bluuebunny/crossref_metadata_2025 huggingface dataset:
HEMOGLOBIN AS A CAPTURE AGENT FOR LIPOPOLYSACCHARIDE ANTIGENS IN THE ENZYME IMMUNOASSAY OF GRAM NEGATIVE BACTERIA
Authors: BLAIS BURTON W. , OUDIT DENISE , PIETRZAK EWA
Published: May 2007

Abstract The affinity of hemoglobin for lipopolysaccharides (LPS) was exploited in its use as an inexpensive capture agent for LPS antigens in the enzyme immunoassay (EIA) of Gram negative bacteria. Two EIA formats were examined. In one, the macroporous solid phase PolymacronTM coated with hemoglobin was used to capture cholate‐heat extracted LPS antigens from broth cultures of representative Gram negative bacteria, including different Salmonella serotypes, which were then detected immunoenzymatically using specific antibodies. This provided a rapid, simple and inexpensive dot blot assay for these bacteria which minimized the requirement for laboratory equipment. In another format, a microtiter plate EIA was developed in which cholate‐heat extracted Salmonella. LPS antigens were captured in hemoglobin‐coated wells. The microtiter plate format is automatable and will therefore be useful in laboratories with high sample throughputs. While most of the results reported here focus on the detection of Salmonella spp., we also demonstrate the applicability of this system in the assay of Escherichia coli O157 LPS antigens.
OPTIMIZATION OF THE ENUMERATION OF TOTAL AEROBIC BACTERIAL FLORA IN THE FLESH OF SEAFISH
Authors: VALLÉ M. , EB P. , TAILLIEZ R. , MALLE P.
Published: May 2007

Abstract The total aerobic flora of seafish flesh is weakly halophilic, and requires on average 1.38% NaCl according to statistical studies. Enumeration is optimal on tryptone soya agar or on NaCl supplemented plate count agar (‐H2S), incubated at 20 and 25C, respectively. Plate count agar (‐H2S) was selected because it can also be used for enumeration of hydrogen sulfide‐producing bacteria by degradation of sulfur‐containing proteins, which are abundant in fish The models employed are sigmoidal. The initial bioburden is too great for there to be a lag phase during storage in ice at 0C. The models show that when the total aerobic microflora count exceeds 100,000 cfu/g, whole or filleted fish stored on ice at 0C are unfit for consumption.
NEW METHODS FOR SCREENING LACTIC ACID BACTERIA THAT PRODUCE BACTERIOCIN ACTIVE AGAINST LISTERIA MONOCYTOGENES AND FOR DETERMINING BACTERIOCIN ACTIVITY 1
Authors: KANG DONGHYUN , FUNG DANIEL Y.C.
Published: May 2007

Abstract New methods using a microtiter plate for screening lactic acid bacteria (LAB) that produce bacteriocin active against Listera monocytogenes, and determination of bacteriocin activity using Omnispec 4000 were developed. In Modified Oxford (MOX, Oxoid) medium, L. monocytogenes produces a black color around the growth. In this study, inhibition of L. monocytogenes by bacteriocin was determined using the color change of the medium in a microtiter plate. Because each well of a microtiter plate limits the spread of microbial growth activity, this method can overcome the disadvantage of the agar overlay method in which a large clear zone can cover other microorganisms that are not producing bacteriocin. This new method is rapid, simple, and economical. Among the 96 strains of LAB isolated from meat, 25 strains produced bacteriocin against L. monocytogenes. The Omnispec 4000 was used to automatically record color changes due to the growth of L. monocytogenes in MOX medium containing six different concentrations of Nisin (bacteriocin) in wells of a microtiter plate. Depending on bacteriocin activities (IU). the slopes of the color changes recorded were different. The bacteriocin activities were determined easily and accurately by using the slopes to construct a calibration curve (r2= 0.96).
COMPARISON OF KANG‐FUNG MEDIUM AND MRS MEDIUM FOR SCREENING PEDIOCOCCUS SPP. FROM MIXED CULTURE SYSTEMS 1
Authors: KANG DONGHYUN , FUNG DANIEL Y.C.
Published: May 2007

