bluuebunny/crossref_metadata_2025 huggingface dataset:
A CHEMILUMINESCENCE BIOSENSOR COUPLED WITH IMMUNOMAGNETIC SEPARATION FOR RAPID DETECTION OF SALMONELLA TYPHIMURIUM
Authors: VARSHNEY MADHUKAR , LI YANBIN , NANAPANNENI RAMA , JOHNSON MICHAEL G. , GRIFFIS CARL L.
Published: May 2007

A chemiluminescence biosensor, using a fiber‐optic‐linked photometer and a data acquisition unit connected to a PC, was developed in conjunction with immunomagnetic separation for rapid detection of Salmonella Typhimurium. Magnetic microbeads coated with Anti‐Salmonella antibodies and anti‐Salmonella antibodies conjugated with horseradish peroxidase (HRP) were added to artificially‐inoculated samples, and the immuno‐reaction was completed in 60 min resulting in a sandwich complex. A magnetic field was applied to collect magnetic beads and the addition of luminol to HRP‐conjugated antibodies resulted in a chemiluminescence reaction. The signal was collected through a fiber optic light guide, measured with a photometer, and recorded in the data acquisition unit. The minimum detection limit of the chemiluminescence biosensor for S. Typhimurium was 1.97 × 103 CFU/mL and the range of the detectable signal was from 8.6 to 350 mV for cell numbers from 1.97 × 103 to 1.97 × 106 CFU/mL. Signal values for 106 CFU/mL of S. Typhimurium were at least 97 and 394% higher than the corresponding values for S. enteritidis and four times the signal values for others including S. montevideo, S. california, S. heidlberg, and S. seftenberg, respectively. The biosensor response showed a significant difference (P < 0.05) between 103 CFU/mL S. Typhimurium and 106 CFU/mL of commonly‐occurring bacteria in foods including Listeria monocytogenes, Pseudomonas aeruginosa, Citrobacter freundii, Campylobacter jejuni, Escherichia coli O157, and generic Escherichia coli. A regression equation, V = 0.0262 N 5.7713, with R2= 0.9713 was obtained for the calibration curve over the detection range for S. Typhimurium. The whole procedure could be completed within 90 min.
DETECTION OF ESCHERICHIA COLI O157:H7 FROM FOOD BY A MICROPLATE SANDWICH IMMUNOASSAY USING TIME‐RESOLVED FLUOROMETRY1
Authors: YU L.S.L. , REED S.A. , TARKKINEN P. , TU S.‐I.
Published: May 2007

Escherichia coli O157:H7 has been identified as a causative agent in outbreaks of hemorrhagic colitis and hemolytic uremic syndrome involving ground beef and apple cider. A microplate sandwich immunoassay for the detection of E. coli O157:H7 from food was developed utilizing time‐resolved fluorometry. Biotin‐labeled, polyclonal anti‐E. coli O157:H7 antibodies immobilized on streptavidin‐coated microtiter plates were used to capture the bacteria. The bound antigen‐antibody complex was then detected using the same antibodies labeled with europium chelates. The effects of capture antibody concentrations, immobilization procedures, and addition of 0.1% Tween 20 to assay buffer were studied during assay development. The detection threshold for the assay developed is 103‐104 CFU/mL. The optimized assay was further tested in ground beef and apple cider samples spiked with E. coli O157:H7. The detection limit was < 10 CFU/g of ground beef and 10 CFU/mL of apple cider with 6 h of enrichment.
COMPARISON OF THE PULSIFIER AND THE STOMACHER FOR RECOVERING MICROORGANISMS IN VEGETABLES1
Authors: WU VIVIAN C.H. , JITAREERAT PONGPHEN , FUNG DANIEL Y.C.
Published: May 2007

Treatment of 30 different vegetables by the Pulsifier (30 s) and the Stomacher (60 s) showed that total viable cell counts and coliform counts were almost identical with less than 0.2 Log CFU/g difference and a ratio of ca. 1.00 between the two methods. However, the diluents from Pulsified samples were much clearer (Optical Density of 0.052), with less total soluble solids (0.30%) and slightly higher pH (6.56) than Stomached samples, which had more turbid liquid (Optical density of 0.237), with more total solids (0.55%) and lower pH (6.35). These data indicated that the Pulsifier provided equivalent viable cell count and coliform counts compared with the Stomacher from the 30 vegetables studied, but at the same time provided clearer liquid with less total soluble solid. This is advantageous for further microbiological manipulations such as Polymerase Chain Reaction, ATP evaluation, and immunological testing.
IMPEDANCE MICROBIOLOGY TO SCREEN VARIOUS ANTIMICROBIALS ON WHOLE AND FILLET CHANNEL CATFISH
Authors: SILVA J.L. , WANG C.L. , SCRUGGS M. , SILVA P.L. , KIM T.
Published: May 2007

Whole (deheaded and eviscerated) channel catfish were dipped in 1 or 2% lactic acid or sodium percarbonate (Pergenox ®). Whole and fillets were also washed with high‐pressure water or 8% sodium tripolyphosphate (STPP). Impedance detection time (IDT) was recorded for rinsates of the products. Fish dipped in 2% lactic acid had higher initial IDT than those dipped in 1 % lactic acid. Regardless of lactic acid concentration, IDT were the same in products held more than one day at 4C. Similar results were achieved for products dipped in Pergenox®. Fillets spray‐washed in STPP had higher IDT than those dipped or spray‐washed with water; the difference being pronounced after six days at 4C. For whole fish, STPP had a very significant initial reduction in microbial counts (higher IDT). Exposing the product to high‐pressure spray wash for a short time did not have a significant effect on IDT, but the addition of STPP in the water did increase IDT, thus shelf‐life.
CHALK CULTURE METHOD FOR PRESERVING BACTERIA CULTURES AND ITS APPLICATIONS1
Authors: LIU HAIJIE , FUNG DANIEL Y.C. , HOFFMANS CINDY
Published: May 2007

