bluuebunny/crossref_metadata_2025 huggingface dataset:
PRESENCE OF VIRULENCE PLASMID IN YERSINIA ENTEROCOLITICA AFTER ITS EXPRESSION AT 37C1
Authors: BHADURI SAUMYA
Published: May 2007

The phenotypic characteristics associated with the virulence plasmid in Yersinia enterocolitica are expressed only at 37C, a temperature which facilitates the loss of the plasmid. This report investigated the stability of the virulence plasmid in Y. enterocolitica after its phenotypic expression at 37C. Polymerase chain reaction analysis of plasmid DNA showed that Y. enterocolitica did not loose the virulence plasmid during phenotypic expression as assayed by crystal violet binding, Congo red uptake, low calcium response, hydrophobicity and autoagglutination at 37Cfor 24 h. Prolonged incubation of at least 48 h at 37C is needed to trigger the loss of the plasmid.
THE USE OF BACTERIAL MEMBRANE FRACTIONS FOR THE DETECTION OF CAMPYLOBACTER SPECIES IN SHELLFISH
Authors: ABEYTA C. , TROST P.A. , BARK D.H. , HUNT J.M. , KAYSNER C.A. , TENGE B.J. , WEKELL M.M.
Published: May 2007

Selected enrichment broths supplemented with the enzyme Oxyrase a membrane‐bound enzyme derived from E. coli were evaluated for recoveries of Campylobacter under normal atmospheric conditions from shellfish. Results indicate that Oxyrase is useful for the recovery of Campylobacter from shellfish. Effect of Oxyrase on growth of Campylobacter were dependent upon physical parameters such as media volume and surface volume area. For example, in the comparision of growth of Campylobacter sp (low to high levels, 1 × 101 to 6/mL) in various media volumes in Stomacher 400 closure bags and 250 mL and 500 mL screw‐capped Erlenmeyer flasks, no campylobacters were recovered using the closure bags. However, all levels of Campylobacter were recovered in the Erlenmeyer flasks. Oxyrase was useful for the recovery of C. jejuni from Pacific oysters (Crossostrea gigas). In one study, Pacific shellstock oysters were allowed to take up 1 × 106 cells of C. jejuni per mL for a period of 5 to 7 h in an artificial seawater aquarium system. Oysters were removed and stored at 4C for 24 days. Uptake in oysters ranged from 0.4 to 114 cells/g. At intervals, oysters were removed and analyzed for C. jejuni by using the Oxyrase method and the FDA/Bacteriological Analytical Manual standard method. Comparison of these methods showed that the Oxyrase method was as reliable as the official FDA method. Oxyrase was also useful for recovering naturally occurring Campylobacter in market oyster shellstock. To measure reproducibility of the method, an in‐house preliminary collaborative study was conducted in the University of Central Venezuela (Caracas). Participants consisted of 6 groups of three microbiologist each from various countries in Central and South America. All groups were successful in recovering Campylobacter jejuni and Campylobacter coli using Oxyrase. Our results indicate that Oxyrase provides microaerobic conditions for growth of Campylobacter from shellfish.
A NONLINEAR RESPONSE SURFACE MODEL BASED ON ARTIFICIAL NEURAL NETWORKS FOR GROWTH OF SACCHAROMYCES CEREVISME1
Authors: HAJMEER M.N. , BASHEER I.A. , FUNG D.Y.C. , MARSDEN J.L.
Published: May 2007

Response surface models (RSMs) are used to predict microbial growth as a function of environmental conditions. This study aimed to (1) develop an artificial neural network (ANN) model for predicting the combined effect of pH, and ethanol [E], and fructose [F] concentrations on the growth of Saccharomyces cerevisiae, (2) compare the prediction accuracies of ANN and traditional RSM, and (3) determine the relative importance of the three environmental factors in affecting growth of S. cerevisiae. Data used to construct the network were obtained from a literature study in which RSM were developed using linear regression techniques for estimating the growth rate constant (μmax). A total of 59 data sets representing the growth of S. cerevisiae in relation to pH, [E], and [F] was utilized. The agreement between experimental and ANN‐predicted values for the growth parameter (μmax was assessed quantitatively using three statistical descriptors: the Mean of the Absolute values of the Relative Error (MARE), coefficient‐of‐determination (COD) and sum‐of‐squared‐errors (SSE). The developed ANN‐based RSM. predicted the μmax of S. cerevisiae with higher accuracy than regression‐based RSM. The differentiability of the neural network provided means for studying the sensitivity of the model output (In μmax to each input parameter averaged over the entire database. The μmax was found to be most sensitive to pH, followed by [E], and [F] concentrations.
APPLICATION OF GENE AMPLIFICATION IN CONJUNCTION WITH A HYBRIDIZATION SENSOR FOR RAPID DETECTION OF SALMONELLA SPP. AND FECAL CONTAMINATION INDICATORS IN ANIMAL FEEDS
Authors: MACIOROWSKI K.G. , PEÑA J. , PILLAI S.D. , RICKE S.C.
Published: May 2007

The rapid detection of pathogenic microbial species in feed is of paramount importance considering its implications for animal production and food safety. To demonstrate the feasibility of rapidly detecting Salmonella spp. and fecal pollution microbial indicators in feed using gene amplification protocols, commercial and mixed feed samples were inoculated with two levels of a marker strain of S. typhimurium. Liquid extracts of the feed samples were used as templates in gene amplification reactions to amplify sequences associated with fecal contamination indicators. The sequence specificity of the amplification products (amplicons) were confirmed using biotin and fluorescein labeled probes in a navel dual probe based hybridization sensor. Using the combination of gene amplification and the hybridization sensor, the presence of sequences associated with fecal contamination were detected in 15 different feed matrices without employing preenrichment steps. Using this detection methodology, fecal pollution can be confirmed in feed at naturally occurring concentrations. The study demonstrates that it is possible to rapidly detect and confirm the presence of pathogenic bacterial genera in feed matrices by combining robust gene amplification reactions with appropriate post amplification detection systems.
ASSESSMENT OF IMPEDANCE MICROBIOLOGICAL METHOD FOR THE DETECTION OFESCHERICHIA COLIIN FOODS
Authors: JAWAD GHAZALA M. , MARROW TODD , ODUMERU JOSEPH A.
Published: May 2007