Kang‐Fung medium was developed for recovering Pediococcus spp. from mixed culture systems. This medium contains phenylethanol (1.75%) with MRS agar ingredients. Many nonlactic acid bacteria can grow on MRS medium regardless of aerobic or anaerobic conditions. In comparison with MRS medium, Kang‐Fung medium was not significantly different (P > 0.05) for recovering Pediococcus spp. However, the Kang‐Fung medium completely inhibited the growth of several foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus) that can grow on MRS medium. Therefore, this medium can be used to selectively recover Pediococcus spp. from fermented food products mixed with these foodborne pathogens.
BACTERIA COLONY IDENTIFICATION USING VIDEO IMAGING
Authors: LE MOAL G. W. , LERAY P. , ROUDOT A.‐C. , THOUVENOT D. , VASSEUR V.
Published: May 2007

This paper describes an image analysis method to detect and locate Salmonella colonies grown on Petri dishes, on two different media. The colonies are described using their common feature characteristics: black center surrounded by a clear halation. Morphological image analysis functions are preferred to gray levels because of the color inhomogeneity of the background even under optimal lighting. The results obtained show the good ability of this method for detecting and locating but further work is needed to validate it on a greater number of Petri dishes.
SUITABILITY OF SELECTIVE MEDIA FOR RECOVERY OF HEAT‐STRESSED ESCHERICHIA COLI O157:H7
Authors: FISHER TOMEKA L. , GOLDEN DAVID A.
Published: May 2007

Tryptone soya agar (TSA) and three selective media, BCM1M O157:H7(+) agar (BCM), modified eosin methylene blue agar (MEMB), and sorbitol MacConkey agar (SMAC) were evaluated for recovery of two strains of E. coli O157:H7 (salami and cider isolates) heated at 56, 58, and 60C for up to 60 min in tryptone soya broth (TSB). TSA and MEMB were equally effective at recovery of heat‐stressed (56, 58, and 60C) E. coli O 157:H7 and superior to SMAC and BCM (P 0.05). When heated at 56 and 58C, recovery of E. coli O157:H7 on MEMB and TSA was not significantly different (P > 0.05); recovery was poorer on SMAC, followed by BCM (P 0.05). There was no significant difference in recovery of E. coli O157:H7 on BCM and SMAC when strains were heated at 60C (P > 0.05).
ESCHERICHIA COLI O157:H7 AND FERMENTED SAUSAGES: A REVIEW1
Authors: GETTY KELLY J.K. , PHEBUS RANDALL K. , MARSDEN JAMES L. , FUNG DANIEL Y.C. , KASTNER CURTIS L.
Published: May 2007

Escherichia coli O157:H7 emerged as a foodborne pathogen in 1982 and can cause three major disease syndromes (hemorrhagic colitis, hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura). Outbreaks caused by E. coli O157:H7 have been linked to ground beef, milk, apple cider, lettuce, radish and alfalfa sprouts, and water. In 1994, an outbreak of E. coli O157:H7 infection was linked to dry, fermented, pork and beef salami. In response to this first implication of a dry fermented sausage product, the United States Department of Agriculture/Food Safety Inspection Service developed guidelines requiring sausage manufacturers to validate that their processes achieve a five‐log reduction of E. coli O157:H7. Various validation studies have shown that E. coli O157:H7 is able to survive in sausages that are fermented and then dried to various moisture‐to‐protein ratios of 2.3, 1.9, or 1.6:1. Additional thermal processing methods or longer fermentation processes were utilized to achieve 5‐log reductions.
HIGH PRESSURE PROCESSING FOR FOOD SAFETY AND PRESERVATION: A REVIEW1
Authors: YUSTE JOSEP , CAPELLAS MARTA , PLA REYES , FUNG DANIEL Y.C. , MOR‐MUR MONTSERRAT
Published: May 2007