A simple and efficient chalk culture method was developed to preserve bacterial cultures in this study. The stability of Bacillus cereus, Enterobacter aerogenes ATCC 13048, Escherichia coli, Escherichia coli O157:H7 ATCC 43895, Listeria monocytogenes, Pseudomonas aeruginosa ATCC 25619, Salmonella Typhimurium and Staphylococcus aureus chalk cultures at 25C and 4C was evaluated at 0, 1, 2, 3 and 9 months on Tryptic Soy Agar and a specific agar for each organism. During drying process, B. cereus, E. coli O157:H7 and S. aureus chalk cultures showed less than 1.0 log CFU/g reduction, while E. aerogenes, E. coli, L. monocytogenes, P. aeruginosa and S. Typhimurium showed between 1 to 3 log CFU/g reduction. In the shelf‐life study of chalk cultures, B. cereus and E. coli O157:H7 were stable (< 1 log CFU/g reduction) at both 25C and 4C during the first 3 months. E. aerogenes, E. coli, L. monocytogenes, P. aeruginosa and S. aureus had better stability at 4C (<1 log CFU/g reduction) than 25C (<3 log CFU/g reduction) (P<0.05) during the first 3 months. S. Typhimurium was not stable at 25C and 4C during the first three months (P<0.05). From the third month to the ninth month, B. cereus, E. coli O157:H7, L. monocytogenes and S. Typhimurium were stable at both 4C and 25C (<1 log CFU/g reduction), while E. aerogenes, E. coli, P. aeruginosa and S. aureus were more stable at 4C than at 25C.

E. coli O157:H7, L. monocytogenes, S. Typhimurium and S. aureus chalk cultures were inoculated into milk, ground beef and dry pet food, and retained constant (< 1 log CFU/mL or g reduction) after 5 days storage indicating that chalk cultures are stable in these foods. For the heat treatment (55C for 5 min) study, the counts of chalk cultures in milk and ground beef reduced approximately 2 log CFU/mL or g, and about 1 log CFU/g in pet food after heating. The difference was statistically significant compared to the unheated‐inoculated sample (P<0.05). The chalk cultures are easy to prepare, stable in storage and convenient to use for challenge studies especially for dry solid food samples.
DETECTION OF STAPHYLOCOCCAL ENTEROTOXIN B (SEB) WITH SURFACE PLASMON RESONANCE BIOSENSOR1
Authors: MEDINA MARJORIE B.
Published: May 2007

An automated and rapid method for detection of staphylococcal enterotoxins is needed by the food industry. We have developed a biosensor Sandwich Assay using a surface plasmon resonance (SPR) biosensor for the detection of Staphylococcus aureus enterotoxin B (SEB). The assay is based on the immobilization of SEB antibody, capturing the SEB from the standard solutions or samples, and followed by the capture of the second SEB antibody by the sensor surface. The assay conditions were optimized to detect SEB in Hepes buffer and in ham extracts. The results indicated that SEB can be detected at 2.5 ng/mL of HBST buffer or in ham tissue extract. The calibration lines in 8 replicate analyses were determined from SEB spiked in ham extract and resulted in a mean R2 of 0.982 (SD = 0.026) and 0.995 (SD = 0.005) from SEB spiked in the supernatant of the centrifuged ham extract. Analysis of 10 and 20 ppb SEB inoculated on the surface of ham slices resulted in recoveries of 70 and 87%, and 62 and 86%, respectively, but at lower doses of 2.5 and 5 ppb SEB, the recoveries were 53, 0 and 65 and 16%, respectively. The extraction procedure can be improved to increase recoveries and the utilization of a more specific antibody can also improve the detection sensitivity. The Biacore method of analysis is semiautomated and can be developed for multi‐toxin detection in foods.
USE OF THREE RAPID DETECTION SYSTEMS TO EVALUATE THE PREVALENCE AND DISSEMINATION OFSALMONELLAIN A BRAZILIAN POULTRY SLAUGHTERHOUSE
Authors: PINTO JOSÉ PAES DE ALMEIDA NOGUEIRA , CATANEO ANGELO , LANDGRAF MARIZA , DESTRO MARIA TERESA , FRANCO BERNADETTE D.G.M.
Published: May 2007

Prevalence and dissemination of Salmonella in a Brazilian poultry slaughterhouse were evaluated by three rapid detection systems (SS/SVTM, VICAM, OSRTTM, Unipath/Oxoid, and REVEALTM, Neogen), plus the conventional procedure. The carcasses were sampled after bleeding (P1), defeathering (P2), evisceration (P3), washing (P4), chilling (P5) and the packaged end‐product (P6). In the first set of carcasses, the Salmonella incidence determined by the conventional method was 38.3% and 22.5% by SS/SVTM. In the set for evaluation of OSRTTM, the number of positive samples was the same detected by the cultural procedure (49.0%). In the third set, the positivity by the conventional procedure was 33.3%, and 5.0% by REVEALTM. The comparisons of positives in the first and third sets of carcasses were significantly different (P < 0.05). The positivity for Salmonella, in carcasses at P1 to P6, as determined by at least one of the methods, was 47.5%, 47.5%, 32.5%, 30.0%, 30.0% and 37.7%, respectively.
IMMUNO‐MAGNETIC BEAD MASS TRANSPORT AND CAPTURE EFFICIENCY AT HIGH TARGET CELL DENSITIES IN PHOSPHATE‐BUFFERED SALINE1
Authors: IRWIN PETER , DAMERT WILLIAM , TU SHU‐I
Published: May 2007