This study was conducted to determine the sensitivity and specificity of the impedance‐based microbiological method for the detection ofEscherichia coliin foods within 24 h of testing. A Malthus Microbiological Analyzer system (Malthus System V, Malthus Instruments Ltd., Bury, United Kingdom), and a modified Malthus Coliform Broth Medium (MCBM), and an incubation temperature of 44C were used. The sensitivity of the impedance method was determined by testing E. coli‐negative food samples spiked with different concentrations ofE. coli.The specificity of the method was determined by testingE. coli‐negative food samples spiked withKlebsiella pneumoniae, Enterobacter cloacaeandPseudomonas aeruginosa.The test results were compared with those obtained by the Most Probable Number (MPN) method. Milk, milk products, raw and ready‐to‐eat meats, and vegetables were tested for the presence ofE. coliby both methods. The sensitivity of the impedance method and the MPN method for the detection of foods containing 101CFU/g was 100% and 84.4%, respectively. Both methods had a specificity of 100% for food samples spiked with 101CFU/gE. coli.The specificity of the impedance and the MPN methods for the detection ofE. coliin naturally contaminated milk and meat samples was 100% and 95.7% respectively.E. coliwas detected in foods by the impedance method within 4–24 h of testing at a detection limit of 1 CFU/mL. These results demonstrate that the impedance method can be used as a rapid and sensitive method for the detection ofE. coliin foods.
A MODIFIED GAUSS‐NEWTON ALGORITHM AND NINETY‐SIX WELL MICRO‐TECHNIQUE FOR CALCULATING MPN USING EXCEL SPREADSHEETS1
Authors: IRWIN P. , TU S. , DAMERT W. , PHILLIPS J.
Published: May 2007

Conventional most probable number (MPN) methods seek a calculated value for microbial concentration (Δ, mL‐1) which induces the total binomial probability function (Ptotal) to approach its maximum limit. In fact, such techniques are the only statistically compelling procedures available for determining MPN when utilizing a small set of observations per dilution (e.g., n = 3–8). However, as n approaches a large value, statistical routines which assume a normal distribution might be applied to ascertain the MPN. With this in mind, we produce herein a modified Gauss‐Newton “linearization” (curve fitting) algorithm for determining Δ (n = 96) from binomial micro‐plate assays which are readily automated using 96‐well micro‐plate readers. This technique, an iterative protocol, is less cumbersome than many traditional MPN procedures and has certain advantages. Data derived from this method were not only close to MPN estimations using a direct technique based on the conventional maximum probability resolution (MPR) concept but also displayed more favorable chi‐squared (X2) statistics.
USING CONVENTIONAL MICROTITER PLATE TECHNOLOGY FOR THE AUTOMATION OF MICROBIOLOGICAL TESTING OF DRINKING WATER
Authors: WALSER P.E.
Published: May 2007

With the arrival of automated systems for microtiter (MT) plate assays, classical most probable number (MPN) techniques lend themselves to an efficient way to perform quantitative microbiological tests. In contrast to existing automated systems for quantitative determination of microorganisms there is no need for dedicated instruments. Standardized MT equipment available in modern biochemical laboratories, namely a pipetting robot using sterile pipetting tips and a MT reader under computer control are the only prerequisites. The distribution of the media and the samples with optional dilutions, the measurement of growth as well as the statistical calculations of the MPN value are performed automatically. A system was validated for the analysis of the aerobic mesophilic count (AC) of drinking water. The system can cope with low or high bacterial load from 0 to 2 × 104 colonies per mL. The system which takes out the tedium and personnel influence of routine microbiological work is prone to many other determinations like fecal indicator organisms in water as well as other microorganisms of interest in food microbiology.
USE OF PCR ANALYSIS FOR STERILITY TESTING IN PHARMACEUTICAL ENVIRONMENTS
Authors: JIMENEZ LUIS , IGNAR RAYMOND , D'AIELLO ROBERT , GRECH PAUL
Published: May 2007

To determine the sterility of pharmaceutical samples, highly conserved bacterial ribosomal DNA sequences were used in a PCR‐based assay. Finished products, raw materials, growth media, and diluents were artificially contaminated with different types of microorganisms. Samples were incubated for 24 h. After incubation, microbial DNA was extracted from enrichment broths using a Tris‐EDTA‐Tween 20 buffer containing proteinase K. Extracted DNA was added to Ready‐To‐Go PCR beads and eubacterial primers. Contaminated samples were found to contain the conserved 1.5 kilobase (kb) DNA fragment of the bacterial genome by using the PCR assay. None of the uninoculated samples was found to show the presence of the 1.5 kb fragment. PCR test results were compared with standard conventional methods. There was a 100% correlation between standard conventional methods and the PCR assay. However, the PCR‐based assay was completed within 27 h while conventional methods required 4–5 days. Rapid PCR analysis using a simple sample preparation reduced the time for sterility testing of pharmaceutical samples allowing optimization of risk assessment and implementation of corrective actions.
ESTIMATION OF MICROBIOLOGICAL QUALITY OF CHILLED BEEF USING AUTOMATED TURBIDIMETRY
Authors: MASANA MARCELO O. , MEICHTRI LELIS H. , RODRÍGUEZ H. RICARDO , NEIRA M. SUSANA
Published: May 2007

