Station, Genes-Champanelle, France
Theix 63122 Saint-
Food texture is known to influence several mastication parameters such as forces and kinematics. However, no relationship has been established between any particular texture property and its consequences on the jaw movements. This study was thus conducted to examine whether jaw movement recordings could be a reliable method to investigate food texture properties. Jaw movements were recorded in the frontal plane with an electromagnetic system. The subject’s head was placed in a magnetic field. Two receiver coils were stuck on the central incisors, one on the mandibular arch and the other on the maxillary arch for collecting head movement signals. The signal collected with the mandibular coil was corrected by subtracting head movements. To investigate the influence of texture on jaw movements, five foods were chosen to display various rheological behaviors. Chocolate represented brittle foods, two cheeses differing in hardness brought plastic fractures, meat and coconut were chosen for their fibrous character, coconut presenting a more brittle aspect. All samples were prepared in a
321
domino shape ( 1.8 x 1.8 x 1 cm3). Six replicates of each food were randomly presented. Chewing gum was used to stabilize the subject. Ten subjects free of dental pathology were asked to perform free style mastication. Durations, amplitudes and maximal velocities of opening and closing phases were measured. Jaw movement parameters allowed to discriminate the different food products. The most striking differences between products occurred with the lateral component of the jaw movement. The main finding of this experiment was the demonstration that masticatory jaw movements differed with the type of food chewed and thus this method could be of great interest for objective studies of food texture.
48. THE IMPACT OF DEALCOHOLIZATION ON THE FLAVOR OF WINE: RELATING THE CONCENTRATION OF AROMA COMPOUNDS TO SENSORY DATA USING PLS ANALYSIS Ulrich Fischer and Ralf G. Berger, Staatliche Lehr- und Forschungsanstalt, 67435 Neustadt, Germany
Breitenweg
7 1,
A total of three commercial wines were dealcoholized by vacuum distillation and reverse osmosis. Chemical (GC, GC-MS) and sensory analysis (Descriptive Analysis, GCO) investigated the base wine, both dealcoholized wines, and the respective product streams distillate and permeates. While both dealcoholization processes reduced significantly fruity odors, the musty, sweaty and vegetative attributes were enhanced. Both methods reduced perceived bitterness and aftertaste, but increased sourness. Upon adding neutral spirit to the dealcoholized wines and raising ethanol content to its original strength, all taste attributes were increased up to the level found in the base wine. In contrast, nearly all odor attributes, including the retronasal perception of fruitiness by mouth, were not altered by ethanol addition. The mass balance of aroma compounds revealed for vacuum distillation an overall reduction of 75%, which was mainly due to the transfer of esters and alcohols into the distillate. More polar lactones, phenols and short chain fatty acids however, were highly retained. Thus, boiling point and polarity mainly determined the degree of removal. In contrast, during reverse osmosis, permeation and absorption to the membrane occurred evenly across all different compound classes and accounted for 40% loss of total aroma compounds. GCO methodology employed the human nose as biological detector to select odor active aroma compounds, describe their odor quality, and determine their odor threshold by a dilution assay. Using PLS regression analysis, the chemical data set (screened according to flavor dilution values determined by GCO) was utilized to model sensory intensities. It was clearly suggested that the lack of fruitiness in
322
Abstracts of Oral Presentations
dealcoholized wines was related to the removal of esters and some odor active alcohols. The increase of vegetative, sweaty and musty flavors after dealcoholization was not associated by the generation of new or increased genuine aroma compounds, but presumably by removing masking components such as esters.
49.AROMAANALYSlSOFRASPBERRY SAMPLES BY RETRONASALSIMULATION COMBINED WITH HEADSPACEGAS CHROMATOGRAPHY-OLFACTOMETRY Deborah D. Roberts and Terry Department of Food Science University, New York State Station, Geneva, NY 14456,
E. Acree, and Technology, Cornell Agricultural Experiment USA
A flavor release method using a “Retronasal Aroma Simulator” (RAS) combined with gas chromatography olfactometry (GCO) was used to study the aroma of raspberries, rubus idaeus, cv. Heritage. Three types of raspberries were compared: fresh, heated, and heated in cream. Dynamic headspace samples were generated with the RAS with synthetic saliva addition and shearing at 37’C. A dilution series of decreasing headspace volumes (from 10 ml to 4 ~1) was sampled from the RAS using a gas-tight syringe and analyzed by CharmAnalysisrM GCO, to produce measures of odor potency called charm. The most potent flavor compounds in fresh raspberries were B-damascenone, diacetyl, sotolon, 1-hexen3-one, l-nonen-3-one, I-octen-3-one, and cis-3-hexenal, respectively. Heating increased the rated raspberry aroma by a sensory panel, and raspberry ketone produced measurable charm. Likewise, B-damascenone, 1-nonen-3-one and I-octen-3-one vanillin, sotolon, showed at least 5 fold increases in charm upon heating. Cream addition increased % fat from 0 to 6% which caused a lower raspberry aroma sensory score and a marked decrease in charm of most aroma compounds. Comparison of the fresh raspberries odor spectra between RAS-GCO and solvent extraction GCO showed
different profiles, with the former having greater odor potency values for diacetyl, 1-hexen-3-one, 1-octen-3one, 1-nonen-3-one and sotolon, and the latter with greater values for ethyl butyrate, ethyl-2-methyl butyrate and raspberry ketone.