In this manuscript we present a modified kinetic model for pathogen capture efficiency (E) variation with mixing time (Tmix) which is applicable for most combinations of immuno‐magnetic bead (IMB)‐target organism concentrations (e.g., [IMB] ˜ 8 × 106 IMB mL‐1; Salmonella enterica serovar Enteritidis, [SE] ˜ 102‐108 CFU mL‐1). We found that as the ratio of [IMB] to [SE] was decreased from more than 105 to ca. 10‐1, the average number of cells captured per IMB SE complex increased from ca. 1 to 4 ± 1. Concurrently, using a modified kinetic model for fitting E variation with Tmix, the maximum possible level of capture (§) was observed to decline from ˜ 100% (§˜ 1; [IMB] > > [SE]) to 23% (§˜ 0.23; [IMB]:[SE] ˜ 0.1). Using a purely kinetic approach we also found that an empirical mass transport term (yobs= (3.1 ± 1.2) × 10‐9 mL IMB‐1 min 1; averaged across all [SE] tested: [IMB]:[SE] ˜ 200000, 200, 3, and 0.1) did not differ much from yobs reported in earlier work (3.35 ± 0.2 × 10‐9 mL min‐1 IMB‐1) at extremely low [SE] (e.g., ± 100 CFU mL‐1). Upon inserting the classically‐derived equation for γ into the kinetic model and solving for the effective IMB radius (rIMB), we found that the rIMB was 2.3 ± 0.16 μ (§ S; averaged across all [IMB]:[SE]) which was only 0.5–0.9 μ greater than the rIMB reported by the manufacturer (1.4 ± 0.2 μ). These results support previous work which showed a similar small rIMB deviation possibly due to the hydro‐dynamic behavior of the IMBs in relatively dilute buffer suspensions ([IMB ˜ 8 × 106 IMB mL‐1) and argues that IMB‐based cell capture is almost exclusively a function of mass transport.
EVALUATION OF TWO NONRADIOACTIVE GENE PROBES FOR THE ENUMERATION OF VIBRIO PARAHAEMOLYTICUS IN CRABMEAT
Authors: SLOAN E. , O'NEILL M. , KAYSNER C. , DePAOLA A. , NORDSTROM J.L. , SOFOS J.
Published: May 2007

This study evaluated two nonradioactive DNA probe procedures for the detection and enumeration of Vibrio parahaemolyticus in crabmeat by comparing counts obtained by direct plating and by most probable number (MPN) procedures. The nonradioactive probes evaluated were an alkaline phosphatase‐labeled thermolabile direct hemolysin (AP‐tdh) and a digoxigenin‐labeled thermostable direct hemolysin (DG‐tdh) for detection and enumeration of total and pathogenic V. parahaemolyticus, respectively. Inoculated samples (50 g each) of steamed crabmeat were analyzed by nine analysts in seven laboratories. Samples were inoculated with various Vibrio strains and combinations of strains at different levels of inoculation (0 to 92,000 cells/g). The results indicated that the AP‐tlh probe was reliable for identification and enumeration of total V. parahaemolyticus and the DG‐tdh probe was specific for the pathogenic strains. Both probes required less effort and expense than the biochemical testing and hemolysin assays that have previously been used. The MPN and direct plating procedures using the nonradioactive probes were both effective for enumeration of total and pathogenic V. parahaemolyticus in the absence of competing microflora, but direct plating was preferable to MPN for enumeration of V. parahaemolyticus, especially pathogenic strains, in the presence of competitors.
RAPID PROTOCOL (5.25 H) FOR THE DETECTION OF ESCHERICHIA COLI O157:H7 IN RAW GROUND BEEF BY AN IMMUNO‐CAPTURE SYSTEM (PATHATRIX) IN COMBINATION WITH COLORTRIX AND CT‐SMAC 1
Authors: WU VIVIAN C.H. , GILL VIKAS , OBERST RICHARD , PHEBUS RANDY , FUNG DANIEL Y.C.
Published: May 2007

A same day protocol for the detection of Escherichia coli O157:H7 by Pathatrix (a novel immuno‐capture method) and Colortrix (a rapid ELISA test) was developed. This study indicated that Pathatrix system, which circulated the pre‐enriched (4.5 h) samples over paramagnet beads with antibodies (0.5 h), increased the concentration of E. coli O157:H7 by 1.2–2.6 log CFU/25 g in 0.5 h from enrichment broth (modified EC broth with novobiocin or buffered peptone water). Colortrix, a rapid ELISA system, was used to detect the pathogens in another 0.25 h. Excellent correlation (100%) between positive Pathatrix/Colortrix (5.25 h system) results and positive Pathatrix/plating method with cefixime tellurite sorbitol‐MacConkey agar, with initial concentration of 0.7 to 2.1 log CFU/25 g was obtained. This new protocol offers a significant benefit to the meat industry allowing compliance with a “test” and “hold” program for E. coli O157: H7 in ground beef.
DENATURING GRADIENT GEL ELECTROPHORESIS (DGGE) AS A RAPID METHOD FOR ASSESSING GASTROINTESTINAL TRACT MICROFLORA RESPONSES IN LAYING HENS FED SIMILAR ZINC MOLT INDUCTION DIETS
Authors: RICKE S.C. , HUME M.E. , PARK S.Y. , MOORE R.W. , BIRKHOLD S.G. , KUBENA L.F. , NISBET D.J.
Published: May 2007

Induced molting through feed withdrawal can change the microenvironment of crop and ceca sufficiently to allow them to be the sites of Salmonella colonization in the chicken intestine. This study compares the denaturing gradient gel electrophoresis (DGGE) profiles of microbial crop and cecal communities among molted hens fed similar zinc acetate or zinc propionate amended molt diets to hens either undergoing feed withdrawal or hens full fed and not molted. Dendrograms of DGGE amplicon patterns indicated over 85% similarity of cecal communities between zinc acetate fed hens and zinc propionate fed hens and over 60% similarity of crop communities between zinc acetate fed hens and zinc propionate fed hens. Rapid comparison of complex gastrointestinal microflora profiles in laying hens fed similar diets is possible using DGGE.
CONTINUOUS ALCOHOL/MALOLACTIC FERMENTATION OF GRAPE MUST IN A BIOREACTOR SYSTEM USING IMMOBILIZED CELLS
Authors: AARON R.T. , DAVIS R.C. , HAMDY M.K. , TOLEDO R.T.
Published: May 2007