Total bacterial counts on chilled beef samples were estimated by the standard plate count method and by an automated turbidimetric system. The latter method is based on product‐specific calibration curves constructed by correlating growth curve parameters calculated for the turbidimeter to the log CFU values obtained by plate counts. A total of 74 beef samples was used to construct the calibration curves. Correlation analysis between turbidimetric parameters and plate count values showed that detection time was the best predictor to estimate microbial loads on fresh (r=0.91) and aged beef (r=0.94). Microbial loads for a different set of aged beef samples (n = 37) refrigerated for 7, 9, 10, 17 and 45 days were compared by turbidimetric measurements and plate counts. Mean total viable counts were log 5.92 ± 1.17 and log 5.54 ± 1.28 CFU/mL, respectively. Results showed that total bacterial counts on chilled beef could be estimated accurately from turbidimetric parameters. Furthermore, setting a cut‐off value of log 6 CFU/mL allowed to accepting/rejecting samples according to their microbial condition in shorter periods of time compared to the traditional plate count method.
EVALUATION OF THE PETRIFILMTM AND REDIGELTM AS RAPID METHODS TO THE STANDARD PLATE COUNT METHOD FOR THE ENUMERATION OF PROCESSED MEATS AND ENVIRONMENTAL SAMPLES
Authors: SCHMELDER JENNIFER L. , KALINOWSKI ROBIN M. , BODNARUK PETER W.
Published: May 2007

Aerobic plate counts (APC) are used by the food industry to help determine the sanitary state of equipment and bacterial load of finished product. Conventional aerobic count methods for processed meats require approximately 72 h incubation before results are available. Food processing plants with in‐house analytical laboratories require methods that are simple, reliable and rapid. New test methods using PetrifilmTM (PF) and RedigelTM (RG) have been developed for determining APC. These methods are faster and easier than culturing in a standard agar medium. A variety of raw, cooked; cured and noncured meat products, cooling brine and environmental surface swabs were collected and analyzed for APC using PF, RG and plate count agar (PCA). Data analyses from over 200 samples indicated that the sensitivity of rapid testing methods for aerobic bacteria can vary depending on sample type.
SIMPLE AND RAPID METHOD FOR SCREENING ANTIMICROBIAL ACTIVITIES OF BIFIDOBACTERIUM SPECIES OF HUMAN ISOLATES
Authors: IBRAHIM SALAM A. , SALAMEH MAYSOUN M.
Published: May 2007

The objective of this research was to develop a rapid procedure for the screening antimicrobial activities of Bifidobacterium species of human isolates. A bifidobacteria selective medium BIM‐25 agar was modified by adding of 0.5 g/L cysteine‐hydrochloride, 1.5 g/L lithium chloride, 1.0 g/L beef extract, and 5 mL/L Tween 20. This medium was inoculated (45C) with diluted fecal material from 5 subjects and overlaid into 0.1% Tween 20 BHI agar plates. Plates were incubated in anaerobic chamber at 37C for 48 h. Plates were then inverted to allow the two layers of agar to fall into the petri lid. BHI soft agar (0.45%) containing Micrococcus luteus (as indicator) was overlaid onto the other layers in the petri dish. Plates were incubated at 37C overnight and zone of growth inhibition was observed. This method is simple and rapid whereas the original method for screening of antimicrobial activities of bifidobacteria is a more time consuming and cumbersome procedure.
EVALUATION OF BEADRETRIEVERTM, AN AUTOMATED SYSTEM FOR CONCENTRATION OF ESCHERICHIA COLI O157 FROM ENRICHMENT CULTURES BY IMMUNOMAGNETIC SEPARATION
Authors: CHAPMAN P.A. , CUDJOE K.S.
Published: May 2007

The aim of this study was to compare automated immunomagnetic separation (AIMS) with manual IMS (MIMS) for detection of E. coli O157 in natural and artificially inoculated samples. E. coli O157 was isolated from 27 (14.7%) of 184 natural bovine fecal samples by MIMS and from 26 (14.1%) by AIMS. Of 94 natural carcass samples, E. coli O157 was isolated from 6 by both MIMS and AIMS and from a further 6 by AIMS only. Three of the six positive only by AIMS were from tubes processed adjacently to one containing an inoculated sample and strains isolated from these adjacent tubes were indistinguishable by various typing techniques. Of the 36 carcass samples inoculated with E. coli O157, the organism was isolated from 25 by both MIMS and AIMS and from a further 9 by AIMS only. To process 100 samples by MIMS took 5h whereas by AIMS this took only 3h 20 min which represented a considerable saving of staff time.
IMMUNO‐MAGNETIC BEAD MASS TRANSPORT AND CAPTURE EFFICIENCY AT LOW TARGET CELL DENSITIES IN PHOSPHATE‐BUFFERED SALINE1
Authors: IRWIN PETER , DAMERT WILLIAM , BREWSTER JEFFREY , GEHRING ANDREW , TU SHU‐I
Published: May 2007