High pressure processing is the technology by which a product is treated at or above 100 MPa. Pressure is transmitted uniformly and instantaneously throughout the food, which allows very homogeneous products to be obtained. Pressurization does not change the nutrient content, odor, and taste. The food structure by itself probably performs a baroprotective effect and so the rate of surviving microorganisms increases. It is likely that modifications in cytoplasmic membrane (the primary site of pressure damage) are the main cause of sublethal injury generated by pressure treatment to some microorganisms. High pressure processing effectively inactivates the spoilage microbiota of several foods, and important foodborne pathogens such as Campylobacter jejuni, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. Foods can be pasteurized at low or moderate temperatures under pressure. Pressurization at high temperature can sterilize foods. Pressure treatment is of special interest for products or meals containing ingredients that are extensively modified by heat.
APPLICATIONS OF TIME‐RESOLVED FLUOROIMMUNOASSAY TO DETECT MAGNETIC BEAD CAPTURED ESCHERICHIA COLI O157:H7
Authors: TU SHU‐I , GOLDEN MARSHA , ANDREOTTI PETER , YU LINDA S.L. , IRWIN PETER
Published: May 2007

A time‐resolved fluorescence technique was developed to detect Escherichia coli O157:H7 in ground beef burger. After a 4.5 h enrichment period, streptavidin coated magnetic beads conjugated with biotin‐labeled anti E. coli O157:H7 were used to capture the bacteria. The bacteria were, at the same time, also labeled by a nonfluorescent, europium (Eu)‐tagged anti‐E. coli O157:H7 antibody. The sandwiched bacterial complexes were then concentrated using a magnetic particle concentrator and washed to remove other solution components. Upon addition of an enhancement buffer, the Eu‐labels were then released from the antibodies and chelated to nitrilo‐triacetic acid (NTA) and trioctylphosphine oxide (TOPO) to form highly fluorescent Eu‐(2‐NTA)3(TOPO)2–3 micellar complexes. Delayed fluorescence associated with these complexes was measured and its intensity was used to estimate the original bacterial concentration spiked in hamburger. This approach was applied to detect E. coli O157:H7 spiked in hamburgers. The results indicated this method is able to detect 1 CFU/g of the bacteria after a brief enrichment for four and half hours at 37C. Specificity studies indicated that the approach exhibited no or limited cross reactivity to Salmonella typhimurium, E. coli K‐12 or Shigella dysenteriae spiked in hamburgers. Thus, the developed approach may be used as a rapid screening procedure for E. coli O157 bacteria in foods.
ACCELERATION OF BUTTERMILK FERMENTATION BY BACTERIAL MEMBRANE FRACTION BIOCATALYSTS1
Authors: TUITEMWONG K. , FUNG D.Y.C. , TUITEMWONG P. , HOFFMANS C.M.
Published: May 2007

Efficacy of the bacterial membrane fractions to hasten the buttermilk fermentation was evaluated. Membrane fraction biocatalysts, at 0.1–2.0 U/mL, obtained from Escherichia coli (E‐8), Gluconobacter oxydans (Gox), and Acetobacter xylinum (Acx) and a “OxyraseTM” effectively stimulated cell growth of buttermilk cultures (Lactococcus lactis, L. cremoris, and Leuconostoc spp.) and lactic acid production of the buttermilk fermentation. The membrane fractions scavenged oxygen in the fermenting milk to provide an optimal oxygen tension for growth of the cultures. OxyraseTM and E‐8 membrane fractions significantly increased the rate of pH reduction by stimulating lactic acid production to reach the desirable conditions (pH 4.8 and 0.85% acidity as lactic acid) by 0.4–3.5h and 0.9–3.3h, respectively, depending on the concentrations, which was faster than the controls. Gox and Acx, at 0.1–1.0 U/mL stimulated the production to finish 1.5 to 2.5h faster than that of the control. Each membrane fraction biocatalyst depleted dissolved oxygen in the buttermilk mix differently. Total counts of the cultures with OxyraseTM and E‐8 membrane fractions at 0.5 U/mL were significantly higher than those of the control by 0.5–1.0 log cycle during hours 3–7.
IMPORTANCE OF REFERENCE STANDARDS IN TRAINING PANELISTS
Authors: RAINEY BARBARA A.
Published: May 2007

When training a sensory evaluation panel, reference standards play an important role in developing appropriate terminology, establishing intensity ranges and showing the action of an ingredient. In addition, use of reference standards reduces the amount of training time while providing documentation for terminology. Product characteristics can be demonstrated through reference standards for application in plant quality assurance programs as well as for project planning in new product development, product maintenance (i.e., shelf‐life), product improvement and cost reduction programs.
SOME SOURCES OF BIAS IN CONSUMER TESTING
Authors: GACULA M.C. , RUTENBECK S.K. , CAMPBELL J.F. , GIOVANNI M.E. , GARDZE C.A. , II R.W. WASHAM
Published: May 2007