Three cultures immobilized by entrapping within alginate gel beads and packed in near‐horizontal acrylic columns (15.0° angle) were used for alcohol/malolactic fermentation of grape must. Immobilized cells of Saccharomyces cerevisiae spp. chablis were placed in the 1st column, S. cerevisiae cells (an alcohol‐sucrose‐tolerant yeast) in the 2nd and the Lactobacillus delbrueckii cells in the 3rd column. Grape must with different levels of sugar(s), were each fed to the bioreactor columns at dilution rate of 0.74 h−1 and recycled at 37.0C. The percent fermentation efficiency and yield using the 1st and 2nd columns for grape must containing 33.3% sugar(s) were 92.9 and 91.5%, respectively, and the wine had 15.5% alcohol after 23 cycles (∼ 50 h fermentation). The viability of the immobilized yeast cells in the alginate gel‐bead was 84%± 4.0. Immobilized Lactobacillus delbrueckii cells were then added to the 3rd column (in series 37.0C) and the three cultures resulted in alcohol/malolactic fermentation of the grape must, evidenced by the high level of alcohol formed and simultaneous transformation of malic to lactic acid. Sensory evaluation of the wine scored high (7.8 ± 2.0 based on a value of 10.0) and indicated the potential of using multiple immobilized cells of two specific yeast cultures and a malolactic Lactobacillus for wine production.
DETECTION OF VIABLE BACTERIA CELLS BY BIOLUMINESCENCE: A BIOENERGETIC APPROACH 1
Authors: TU SHU‐I , WIJEY CHANDI , PAOLI GEORGE , IRWIN PETER , GEHRING ANDREW
Published: May 2007

The cellular ATP content of fourteen freshly harvested bacteria including Bacillus, Campylobacter, Citrobacter, Escherichia, Lactobacillus, Listeria, Pediococcus, Pseudomonas, Salmonella, Streptococcus and Yersinia, was determined using a luciferin‐luciferase bioluminescence approach. Incubation of bacteria with carbonyl cyanide meta‐chlorophenyl hydrazone (CCCP), a membrane protonophore, prior to cell breakage substantially lowered the bioluminescence signals indicating a decrease of cellular ATP content. The addition of CCCP after cell breakage had no detectable effect on the ATP levels. This differential effect of CCCP was not observed using heat‐killed bacteria, i.e., the ATP content was not affected by CCCP incubation. The CCCP effects on cellular ATP level were detectable in bacterial suspensions with concentrations ranging from 106 to 103 CFU/mL. Upon cold storage, the ATP content, but not the population of viable bacteria, decreased. The ATP content could be partially restored by the addition of glucose. The ATP content restored by the addition of glucose was also sensitive to CCCP treatment. These results demonstrated that viable bacterial cells can be differentiated from dead cells by their responses to membrane protonophores.
EVALUATION AND APPLICATIONS OF ODOR PROFILING
Authors: JELTEMA M.A. , SOUTHWICK E. W.
Published: May 2007

An odor profiling procedure was developed based on the ASTM odor profiling method. This modified procedure involved using approximately twenty panelists. Panel sessions and data collection were controlled by computer. The results obtained by this panel compared favorably to results obtained by the ASTM panel for which 150 panelists evaluated each compound, indicating that a small panel can be used to produce replicable results. Statistical methods of finding similarities and dissimilarities among compounds using profile data are discussed and compared to results from a multidimensional scaling (MDS) study in which degrees of differences among compounds were judged directly. These results indicate that profile data can be used to define and map the degree of similarity/dissimilarity among compounds, as well as to define the sensory dimensions on which these compounds differ. The use of factor analysis to study the underlying sensory dimensions of the odor space is also discussed. It is hoped that this type of research will lead to a better understanding of the underlying dimensions used to describe odorants.
USE AND ABUSES OF CATEGORY SCALES IN SENSORY MEASUREMENT
Authors: RISKEY DWIGHT R.
Published: May 2007

Category ratings are a popular device for assessing preferences and for guiding efforts in the development of new products. They are frequently misinterpreted or misused, however, because their use is so closely analogized to the process of fundamental measurement. Unlike physical measures, psychological scales such as category ratings are strongly affected by situational or contextual factors which must be carefully controlled and fully understood for proper use of the scale. Category ratings are affected by stimulus range and frequency, number of stimuli and number of categories, as well as by stimulus sequence. Implications for appropriate use of the scale in sensory evaluation are addressed.
SENSORY ADAPTATION
Authors: O'MAHONY MICHAEL
Published: May 2007

Sensory evaluation makes use of the remarkable virtuosity and range of the human senses as a multi‐purpose instrument for measuring the sensory characteristics of foods. The brain protects itself from an overload of information from the senses by two processes: feature extraction and adaptation. The former involves information reduction by the extraction of selected features from the environment; these form the basis for the reconstruction of the percept in consciousness. The latter, adaptation, involves the attenuation of repetitive and constant input so as not to overload the brain with redundant information.

The effects of adaptation can be observed for all senses. For the chemical senses, the effect is that a constant odor or taste stimulus will be perceived as decreasing in intensity while sensitivity to that stimulus is also decreased. For sensory evaluation, this poses problems. It means that a taste or odor has a tendency to vanish while it is being observed and that sensitivity to subsequent stimuli will be altered. Such sensitivity drift in the human instrument must be anticipated in the design of measurement procedures for the sensory evaluation of food.