Anti‐salmonella immuno‐magnetic bead (IMB) capture efficiency (E) was determined by varying both IMB levels ([IMB]) and mixing time (TMIX) and enumerating captured Salmonella enteritidis cells. We observed that E varied with TMIX as a Pseudo‐first order process with a rate constant (K) of 0.028 ± 0.001 min‐1 and an infinite TMIX asymptote of 0.97 (97% capture). Thus, even at low target cell densities ([S. E.] ± 70 CFU mL‐1), nearly 100% of the bacteria were captured as TMIX approached 2 h. We hypothesize that k is the product of both IMB mass transport (γ) and IMB concentration ([IMB]) terms. Thus, γ represents the total volume which each IMB samples per unit time of mixing. This idea appears reasonable as γ(3.2 ± 0.2 × 10‐9mL min‐1 IMB‐1), determined from E‐based observations at various [IMB] levels (˜106−108 IMB mL‐1) and fixed TMIX (30 min), was nearly identical to γ(3.5 ± 0.1 × 10‐9 mL min‐1 IMB‐1) derived kinetically (TMIX= 0–120 min; [IMB] = 8 × 106 IMBs mL‐1). Estimating a mass transport term (γCALC) founded on classical dynamics we obtained a value 5.3 × 10‐10 mL min‐1 IMB‐1 whereupon γCALC and γ would have completely agreed were the IMB radius (rIMB= 1.4 μm) 0.8 μm larger. The apparent discrepancy in rIMB might be explained by a greater effective (hydrodynamic) rIMB which could result from some combination of IMB swelling and brownian motion. These results argue that IMB‐based target cell capture is modulated by IMB mass transport and collision probability.
DETECTION OF ESCHERICHIA COLI O157 IN RAW BEEF USING A CCD BASED LIGHT SCATTERING INSTRUMENT
Authors: WANG R.Y. , LIOW E.W.M. , KEAY P.J.
Published: May 2007

A sensitive and easy‐to‐perform instrumentational method for the detection of Escherichia coli O157 in raw minced beef is described. The detection is based on a light scattering immunoassay and a charge‐coupled device (CCD) direct readout spectrometer measuring the scattered light spectral signals at an optimized angle of 20° to the axis of transmitted light. Using latex particles coated with antibodies for E. coli O157, the method sensitivity has significantly improved comparing with the visual immunoassay assessment method when detecting the presence of this bacterium in spiked beef samples. The method is capable of detecting E. coli O157 at the level of 103 cfu mL‐1 after 6 h of incubation of the spiked samples. This study has demonstrated a faster technique (within 8 h) for the detection of E. coli O157 in raw beef and a possible new application for the CCD based light scattering instrument.
INFLUENCE OF OXIDATION‐REDUCTION REDUCTANTS ON SALMONELLA TYPHIMURIUM GROWTH RATES AFTER INITIAL pH ADJUSTMENT AND ZINC COMPOUND ADDITION
Authors: PARK S.Y. , WOODWARD C.L. , BIRKHOLD S.G. , KUBENA L.F. , NISBET D.J. , RICKE S.C.
Published: May 2007

The objective of this study was to examine the separate influence of acidic pH, reductants (cysteine and sulfide) and zinc compounds (Zn acetate and Zn sulfate) during anaerobic growth of a S. typhimurium poultry isolate in rich or minimal media. The anaerobic growth of a S. typhimurium poultry isolate in TSB medium was significantly inhibited by either acidic initial pH or higher concentrations of Zn acetate. S. typhimurium anaerobic growth in M9 minimal medium was significantly inhibited by either acidic pH or higher concentrations of Zn acetate or Zn sulfate. Most anaerobic growth rates of the S. typhimurium poultry isolate in acidic media and with higher concentrations of Zn acetate or Zn sulfate were less than 0.10 h‐1. The overall anaerobic growth rates of S. typhimurium were inhibited more in the presence (0.089 h‐1) of reductants than in the absence (0.102 h‐1) of reductants in M9 medium. Results in this study suggest that either increasing Zn concentration or decreasing initial pH can reduce growth rate of foodborne Salmonella under anaerobic growth conditions.
RAPID METHOD OF CHEESE PROCESSING FOR MICROFLORA AND MICROSTRUCTURAL STUDIES BY ELECTRON MICROSCOPY 1
Authors: ARYANA KAYANUSH J. , HENK MARGARET C.
Published: May 2007

Previous methods for cheese sample processing for electron microscopy involves several days. Our objective was to identify a suitable yet rapid method. The rapid method involved an initial fixation of cheese in a solution of 2% glutaraldehyde and 1% OsO4 in 0.05M cacodylate buffer for 10 min. This was followed by a second fixation in 2 % glutaraldehyde and 2 % OsO4 in 0.05M buffer for an additional 20 min. Sample fixation by the rapid method was attained in a total of 30 min compared to 17 h in the control, i.e., the previous method, which required 15 h (overnight) fixation in 1% glutaraldehyde and 2 h fixation in 1 % OsO4. After fixation, en block staining with aqueous uranyl acetate was conducted for 30 min. This was followed by ethanol dehydration and infiltration in resin. Additionally, the rapid method was conducted with LR White resin compared to Spurr's epoxy resin in the control. The culture bacteria, protein matrix and dispersed fat globules were clearly visible and were unaltered by the rapid method.
THE DISRIMINATIVE EFFICIENCY OF COMMON SCALING METHODS
Authors: LAWLESS HARRY T. , MALONE GILBERT J.
Published: May 2007

Four types of rating scales, nine‐point category scales, line marking, magnitude estimation, and a hybrid of the category and line scale, were employed to assess visual, tactile and olfactory characteristics of products by consumers. The scales were compared for their ability to discriminate differences among products, for variability, for reliability, and for ease of use. All methods were able to generate highly significant differences among products. However, a modest advantage for category scales was observed in almost all comparisons.
A STANDARDIZED LEXICON OF MEAT WOF DESCRIPTORS1
Authors: JOHNSON PETER B. , CIVILLE GAIL VANCE
Published: May 2007

A new descriptive language for evaluating the taste of warmed‐over meat flavor has been developed. These terms should help researchers elucidate the causes of the phenomena of off‐flavor in meats. The meat industry should also be able to apply these terms in new meat product development, quality control, and shelf‐life stability.
EFFECTS OF HEALTH DISORDERS AND POOR NUTRITIONAL STATUS ON GUSTATORY FUNCTION
Authors: MATTES RICHARD D.
Published: May 2007