50.SENSORYAND ELECTRONIC NOSE MEASUREMENTSOFCOLORED MALTS Alexandra Meyer, Carole Leclercq, Didier Zimmermann and Michel Rogeaux, TEPRAL, Beer Branch’s Research Center, DANONE Group, 20, Rue Jacob, 67200 Strasbourg, France
Colored malts corresponding to roasted barley green malt are commonly used in the brewery to impart color and flavor to beer. At this time, color analysis is one of the main specifications used in the quality control of this type of raw material in which chemical reactions involved in both color and flavor formation are quite complex. In order to get a better understanding and control of the flavor characteristics, we have investigated some research on colored malts using sensory analysis on malts as well as studies using an electronic nose. Measurements using the FOX 2000 device were performed on a collection of samples representing two types of colored malts. For this purpose, a combination of six sensors were selected and the experimental conditions were defined. To determine the relationships between the signal measurements and flavor characteristics, a sensory profile has been defined. Tasters have selected 21 descriptors of odor, aroma, taste, and texture to discriminate the ground malt samples. Relationships between the instrumental space and the sensory space were studied using multidimensional methods, like Principal Component Analysis (PCA), Multiple Factor analysis (MFA). Homogenous groups of malts were defined by sensory and instrumental variables in relation with the analysis of color. Within the groups, we showed many differences between the samples. The discrimination of the two methods were studied to link sensory descriptors to the electronic nose sensors.
47. EFFECTS OF VARIOUS FOOD TEXTURES ON HUMAN MANDIBULAR MOVEMENTS Marie-Agrks Renon,
Peyron, Laurence Mioche and Philippe
INRA, Meat Research Station, Genes-Champanelle, France
Theix 63122 Saint-
Food texture is known to influence several mastication parameters such as forces and kinematics. However, no relationship has been established between any particular texture property and its consequences on the jaw movements. This study was thus conducted to examine whether jaw movement recordings could be a reliable method to investigate food texture properties. Jaw movements were recorded in the frontal plane with an electromagnetic system. The subject’s head was placed in a magnetic field. Two receiver coils were stuck on the central incisors, one on the mandibular arch and the other on the maxillary arch for collecting head movement signals. The signal collected with the mandibular coil was corrected by subtracting head movements. To investigate the influence of texture on jaw movements, five foods were chosen to display various rheological behaviors. Chocolate represented brittle foods, two cheeses differing in hardness brought plastic fractures, meat and coconut were chosen for their fibrous character, coconut presenting a more brittle aspect. All samples were prepared in a
321
domino shape ( 1.8 x 1.8 x 1 cm3). Six replicates of each food were randomly presented. Chewing gum was used to stabilize the subject. Ten subjects free of dental pathology were asked to perform free style mastication. Durations, amplitudes and maximal velocities of opening and closing phases were measured. Jaw movement parameters allowed to discriminate the different food products. The most striking differences between products occurred with the lateral component of the jaw movement. The main finding of this experiment was the demonstration that masticatory jaw movements differed with the type of food chewed and thus this method could be of great interest for objective studies of food texture.