For taste, adaptation changes caused by the measurement method can be seen to be largely responsible for disagreements in the literature concerning threshold and intensity measurement. Adaptation is also a contributing factor, but by no means the only one, in determining the relative discriminability of sensory difference tests. It is worth noting, however, that adaptation is not always a disadvantage; it can sometimes be used to advantage in sensory testing procedures.
DEVELOPMENT OF CHICKEN FLAVOR DESCRIPTIVE ATTRIBUTE TERMS AIDED BY MULTIVARIATE STATISTICAL PROCEDURES1
Authors: LYON B.G.
Published: May 2007

Chicken patties (50% light/50% dark meat) were used as training and testing samples by a 10‐member panel to develop descriptive terms appropriate for profiling the taste/aroma character notes of fresh and reheated chicken meat. A free word association list of 45 terms was developed in initial training sessions. These terms were used to obtain frequency of use and intensity data for statistical analyses to determine appropriateness of the terms for profiling and discriminating among fresh and reheat treatments of the chicken patties. The initial list was reduced to 31 terms by a frequency‐use delimiter of 40% over four replications and by MANOVA probability values (P > .05) for sample differences. FACTOR (principal components) analysis applied to the reduced list of terms indicated six logical associative groupings of terms that explained 77% variation in the data. A final list of 12 descriptors was developed by omitting redundant terms in a factor grouping.
SOME ISSUES IN THE DESIGN AND ANALYSIS OF SENSORY DATA: REVISITED
Authors: GACULA MAXIMO.
Published: May 2007

Sensory experimental data whether collected via the consumer or via the laboratory population have many characteristics in common. Among the more important characteristics are that they are relative, skewed, and difficult to replicate. These characteristics result from the use of human beings as instruments to measure multivariate stimuli as opposed to the use of a mechanical instrument. The use of human beings as instruments presents several problems in the design and analysis of sensory/consumer studies. In the clinical/medical applications of sensory evaluation, we have used people both as the experimental unit (panelists/subjects) and as the instrument (judges) to measure panelists’ responses. Thus it is my belief that sensory data are the most difficult scientific data to statistically analyze and interpret.

Unfortunately, limited theoretical work has been done to tackle the resulting problems. These problems include the comparison of responses obtained from independent populations (monadic design), sample size estimation with special reference to time‐dependent responses, analysis of degree of difference data, the invariance property of rating scales, effect of correlated errors in observations, and the use of laboratory panels to predict results from a consumer panel. Some solutions to these problems have been provided by experience. My purpose here is to discuss each of these problems in greater detail and offer some possible scientific solutions.
INTENSITY VARIATION DESCRIPTIVE METHODOLOGY: DEVELOPMENT AND APPLICATION OF A NEW SENSORY EVALUATION TECHNIQUE
Authors: GORDIN HARVEY H.
Published: May 2007

The Intensity Variation Descriptive Methodology (IVDM) is a modification of the descriptive analysis procedure commonly used in the sensory evaluation of foods. The IVDM technique provides multiple attribute evaluations within specified sections of a product sample. In this study, the IVDM technique was used to quantify changes in attribute intensity as a cigarette sample was consumed.

A touch sensitive Hewlett Packard 150 Personal Computer was used as the data collection instrument. Proprietary software was developed which created a graphic representation of an unstructured line scale on the computer screen. Subjects indicated the intensity of sensory attributes, within various sections of tobacco rod, by touching the computer screen anywhere along the line scale. Data obtained from IVDM evaluations indicated that this method was sensitive to the quantitative changes in cigarette smoke components during consumption of the product.

The program developed for IVDM testing may be modified for conventional descriptive testing. The application of computers as sensory evaluation data collection instruments was explored.
A REAPPRAISAL OF THE USE OF MULTIDIMENSIONAL SCALING TO INVESTIGATE THE SENSORY CHARACTERISTICS OF SWEETENERS
Authors: THOMSON DAVID M.H. , TUNALEY ANNE. , VAN TRJJP HANS C.M.
Published: May 2007

Previous investigations of the sensory characteristics of sweeteners using a multidimensional scaling (MDS) approach, have involved sweeteners which were not matched for sweetness. Under such circumstances, part of the estimated distance between sweeteners is attributable to sweetness differences. This detracts from the value of the consequent MDS space, when the main objective is usually to investigate sensory characteristics other than sweetness. In this study, the MDS approach was applied to sweetener solutions which were matched for sweetness with 5% sucrose. The direction of any residual sweetness differences was identified by including 1,3,5 and 7% sucrose solutions, all matched to equal viscosity, in the study. From the resulting three dimensional MDS sweetener space, it was evident that Dimension 1 was almost exclusively due to sweetness differences whereas Dimensions 2 and 3 were devoid of influence from sweetness and hence represent the sweeteners with respect to their other sensory characteristics.
EVALUATION OF RANGE‐GRAZED AND CONCENTRATE‐FEDBEEF BY A TRAINED SENSORY PANEL, A HOUSEHOLD PANEL AND A LABORATORY TEST MARKET GROUP
Authors: MEDEIROS L.C. , FIELD R.A. , MENKHAUS D.J. , RUSSELL W.C.
Published: May 2007

A trained sensory panel and a household panel evaluated leaner range‐grazed and higher grading concentrate‐fed beef for sensory characteristics. The findings were compared to those from a laboratory test market study designed to determine the consumer appeal of branded range‐grazed beef when compared to concentrate‐fed beef. Broiled steaks from concentrate‐fed steers were scored more flavorful, more tender, more juicy and more desirable overall than those from range‐grazed steers by the trained sensory panel and by the household panel. In the laboratory test market study steaks from range‐grazed steers were nearly equal in acceptance to those from concentrate‐fed steers because consumers, although accustomed to concentrate‐fed beef in their marketplace, compromised palatability for meat they perceived to be leaner and more healthful.
SITE TO SITE VARIATION IN THE SOAP CHAMBER TEST
Authors: FINKEY M.B. , GACULA M.C. , MILLER J.K.
Published: May 2007