Gustatory function is not static within an individual. Taste sensitivity and preferences are modified by numerous, well‐documented external factors (e. g. smoking) as well as less widely recognized physiologic or internal idiosyncratic attributes such as salivary composition and genetic make‐up. In addition, no single gustatory attribute adequately characterizes an individual's taste world. Measures of threshold sensitivity, suprathreshold sensitivity and preference may vary independently necessitating the assessment of each to derive a reliable assessment of an individual's gustatory status. Measures of taste preference, however, appear to hold the greatest predictive power for dietary behavior. Gustatory disorders may be manifest in the following forms: hypergeusia, hypogeusia, dysgeusia, ageusia, food aversions and food cravings. Each of these disorders is defined and, to the extent that information is available, the prevalence, etiology and clinical significance of each is discussed. Following this, a general scheme is presented along with numerous examples for evaluating the potential impact health or nutritional disorders may have on gustatory function. Finally, implications of health and nutritional disorders for applied sensory research are briefly considered.
PRODUCT OPTIMIZATION AND THE ACCEPTOR SET SIZE
Authors: LAGRANGE VERONIQUE , NORBACK JOHN P.
Published: May 2007

The acceptability of a product, measured by the acceptor set size (percentage of consumers rating the product acceptable), is a function of the perception of its attributes. The attributes are themselves a function of the inputs to the product (such as ingredients, processing or storage variables). These assumptions lead to the following model:

Acceptor set size = F (attribute1, attribute2, …, attributen)

Attribute j = f (input1, input2, …, inputm)

If we assume that these functions are differentiable, we can estimate the partial derivatives of the acceptor set size, with respect to the input variables. The gradient vector obtained indicates the fastest way to maximize the acceptor set size. The gradient search method, using the acceptor set size as an objective measure, can be applied in a variety of situations: to improve existing products, to maximize the acceptability of new products, and to study the relationship between shelf‐life and acceptability.
ALTERNATIVE ANALYSES OF MAGNITUDE ESTIMATION DATA
Authors: BUTLER G. , POSTE L.M. , WOLYNETZ M.S. , AGAR V.E. , LARMOND E.
Published: May 2007

Three methods of standardizing magnitude estimation data, external calibration, modulus normalization, and equalization were examined using a sensory evaluation data set arising from an incomplete block experiment testing five gels of varying firmness. Both the original data and a logarithmic transformation of the data were analyzed. Instrumental data were also collected. When untransformed data were analyzed the method of standardization profoundly affected tests of significance, coefficients of variation (%CV), and estimation of the power function relating the sensory data to the concentration of the underlying gel. The logarithmically transformed data lead to results independent of the standardizing technique and with higher F‐ratios, lower %CV's and normally distributed errors.
THE RELATIONSHIP BETWEEN CONSUMER PREFERENCES AND TRAINED PANEL RESPONSES
Authors: SHEPHERD R. , GRIFFITHS N. M. , SMITH K.
Published: May 2007

Eight samples of dried tomato soups were profiled by a trained panel, who also provided ratings of overall liking and liking for particular attributes on relative‐to‐ideal rating scales. A consumer panel tested a subset of four of the soups in home trials, assessing them for overall liking and for particular attributes on either hedonic or relative‐to‐ideal rating scales.

The pattern of overall preferences differed between the trained and untrained panelists, demonstrating the inappropriateness of using trained panelists to provide measures of preference or acceptance. The conclusions regarding consumer preferences would differ depending on which rating scale was used; these differences disappeared when the relative‐to‐ideal ratings were converted into values of the same form as the hedonic ratings. The overall liking was best predicted by flavor rather than color or thickness.

A principal components analysis (PCA) of the profile data compared well with a plot based on the trained panel preference data using MDPREF. The preference data were also fitted to the PCA dimensions using the PREMAP vector model, which gave a good fit for only six of the 15 trained panelists; the PREMAP ideal point model failed to show a better fit. In order to test these models adequately more than eight samples would need to be tested.
CONTRASTING THE EFFECTS OF INGESTION AND EXPECTORATION IN SENSORY DIFFERENCE TESTS1
Authors: KELLY F. B. , HEYMANN H.
Published: May 2007

Paired comparison and triangle tests were used to contrast the effects of ingestion and expectoration in two distinct systems: added salt in kidney beans and nonfat milk with added milkfat. Probit analysis was used to determine panel difference thresholds. Analysis of variance was used to evaluate significant differences between the methods of sampling and for effects of fatigue due to ingestion of the sample. No significant differences between the two methods of sampling were found for either thresholds or fatigue effects.
EFFECTS OF SAMPLE SIZE AND PRIOR MASTICATION ON TEXTURE JUDGMENTS
Authors: CARDELLO ARMAND V. , SEGARS RONALD A.
Published: May 2007

Two experiments were conducted. In the first, 25 untrained subjects judged the hardness and chewiness of three different food samples following either 0, 60, 120, or 180 s of adaptive chewing on an experimental gum compound. No effect of the adaptive chewing was found, in spite of observable and self‐reported masticatory fatigue induced by the experimental procedures. These data fail to support the prevalent use of procedural limits on the number and temporal spacing of samples in sensory texture studies. In the second experiment, six groups of subjects (n = 107) judged the hardness and chewiness of two series of food samples that varied in physical size (volume). The groups differed in the degree to which cues about the true size differences were made available. Results showed both hardness and chewiness judgments to increase as a function of sample size, independently of subject awareness of the size differences. These data support the use of procedural controls on sample size, but fail to provide evidence of a size constancy phenomenon. A rheological explanation is proposed to account for the observed sensory effect.
DESIGNS TO BALANCE THE EFFECT OF ORDER OF PRESENTATION AND FIRST‐ORDER CARRY‐OVER EFFECTS IN HALL TESTS
Authors: MACFIE HALLIDAY J. , BRATCHELL NICHOLAS. , GREENHOFF KEITH. , VALLIS LLOYD V.
Published: May 2007