Data sets from three studies were examined to determine the effects of brand identification and package design on consumer responses during product evaluation. In these studies, consumers evaluated products with or without brand identification, compared products in standardized conditions, and compared products in different package designs with different or identical product contents. Measurement of consumer responses for all studies was based on 9‐point hedonic scale. The results of the study showed that consumers were less critical in their evaluation when the samples being assessed were identified by brand names. Brand identification and package design, when not concealed in the comparison of product contents, resulted in consumer response bias. Also, the popularity of a brand influenced consumer's perception of products.
THE IMPORTANCE OF LANGUAGE IN DESCRIBING PERCEPTIONS
Authors: CIVILLE GAIL VANCE , LAWLESS HARRY T.
Published: May 2007

A set of terms in descriptive analysis should enable differentiation among products, specification of the sensory properties of the products, and sufficient characterization to permit its recognition or identification. Meeting these criteria enables the use of descriptive data in several applications: (1) interpretation of other sensory data, (2) correlation with instrumental measures, (3) quality monitoring, and (4) product development and maintenance. Several aspects of the specific terminology and the way it is taught are important in effective descriptive analysis. Terms should be uncorrelated with one another. Terms should be related to physical or chemical references. Training a panel requires the establishment of a system in which relevant dimensions can be abstracted and attended to. In this paper, specific problems of descriptive analysis training such as the choice of reference sets and the boundaries of terms are discussed.
SENSORY INTERACTIONS IN MIXTURES
Authors: LAWLESS HARRY T.
Published: May 2007

Psychological studies have assessed the intensity of simple sensory mixtures, both in taste and olfaction. In taste mixtures, suppression or partial masking among the components is often observed. An analogous result is often found in odor mixtures, counteraction of one component in the presence of a second odor. These effects, particularly taste suppression, are also observed in food systems. Interactions between sensory modalities are far more complex, ranging from inhibition of taste and odor sensations by trigeminal irritation, to relative independence of tastes from odor stimulation and independence of odors from tastes.
USE OF INDIVIDUAL DIFFERENCES SCALING FOR SENSORY STUDIES: SIMULATED RECOVERY OF STRUCTURE UNDER VARIOUS MISSING VALUE RATES AND ERROR LEVELS
Authors: WHELEHAN O.P. , MACFIE H.J.H. , BAUST N.G.
Published: May 2007

The use of Individual Differences Scaling in sensory studies has been limited because the number of pairwise comparisons in a complete design can be prohibitively large. This study examines the effect of different levels of error and missing data on recovery of true structure by Individual Difference Scaling for the normal range of assessors and stimuli (8–16) used by sensory workers. Recovery was very good for a missing value rate of 20%. It was good for 40% provided that the number of stimuli was high, but deteriorated sharply at 60% missing data. The effect of superimposing random error on to the true structure indicated that a large error rate gave poor recovery. It is concluded that up to 40% of the distances in a complete design could be excluded, provided that replicate measurements indicated error levels were not severe.
EFFECT OF SAMPLE NUMBERS ON THE SENSORY ACUITY OF A TRAINED GROUND BEEF TEXTURE PANEL
Authors: BOHNENKAMP J.S. , BERRY B.W.
Published: May 2007

Trained sensory panelists evaluated 8,12 or 18 samples of ground beef at each meeting to determine the effect of sample numbers on panelist perception of certain sensory properties. Six ground beef formulations were selected to represent a broad range of fat and connective tissue content. Panelists evaluated samples for tenderness, connective tissue amount and juiciness. Sensory ratings were affected by formulation, anticipation of sample numbers and actual number of samples (sample x session). Although panelists discriminated among formulations presented in the last six samples somewhat differently from the way they discriminated among the same formulations presented in the first six samples, there was little evidence that the panel became less sensitive.
IMPLEMENTATION OF CONSUMER TASTE PANELS
Authors: NALLY CAROL L.
Published: May 2007