This investigation was conducted to examine the contribution of intrasite variation on the volar forearm to the overall variation in irritation under the conditions of a soap chamber test. Six sites on each forearm of human volunteers were patched with an eight percent aqueous solution of a commercial bar soap, known to be moderately irritating. Clinical evaluations of the sites were made independently by two judges twenty‐four hours after the first patch application and six hours following applications conducted over the next four consecutive days. Site to site variability was estimated to be only 3.2% of the total variance component. It is suggested that as with any biologic assay, this variance can be reduced by an increase in the number of panelists.
A COMPARISON OF VARIABLE REDUCTION TECHNIQUES IN AN ATTITUDINAL INVESTIGATION OF MEAT PRODUCTS
Authors: GAINS N. , KRZANOWSKI W. J. , THOMSON D. M. H.
Published: May 2007

In many attitudinal investigations, particularly those involving free‐choice profiling, a very large list of variables or features can emerge. Ordination using generalized Procrustes analysis provides a common base for comparing assessors, but the derived configurations are often high‐dimensional and difficult to summarize. This problem can be rectified by selecting a small subset of the original set of variables. Methods of variable selection in principal component analysis can be adapted easily for such purposes, but there is no guarantee with these methods that overall data structure is preserved. A recently introduced variable selection procedure that does aim to preserve the data structure as much as possible would seem to be more appropriate. All methods are described and applied to a set of data arising from an attitudinal investigation of meat products. The results indicate that variable selection should be more widely encouraged.
FLAVOR THRESHOLDS FOR VANILLIN AND PREDICTIONS OF HIGHER OR LOWER THRESHOLDS
Authors: POWERS JOHN J. , SHINHOLSER KATHLEEN.
Published: May 2007

Thesholds for vanillin dissolved in water were determined first by 32 panelists, then by 100 additional panelists. Extreme‐value analysis was applied to the results from the first 32 determinations to estimate the likelihood of thresholds later encountered being even lower than those already detected. No threshold among the 100 additional determinations was below the 5% confidence limit for the regression curve based on the 32 determinations originally made. There was evidence that some panelists were ageusic to vanillin in aqueous solution. Although some investigators have suggested that the frequency distribution for threshold values of vanillin is bimodal, application of the Kolmogorov‐smirnov test to the distribution of the 132 values, as natural logarithms, gave little cause to reject the hypothesis that the distribution was unimodal.
THE PANELIST EFFECT – FIXED OR RANDOM?
Authors: LUNDAHL D.S. , McDANIEL M.R.
Published: May 2007

The theoretical and practical aspects of how panelists might be viewed are investigated. The situation where panelists are viewed as random selections (random effects) from a population of all possible panelists is compared to viewing panelists as the entire population of interest (fixed effects). The statistical implications of each viewpoint are investigated. Sources of variation related to the panel, panelists and the testing environment are discussed. An argument is presented concluding that in most situations panelists should be viewed as random effects. This allows results to be related to a larger population of prospective panelists.
DEVELOPMENT OF AN ACCEEPTABILITY CONSTRAINT FOR A LINEAR PROGRAMMING MODEL IN FOOD FORMULATION
Authors: BEAUSIRE ROBERT L.W. , NORBACK JOHN P. , MAURER ARTHUR J.
Published: May 2007

Control of a product's market acceptability can be a difficulty when using linear programming models in food formulation. The development of an acceptability constraint was demonstrated for a linear programming model used for the formulation of fresh turkey bratwurst, a coarse ground type sausage. Development was in two stages. First, an experimental design and in‐house panel determined quantitative relationships between the product's textural attributes and turkey meat ingredients. Second, the product toughness relationship was utilized to develop three formulations with different levels of toughness. These formulations were market tested using the acceptor set size as the measure of market acceptability. A relationship between product toughness and acceptor set size was determined, into which was substituted the toughness f (ingredients) relationship. This yielded acceptor set size as a f (ingredients) that was added to the least cost linear programming model in the form of an acceptability constraint.
SENSORY STRATEGY FOR SUCCESS IN THE FOOD INDUSTRY
Authors: EGGERT JEAN.
Published: May 2007

Fully integrating sensory resources with related business units represents a challenge for the sensory professional. As sensory evaluation provides actionable information in a timely, cost effective manner, developing resources that are consistent with corporate plans and impact on decision‐making is essential. This discussion focuses on developing a sensory strategy for success and highlights strategic planning techniques designed to maximize sensory evaluation's contribution to the accomplishment of a company's mission.
FUZZY SET THEORY APPLIED TO PRODUCT CLASSIFICATION BY A SENSORY PANEL1
Authors: WESTENBERG H. W. LINCKLAEN. , De JONG S. , von MEEL D. A. , QUADT J.F.A. , BACKER E. , DUIN R.P.W.
Published: May 2007

It is frequently impossible to meet the assumptions underlying the statistical approach to classification of food products by a sensory panel. To find an alternative, we have investigated the applicability of the fuzzy set theory. Within a fuzzy set framework it is acceptable that a product belongs to several classes simultaneously and no assumptions regarding the distribution of sensory properties for a product class are made. Fuzzy classification models can be constructed from a set of training objects by linking the soft class labels to the sensory attributes applying an inference procedure based on fuzzy logic. A number of fuzzy inference procedures has been evaluated using a number of attribute sets. A satisfactory classification has been found using a very simple implication rule and a set of three attributes.
AROMA PROPERTIES AND THRESHOLDS OF SOME BRANCHED‐CHAIN AND OTHER MINOR VOLATILE FATTY ACIDS OCCURRING IN MILKFAT AND MEAT LIPIDS1
Authors: BRENNAND CHARLOTTE P. , HA J. KIM. , LINDSAY ROBERT C.
Published: May 2007