The problem of balancing out the effect of order of presentation and the carryover effect of a preceding sample over a series of presentations of the same set of samples is addressed. A series of designs developed by Williams (1949) are used. The method of calculation is given. Tables containing about 50 consumers of each design for presenting from 4 through to 16 samples are given.
INFLUENCE OF SELECTED MARKETING FACTORS ON CONSUMER RESPONSE TO RESTRUCTURED BEEF STEAKS: A CONJOINT ANALYSIS1
Authors: CHENG H. W. , CLARKE A. D. , HEYMANN H.
Published: May 2007

Restructured beef steaks, formulated with different beef particle sizes, fat content and binder levels, were evaluated with selected marketing factors by 30 consumers. Conjoint analysis was applied to consumers’hedonic scores and statement of purchase intent for raw and cooked steaks. Product preference, packaging and brand had significant (P < 0.05) impacts on hedonic scores for raw products. Price was an additional important factor in purchase intent. Parcooked products, only product preference was important for both hedonic rating and purchase intent. When products were not present, conjoint measurement indicated that nutritional information, price and brand influenced (P < 0.05) hedonic responses.
DEVELOPMENT OF SAS® COMPUTER PROGRAMS FOR SENSORY GRAPHICS1
Authors: CLIFFJ M. , WILD J. S.
Published: May 2007

Graphics programs were developed using SAS® (Statistical Analysis System) for descriptive analysis sensory data. The routines allow the operator to generate publication quality polar coordinate plots (“cobweb” diagrams), and principal component plots from simple data files.
THE POWER FUNCTION OF CARBONATION
Authors: YAU N. J. NEWTON. , MCDANIEL MINA R.
Published: May 2007

The relationship between the physical carbonation level of carbonated spring water and the magnitude of carbonation perception was determined by a trained panel using two assessing conditions, swallowing and expectoration. Spring water was carbonated to 5 carbonation levels. Panelists were asked to rate their perception of carbonation intensity by using magnitude estimation. The power function equations were established with high correlation coefficients for both assessing conditions. The exponents, 2.79 (swallowing) and 2.65 (expectoration), suggested a sharp increase of perceived CO2 magnitude with increasing concentration. There was no significant difference between exponents resulting from the two assessing conditions. Therefore, the response should not be affected if samples are expectorated in studies of carbonation perception.
USE OF CHEMICAL SENSOR ARRAYS FOR FOOD AND FRAGRANCE ANALYSIS
Authors: HOFFHEINS B. S. , LAUF R. J.
Published: May 2007

Many workers have recently developed and demonstrated the use of gas sensor arrays to detect and recognize a variety of compounds. In general, a pattern recognition approach is used in which the signature of an unknown sample is compared to a library of signatures of known substances. All of these efforts have shown varying degrees of success when applied to pure compounds. Unfortunately, flavors and fragrances are never pure compounds. A prototype gas sensor array has been constructed and tested with various mixtures of interest. The results are discussed in terms of their implication to the food and fragrance industry.

Early experiments on gasoline‐alcohol mixtures demonstrated that the signatures do not follow a rule of mixing, but were more strongly influenced by the more volatile and/or more reactive component. This led us to examine the behavior of alcohol‐water mixtures for possible quality control in the distilling industry. We discovered that the signature of alcohol dominated even at concentrations as low as ten percent. Preliminary experiments were also performed to see if the prototype sensor array could be used to automatically detect rancidity in dairy products.

Flavorings and essential oils are in many cases even more complex mixtures. The behavior of representative classes of these substances were characterized in an attempt to understand their signatures on the basis of their constituents.
A STATISTICAL TEST OF CONSENSUS OBTAINED FROM GENERALIZED PROCRUSTES ANALYSIS OF SENSORY DATA
Authors: KING BONNIE M. , ARENTS PAUL.
Published: May 2007

Matrix matching techniques such as Generalized Procrustes Analysis (GPA) always produce a matrix of maximal agreement which can then be used to graphically represent samples in “consensus plots”. The degree to which the consensus plots produced by GPA on sensory data (such as that obtained from free choice profiling) actually give a picture of true consensus among panelists, as opposed to being merely artifacts of the analysis, has not been examined. Using a Monte Carlo approach, a statistical test is defined for qualifying this consensus. Examples of the application of the test to sensory profiling data of fruit flavors are given.
SENSORY ASPECTS OF MATURATION OF CHEDDAR CHEESE BY DESCRIPTIVE ANALYSIS
Authors: PIGGOTT J. R. , MOWAT R. G.
Published: May 2007

Previous research on the flavor development of Cheddar cheese has largely concentrated on the chemical changes that occur, and less work has been published on the sensory aspects of cheese maturation. Cheddar cheese was produced under controlled conditions and a quantitative descriptive analysis procedure was developed and used to assess development of sensory properties during maturation. The method was successful and weekly changes were recorded during maturation. The sensory data also grouped cheeses according to commercial classifications such as Vintage, Mature and Medium, and showed how these were related to a reduced fat cheese. The quantitative descriptive analysis procedure could be used in conjunction with other chemical and physical methods to help in gaining a full understanding of the maturation process in Cheddar cheese.
SENSORY‐SPECIFIC SATIETY FOR SELECTED BREAD PRODUCTS1
Authors: JOHNSON JILL. , VICKERS ZATA.
Published: May 2007

Subjects rated the intensities of 42 different attributes for 26 different bread products. Principal component analysis was used to categorize the breads based on their attribute ratings. The first two principal components were interpreted as a richness dimension and a nutrition/fiber dimension. The influence of these dimensions on sensory‐specific satiety in bread products was investigated.