48. THE IMPACT OF DEALCOHOLIZATION ON THE FLAVOR OF WINE: RELATING THE CONCENTRATION OF AROMA COMPOUNDS TO SENSORY DATA USING PLS ANALYSIS Ulrich Fischer and Ralf G. Berger, Staatliche Lehr- und Forschungsanstalt, 67435 Neustadt, Germany
Breitenweg
7 1,
A total of three commercial wines were dealcoholized by vacuum distillation and reverse osmosis. Chemical (GC, GC-MS) and sensory analysis (Descriptive Analysis, GCO) investigated the base wine, both dealcoholized wines, and the respective product streams distillate and permeates. While both dealcoholization processes reduced significantly fruity odors, the musty, sweaty and vegetative attributes were enhanced. Both methods reduced perceived bitterness and aftertaste, but increased sourness. Upon adding neutral spirit to the dealcoholized wines and raising ethanol content to its original strength, all taste attributes were increased up to the level found in the base wine. In contrast, nearly all odor attributes, including the retronasal perception of fruitiness by mouth, were not altered by ethanol addition. The mass balance of aroma compounds revealed for vacuum distillation an overall reduction of 75%, which was mainly due to the transfer of esters and alcohols into the distillate. More polar lactones, phenols and short chain fatty acids however, were highly retained. Thus, boiling point and polarity mainly determined the degree of removal. In contrast, during reverse osmosis, permeation and absorption to the membrane occurred evenly across all different compound classes and accounted for 40% loss of total aroma compounds. GCO methodology employed the human nose as biological detector to select odor active aroma compounds, describe their odor quality, and determine their odor threshold by a dilution assay. Using PLS regression analysis, the chemical data set (screened according to flavor dilution values determined by GCO) was utilized to model sensory intensities. It was clearly suggested that the lack of fruitiness in
322
Abstracts of Oral Presentations
dealcoholized wines was related to the removal of esters and some odor active alcohols. The increase of vegetative, sweaty and musty flavors after dealcoholization was not associated by the generation of new or increased genuine aroma compounds, but presumably by removing masking components such as esters.
49.AROMAANALYSlSOFRASPBERRY SAMPLES BY RETRONASALSIMULATION COMBINED WITH HEADSPACEGAS CHROMATOGRAPHY-OLFACTOMETRY Deborah D. Roberts and Terry Department of Food Science University, New York State Station, Geneva, NY 14456,
E. Acree, and Technology, Cornell Agricultural Experiment USA
A flavor release method using a “Retronasal Aroma Simulator” (RAS) combined with gas chromatography olfactometry (GCO) was used to study the aroma of raspberries, rubus idaeus, cv. Heritage. Three types of raspberries were compared: fresh, heated, and heated in cream. Dynamic headspace samples were generated with the RAS with synthetic saliva addition and shearing at 37’C. A dilution series of decreasing headspace volumes (from 10 ml to 4 ~1) was sampled from the RAS using a gas-tight syringe and analyzed by CharmAnalysisrM GCO, to produce measures of odor potency called charm. The most potent flavor compounds in fresh raspberries were B-damascenone, diacetyl, sotolon, 1-hexen3-one, l-nonen-3-one, I-octen-3-one, and cis-3-hexenal, respectively. Heating increased the rated raspberry aroma by a sensory panel, and raspberry ketone produced measurable charm. Likewise, B-damascenone, 1-nonen-3-one and I-octen-3-one vanillin, sotolon, showed at least 5 fold increases in charm upon heating. Cream addition increased % fat from 0 to 6% which caused a lower raspberry aroma sensory score and a marked decrease in charm of most aroma compounds. Comparison of the fresh raspberries odor spectra between RAS-GCO and solvent extraction GCO showed
different profiles, with the former having greater odor potency values for diacetyl, 1-hexen-3-one, 1-octen-3one, 1-nonen-3-one and sotolon, and the latter with greater values for ethyl butyrate, ethyl-2-methyl butyrate and raspberry ketone.
50.SENSORYAND ELECTRONIC NOSE MEASUREMENTSOFCOLORED MALTS Alexandra Meyer, Carole Leclercq, Didier Zimmermann and Michel Rogeaux, TEPRAL, Beer Branch’s Research Center, DANONE Group, 20, Rue Jacob, 67200 Strasbourg, France
Colored malts corresponding to roasted barley green malt are commonly used in the brewery to impart color and flavor to beer. At this time, color analysis is one of the main specifications used in the quality control of this type of raw material in which chemical reactions involved in both color and flavor formation are quite complex. In order to get a better understanding and control of the flavor characteristics, we have investigated some research on colored malts using sensory analysis on malts as well as studies using an electronic nose. Measurements using the FOX 2000 device were performed on a collection of samples representing two types of colored malts. For this purpose, a combination of six sensors were selected and the experimental conditions were defined. To determine the relationships between the signal measurements and flavor characteristics, a sensory profile has been defined. Tasters have selected 21 descriptors of odor, aroma, taste, and texture to discriminate the ground malt samples. Relationships between the instrumental space and the sensory space were studied using multidimensional methods, like Principal Component Analysis (PCA), Multiple Factor analysis (MFA). Homogenous groups of malts were defined by sensory and instrumental variables in relation with the analysis of color. Within the groups, we showed many differences between the samples. The discrimination of the two methods were studied to link sensory descriptors to the electronic nose sensors.