Aroma properties of twenty‐three branched‐chain, odd‐numbered, or unsaturated fatty acids which had each been dispersed in acidic aqueous media (pH 2.0) were evaluated. Aroma threshold values were determined using approximately 95 judges for assessing the presence of aromas over dilutions of each fatty acid. Qualitative aroma threshold values for individual fatty acids ranged from 0.006 to 82.4 ppm in the acidic solutions, and 4‐ethyloctanoic acid exhibited the lowest threshold of the group tested. Qualitative aroma assessments of dilutions of each fatty acid showed a wide range of unique aroma properties. Fatty acids exhibiting branching at the 4‐position had goaty/muttony/sheepy aroma notes as did other fatty acids containing 8‐carbon chain structures. Cheese‐like aromas were associated with the shorter branched‐chain fatty acids.
EFFECTS OF EXTERNAL FAT COVER, BONE REMOVAL AND ENDPOINT COOKING TEMPERATURE ON SENSORY ATTRIBUTES AND COMPOSITION OF PORK CENTER LOIN CHOPS AND ROASTS
Authors: SIEMENS A. L. , HEYMANN H. , HEDRICK H. B. , KARRASCH M. A. , ELLERSIECK M. , EGGEMAN M. K.
Published: May 2007

Effects of fat cover, bone removal and endpoint cooking temperature on proximate and sensory characteristics of pork center loin chops were investigated. Only brown color of broiled chops was affected by presence of bone and by endpoint temperature. Fat cover only affected perceived chewiness of chops. Broiled boneless chops contained higher percent fat than bone‐in chops. There were no differences in protein, fat or moisture percentages in cooked chops due to fat cover. Higher internal temperature decreased percent moisture and increased percent protein. Percent fat did not differ due to internal temperature. A consumer study to determine the degree of liking of pork center loin roasts showed that consumers preferred roasts with no fat cover more than roasts with 0.6 cm fat cover and roasts cooked to 71.1°C compared to roasts cooked to 76.7°C. There was no difference in preference between boneless and bone‐in roasts.
SEQUENTIAL MONADIC DESIGNS: SOME THEORETICAL CONSIDERATIONS
Authors: KOMANSKA HENRYKA.
Published: May 2007

When choosing a design for estimating product differences we must consider both the appropriate model for the analysis of results and the economic aspects of the test. If no residual effects are expected the SMD design provides an efficient way of estimating the product difference. If the residual effect is known to be present it is better to consider an alternative design. The choice of an alternative will depend on both theoretical (desired precision of estimates) and practical (cost of conducting a study) considerations. In this paper, I review both the theoretical underpinnings of SMD and some of its possible alternatives.
EXPLORATION OF THE SENSORY CHARACTERISTICS OF CRAVED AND AVERSIVE FOODS
Authors: BLANK DEIDRE M. , MATTES RICHARD D.
Published: May 2007

This research examined the sensory characteristics of craved and aversive foods, as determined by 70 healthy adults. Cravings and aversions were identified by 66% and 53% of subjects. Typically, cravings were intermittent, and the items were sweet tasting and pleasant smelling. In contrast, aversions were chronic, and the items were described as either bitter or bad (e.g., soapy, mealy, dusty) tasting, and exhibiting an unpleasant smell. Chemesthetic attributes were frequently associated with cravings and aversions, particularly texture and thermal sensations with the former whereas texture and irritating sensations were associated with the latter. The findings suggest that sensory characteristics of foods may provide salient cues for the formation of cravings and aversions.
PRODUCT OPTIMIZATION IN CENTRAL‐LOCATION TESTING AND SUBSEQUENT VALIDATION AND CALIBRATION IN HOME‐USE TESTING
Authors: GRIFFIN ROBERT. , STAUFFER LAURA.
Published: May 2007

A dry‐powdered soft drink was optimized in a central‐location test wherein consumers used a fifteen‐point liking scale to rate six different products in a sequential monadic fashion. A consumer liking surface was modeled from this taste test evaluation. Four formulations predicted to be differentially accepted from the central‐location test were fielded in a paired‐preference home‐use test to validate the sequential monadic central‐location test and to calibrate the fifteen‐point liking scale into a preference metric. The results showed remarkably good agreement across the two methods. These findings add strength to the idea that a central‐location test that utilizes multiple product evaluations for each consumer can be effectively used to guide the product development process.
CONSULTANT'S CORNER PROPOSING THE INTERNATIONAL SENSORY JUDGES DAY
Authors: HOUGH GUILLERMO. , MARTINEZ EDGARDO. , CONTARINI ADRIANA. , BARBIERI TERESA.
Published: May 2007

A panel of trained sensory judges is a sensitive and valuable instrument. and a lot of time and work is invested in their selection and training. The importance of internal motivation and external stimulation to maintain the interest and wellbeing of these human instruments is supported by major food scientists and behavioral psychologists. Current stimulation procedures for sensory judges are listed. A new procedure is proposed, consisting of an annual celebration party on November 20 in recognition of sensory judges. Advantages of holding this day on an international level are discussed: mainly, promotion of fellowship among sensory judges from different groups and countries, and also its help in increasing cooperation in sensory evaluation. Actions to promote International Sensory Judges Day are listed. Suggestions for the actual celebration party are put forward: an open house luncheon, presentation of awards, greeting cards and letters from other sensory panels; and last but not least, a set of proven “sensory” games where everyone joins in.
CONSUMER PREFERENCE OF DULCE DE LECHE AMONG STUDENTS IN THE UNITED KINGDOM
Authors: HOUGH GUILLERMO. , BRATCHELL NICHOLAS. , WAKELING IAN.
Published: May 2007