Subjects tasted and rated their liking of small portions of a set of bread products representative of the extremes of the richness dimension and the nutrition/fiber dimension before and after eating a 400 calorie serving of one of the breads. Measurements of hunger were taken before and after the meal.

Bread appeared resistant to sensory‐specific satiety. The richness of the breads did not affect the amount of sensory‐specific satiety. The high nutrition/fiber breads decreased hunger and tended to decrease liking more than the low nutrition/fiber breads.
LEARNED FLAVOR CUES INFLUENCE FOOD INTAKE IN HUMANS
Authors: TEPPER BEVERLY J. , MATTES RICHARD D. , FARKAS BECKY K.
Published: May 2007

These studies examined the influence of learned flavor cues on daily food intake in 28, normal‐weight adults. Subjects were trained to associate distinctly flavored high or low calorie lunches with their postingestive effects. Following training, the flavors in the lunches were switched. Twenty‐five percent of subjects (responders) adjusted their daily food intake based on their acquired sensory experience and were initially misled by the changes in the flavor cues; i.e., following the flavor switch, responders consumed additional or fewer calories based on the expected rather than actual energy intake of the meals. Energy intake gradually returned to baseline levels. The remaining subjects (nonresponders) were not misled by the flavor switch and maintained their customary level of intake. Responses were more pronounced following conditioning with the high calorie as compared to the low‐calorie lunch. These data suggest that sensory cues may play an important role in the control of long‐term food intake in individuals who are sensitive to such training.
CONTROL CHART TECHNIQUE: A FEASIBLE APPROACH TO MEASUREMENT OF PANELIST PERFORMANCE IN PRODUCT PROFILE DEVELOPMENT
Authors: GATCHALIAN MIFLORA M. , DE LEON SONIA Y. , YANO TOSHIMASA.
Published: May 2007

A quality control chart technique was tested for feasibility in measuring panelist performance in product profile development. The descriptive sensory score sheet evolved by Filipino trained panelists for fresh‐frozen young coconut meat and water at “malakanin”(7–8 months old coconut fruit) stage was utilized for this study. A comparison of panelist performance in terms of their congruence, within themselves and between each other, in identifying the intensity or presence of an attribute was made. Results indicated that a similar measurement of significant differences could be obtained using both the analysis of variance (ANOVA) approach and the control chart (c.c.) technique. Considering the volume of data to be handled, the c.c. technique appeared to be more manageable than ANOVA. Besides, the c.c. was found by the panelists and the researchers to be more interesting to analyze, easier to apply, to interpret and to use for improvement follow‐through compared to the ANOVA.
DESCRIPTIVE ANALYSIS OF ORAL PUNGENCY1
Authors: CLIFF MARGARET , HEYMANN HILDEGARDE
Published: May 2007

Pungent spices are well‐recognized for their aromatic and pungent nature; however, relatively little is known about their pungent or ‘burning’ responses. Therefore, this research was undertaken to characterize oral pungency of the principal irritants or red pepper (capsaicin), black pepper (piperine), cinnamon (cinnamaldehyde), cumin (cuminaldehyde), cloves (eugenol), ginger (ginger oleoresin), and alcohol (ethanol). These compounds were evaluated for four pungent qualities (burning, tingling, numbing, overall), two temporal qualities (lag time, overall duration), and three spatial qualities (longitudinal location, lateral location, localized/diffuse). The pungency of cinnamaldehyde was primarily burning and tingling. It had a quick onset and rapid decay. The pungency of eugenol had a long‐lasting, predominantly numbing effect. The pungency piperine, capsaicin and ginger were primarily burning, but had different temporal and spatial responses. The pungency of ethanol was most diffuse in nature, with some burning and tingling sensations. It had the shortest perceived onset and overall duration. The pungency of cuminaldehyde was equally burning, tingling and numbing.
UNDERSTANDING DISCRIMINATION TESTS: A USER‐FRIENDLY TREATMENT OF RESPONSE BIAS, RATING AND RANKING R‐INDEX TESTS AND THEIR RELATIONSHIP TO SIGNAL DETECTION
Authors: O'MAHONY M.
Published: May 2007

Aproblem central to sensory difference testing is response bias. There are two experimental strategies for dealing with this problem. The first is to use forced choice procedures, like the common duo‐trio or triangle tests, while the second is to use signal detection measures like d′, P(A) and the R‐index. These strategies are explained and discussed. The relationship between the R‐index and the other signal detection measures is explained. The relationship between R‐index values obtained by rating and ranking is explored, as are the alternative computations of the R‐index by ranking: Rjb and Rmat.
A STATISTICAL APPRAISAL OF THE PROBLEM OF SENSORY MEASUREMENT
Authors: GAY C. , MEAD R.
Published: May 2007

The problem of sensory measurement has been tackled using a wide range of methods, from sophisticated systems of scaling to simple ranking. This paper focuses on the problems arising from the fact that the units of sensory scales are frequently arbitrary. It looks at alternative methods of scale design and statistical analysis as a response to the problem and, in particular, introduces a novel combination of scale design and statistical analysis, which may be collectively described as a self‐adjusting scale method. The self‐adjusting scale method has particular appeal when there is little opportunity for the training of panelists in the use of a particular sensory scale and, though it was originally developed and evaluated in the context of laboratory assessment, may actually have its greatest application in the realm of consumer testing.
REDUCING THE NOISE CONTAINED IN DESCRIPTIVE SENSORY DATA
Authors: BETT K.L. , SHAFFER G.P. , VERCELLOTTI J.R. , SANDERS T.H. , BLANKENSHIP P.D.
Published: May 2007

A data reduction protocol was designed to minimize distortion inherent in sensory data. Following removal of nonexistent attributes and treatment levels, extreme value analysis and distribution comparisons combined with graphical respresentations, facilitated elimination of inconsistent (with respect to overall consensus) panelists. Application of a calibration factor showed superresponsive panelists (those with intensity values consistently higher than other panelists) were among the most accurate and thus were retained in spite of their tendency to produce extreme value data. Panelists that consistently produced a narrow variance around the overall mean and rarely produced extreme values were classified as noncomittal and removed. Analysis of variance calls for a split plot design; blocks (sessions) and treatments in main plot, and panelists in subplot. In general, the subplot can be ignored. These methods are suggested for evaluating panelists’ training needs; and for eliminating data that distorts the statistical analysis.
RELATIONSHIPS BETWEEN BITTER TASTE SENSITIVITY AND CONSUMPTION OF BITTER SUBSTANCES
Authors: TANIMURA SHUYA , MATTES RICHARD D.
Published: May 2007

The effect of consumption of bitter taste substances (caffeine and beer) to bitter taste sensitivity was examined by 19 healthy adults. For individual taste sensitivity, detection thresholds were used on 6 bitter substances (caffeine, iso‐alpha‐acids: beer bittering agents, quinine sulfate, L‐tryptophan, L‐phenylalanine and glycyl‐L‐phenylalanyl‐L‐phenylalanine) and 3 non‐bitter substances (L‐aspartic acid, aspartame and NaCl). Nonusers of caffeine had significantly higher sensitivity (lower threshold) for caffeine compared to moderate and heavy users. Slight consumers of beer had significantly higher sensitivity for iso‐alpha‐acids relative to heavy users of beer, Iso‐alpha‐acids were not detected in saliva in acute dosing test by using 6 subjects. The correlations between thresholds of 6 bitter substances were calculated. Significant correlations (p < 0.01) were noted in 2 cases between caffeine and quinine, and iso‐alpha‐acids and L‐trypothan. These data suggest the significant relation between individual bitter taste sensitivity and the consumption of caffeine and beer (iso‐alpha‐acids).
DETERMINATION OF THE SENSORY FLAVOR ATTRIBUTES OF AGED NATURAL CHEESE1
Authors: HEISSERER DELORES M. , IV EDGAR CHAMBERS
Published: May 2007

A highly trained, descriptive sensory panel identified, defined, and referenced 30 flavor attributes for cheese. The attributes generally could be described as dairy‐like (buttery, cooked milk, dairy‐fat, dairy‐sour, dairy‐sweet); fatty‐acid/animal (animalic, butyric, decaying animal, fresh fish, fish oil, goaty, sweaty, waxy);fungal (moldy, mushroom); other aromatics (fermented fruity/winey, fruity, nutty, pineapple, sauerkraut, smokey, soy sauce); mouthfeelings (astringent, biting, pungent, sharp); and fundamental tastes (sweet, sour, salty, bitter).

All attributes, except fresh fish and smokey, described significant differences among the 42 cheeses. Some of the flavor attributes, including many of the dairy attributes, the fundamental tastes, and sharp and astringent mouthfeelings, were common to all the cheeses tested in this study. Other attributes, such as buttery and butyric acid, were found in most cheeses. Several attributes, for example, cooked milk and sweaty, were specific to only a few cheeses.

The factor analysis of the data was unclear, indicating that no one factor solution best described the data. Further study of the factors indicated that groupings of some attributes resulted in substantial loss of cheese description. Therefore, the original attributes probably cannot be reduced substantially in number and still adequately describe natural cheese flavor.
A STUDY OF TEXTURE‐FLAVOR INTERACTIONS USING FREE‐CHOICE PROFILING
Authors: JAIME ISABEL , MELA DAVID J. , BRATCHELL NICK
Published: May 2007

Interactions between perceptions of texture and volatile flavors were assessed by free‐choice profiling using gelatin desserts as a model product. Gels were prepared with all combinations of 2 levels of gelatin, and 2 concentrations of 2 different flavors. A trained sensory panel profiled each sample for aroma, flavor, and oral and manual texture. Generalized Procrustes Analysis was carried out separately for each sensory modality. The results indicate that while gelatin concentration and flavor type both modified perception of flavor, flavor concentration did not. Gelatin content influenced instrumental, oral, and manual evaluations of texture; however, the type and level of flavoring had little influence on oral perception of texture.
EFFECT OF QUESTIONNAIRE DESIGN AND THE NUMBER OF SAMPLES TASTED ON HEDONIC RATINGS1
Authors: VICKERS ZATA M. , CHRISTENSEN CAROL M. , FAHRENHOLTZ STEVEN K. , GENGLER IRENE M.
Published: May 2007

A total of 450 consumers participated in a test to determine whether questionnaire length, presence of key diagnostic questions or serving position affected their hedonic discrimination among yellow cakes. Consumers evaluated four yellow cakes representing a 2 × 2 factorial design of texture and flavor flaws. They used one of the following six questionnaires: only a 9‐point hedonic scale, a 9‐point hedonic scale with open end questions, and four others comprising a 2 × 2 factorial design with two levels of questionnaire length and two levels of questionnaire completeness. Neither the presence of key attribute questions nor the length of the questionnaire affected the value or the sensitivity of the judges’ overall liking scores. Samples tasted first received higher hedonic scores than those same samples tasted second throughfifth. Judges could discriminate among the samples on the basis of overall liking best when samples were tasted fourth or fifth.