Dulce de Leche is a dairy‐based confectionary product virtually unknown outside Latin America. A 24 factorial design was implemented to study the influence of sugar composition, type of neutralizer, cooking time and presence of vanilla essence on the preference of Dulce de Leche by UK university students. A fractional factorial pattern was used in sen'ing samples to assessors. Analysis of variance showed that the preferred levels were: 40% replacement of sucrose by glucose syrup, 100% sodium bicarbonate as neutralizer, and no vanilla essence. Cooking time did not significantly affect preference. Partial least squares regression was used to relate preference to sensory profile scores. The correlation was good for appearance and texture, not so for flavor and aftertaste. A mapping technique showed consumers to be uniformly grouped for appearance and texture, not so for flavor. Results from preference and general acceptability were encouraging in promoting this new dairy product in Great Britain.
PERFORMANCE ASSESSMENT OF SENSORY PANELISTS
Authors: MANGAN PATRICIA A. PRITCHETT.
Published: May 2007

The replication variance of individual stimulus evaluations and scale utilization across a panelist's stimulus profile are simultaneously employed to develop statistics for assessing performance of panelists. The approach provides opportunities for comparison of panelists to each other, determination of attributes for which panelist confusion is observed, isolation of stimuli presenting unstable properties, and engagement of influence weights (based on relative precision) in subsequent analyses of data. Although the methodology has been developed for applications involving sensory panelists, the statistical concepts may be extended to other data collection scenarios involving replicated determinations from bounded quantitative measurement scales.
UNDERSTANDING MOUTHFEEL ATTRIBUTES: A MULTIDIMENSIONAL SCALING APPROACH
Authors: BERTINO MARY , LAWLESS HARRY T.
Published: May 2007

Multidimensional scaling (MDS) was used to study qualitative relationships among mouthfeel attributes encountered in oral healthcare products. Similarity estimates were obtained from a rapid sorting task and from pairwise similarity ratings. Configurations were interpreted as suggesting four groupings of oral sensations: numbing, astringency, pain and taste. The pain‐associated sensations were further differentiated into thermally related sensations and chemically related sensations in some configurations. Two‐dimensional solutions from the sorting task and from group‐averaged similarity ratings were similar. Individual differences scaling solutions, however, showed unacceptably high stress in two dimensions, suggesting additional nuances in meaning to individual panelists that were not captured by group‐averaged data or by sorting data.
EFFECTS OF A SLIGHT COLOR VARIATION ON CONSUMER ACCEPTANCE OF ORANGE JUICE
Authors: TEPPER BEVERLY J.
Published: May 2007

Three hundred and forty‐two consumers participated in a study examining slight color variation in orange juice. Panelists evaluated two orange juice samples; unadulterd juice and the same juice with a slight green off‐color. The color manipulation reduced consumer acceptance of the color of the adulterated sample but had little influence on ratings of flavor, sweetness or overall liking. Older panelists were more strongly influenced by the color manipulation and showed a clear preference for the flavor of the control sample as compared to the adulterated sample. These data suggest that color was important for the visual appeal of orange juice, but the color change alone was not sufficient to alter consumer acceptance of this product.
TIME‐INTENSITY EVALUATION OF ORAL BURN1
Authors: CLIFF MARGARET , HEYMANN HILDEGARDE
Published: May 2007

Temporal oral burn profiles for cinnamaldehyde, piperine and capsaicin were quantified using time‐intensity (TI) parameters. Despite large judge‐to‐judge variation, TI profiles for eaters and noneaters of chile peppers differed significantly. Eaters had lower maximum intensities, shorter total times, and slower maximum rates of onset and decay. Judges with substantial desensitization also had shorter time‐to‐maximum intensities. Desensitized judges not only scored the burn of capsaicin as less intense, but also the burn of cinnamaldehyde and piperine. The burn of cinnamaldehyde solutions increased and decayed quickly; whereas, burns due to piperine and capsaicin increased and decayed slowly. Capsaicin compared to cinnamaldehyde, had time‐to‐max, plateau time, and total time that were 1.5, 2.0 and 3.0 fold larger; whereas, the maximum rates of onset and decay were 0.7 and 0.2 fold smaller, respectively. Temporal differences are believed to reflect differences in neural pathways for the irritant species.
THE MEASUREMENT OF TASTE DISCRIMINATION WITH THE SAME‐DIFFERENT TASK: A DETECTION‐THEORY ANALYSIS
Authors: IRWIN R. JOHN , STILLMAN JENNIFER A. , HAUTUS MICHAEL J. , HUDDLESTON LYNNE M.
Published: May 2007

The biases to which the same‐different task is prone can be accounted for by having subjects rate their confidence that two stimuli are the same or different. The rating method of detection theory was therefore used to study the discriminability of two concentrations of a fruit drink. A model in which the decision variable was the difference in sensory strength of the two samples provided a satisfactory fit to the Receiver Operating Characteristics of four of the five subjects. The bias‐free index of discriminability, d′, was estimated for each subject. A combined operating characteristic, derived from jackknifing the data of the individual subjects, revealed an asymmetry characteristic of the differencing model. The results suggest that the same‐different task, which is readily understood by subjects, can provide an unbiased measure of the discriminability of foods or beverages.
WHAT SENSORY CHARACTERISTICS DRIVE PRODUCT QUALITY? AN ASSESSMENT OF INDIVIDUAL DIFFERENCES
Authors: MOSKOWITZ HOWARD , KRIEGER BERT
Published: May 2007

Consumers differ dramatically in their sensory preferences for products. This paper assesses the relative importance of appearance, taste/flavor and texture as characteristics that drive acceptance for a complex pie product. The paper classifies consumers as being driven by one or more sensory attributes in their judgment of product quality. To do so, each consumer's liking rating is regressed against each separate attribute liking. The coefficient (M) of the linear equation “Overall Liking = M (Attribute Liking) + B″ measures the relative importance of the sensory attribute as a driver of overall quality.