A taste panel consisting of residents from the local community was developed. In this paper, the benefits of a consumer panel over an in‐house panel are discussed. Recruitment procedures, panelist training and performance monitoring are outlined.
THE PSYCHOPHYSICAL RELATIONSHIP BETWEEN COLOR AND SALT CONCENTRATIONS IN CHICKEN FLAVORED BROTHS
Authors: GIFFORD SANDRA R. , CLYDESDALE FERGUS M. , DAMON RICHARD A.
Published: May 2007

Taste panelists evaluated the effect of color on salt perception in chicken flavored samples using magnitude estimation. Samples were colored to simulate commercial chicken broth. Five color intensities were added to 5 NaCl concentrations ranging from 0.34 to 0.66% (w/v). Color had no influence on salt perception. Panelists were able to perceive color differences among samples (P <0.001) and these were correlated with the objective color function cot−1 (a/b) calculated from the L,a,b values obtained from the Gardner XL‐23. Overall flavor preference was evaluated by a taste panel using the technique of magnitude estimation. NaCl concentrations ranged from 0.52 to 0.80% (w/v). Overall flavor preference was unaffected by color. A reduction in NaCl concentration from 0.80% (w/v) to 0.52% (a 35% reduction) did not alter flavor preference. A 50 member consumer panel using a paired comparison test found no difference in flavor preference between an uncolored sample containing 0.80% (w/v) NaCl and a colored sample containing 0.72% (w/v) NaCl.
DEVELOPMENT OF A LEXICON FOR THE DESCRIPTION OF PEANUT FLAVOR
Authors: JOHNSEN PETER B. , CIVILLE GAIL VANCE. , VERCELLOTTI JOHN R. , SANDERS TIMOTHY H. , DUS CLARE A.
Published: May 2007

A lexicon of terms to describe desirable as well as undesirable flavors in peanuts has been developed. The lexicon and an intensity rating scale was developed by a 13 member panel of flavor and peanut specialists representing industry and the USDA‐Agricultural Research Service. This system is intended to provide definitive, common terminology for use in communicating differences in peanut flavor variables among all phases of peanut research and industry.
APPLICATIONS OF SENSORY SCIENCE WITHIN THE TOBACCO INDUSTRY
Authors: JELTEMA MELISSA A. , TINDALL JOHN E. , SOUTHWICK EVERETT W.
Published: May 2007

Sensory testing of cigarette smoke presents some unique problems to the sensory specialist. This is due to a variety of reasons including the high degree of similarity between blended cigarettes and a high degree of variability between individual cigarettes. In the cigarette industry, a large effort has been placed on adapting and developing new methods of collecting and analyzing sensory‐data on both flavorants and cigarette smoke. These methods include odor profiling and multidimensional scaling based on attributes and acceptability scales. In addition, extensive research has been conducted to determine the number of relevent dimensions to smoking and the types of changes that could affect consumer acceptance or purchase behavior.
ACADEMIC VS. INDUSTRIAL PERSPECTIVES ON SENSORY EVALUATION
Authors: LAWLESS HARRY T. , KLEIN BARBARA P.
Published: May 2007

The current practice of sensory evaluation occurs in two general settings: the academic environment of a university laboratory and within the foods and consumer products industries. Sensory evaluation programs can differ in orientation, objectives, methodology and context, and viewed from the perspective of Brinberg's tripartite validity theory, focusing on experimental, theoretical and empirical paths. Differences in organizational goals and resources between academia and industry result in different uses of panels, statistics and collaborative efforts. Opportunities for advancement of the field of sensory science exist within the framework of academic training of and industrial demand for sensory professionals.
TIME‐INTENSITY SCALING WITH JUDGES TRAINED TO USE A CALIBRATED SCALE: ADAPTATION, SALTY AND UMAMI TASTES
Authors: O'MAHONY MICHAEL. , WONG SAU‐YIN.
Published: May 2007

The Time‐Intensity scaling technique was modified for measurements of taste intensity. Instead of using the traditional procedure where intensities were estimated on the judges’ own internalized scales, judges were trained to estimate concentrations directly in millimolar concentration. Such training was seen to increase precision, although the general shapes of the Time‐Intensity plots remained the same. The technique was applied to measurement of taste intensity change over time when NaCl or MSG stimuli were held in the mouth. Using this technique, it was possible to measure the relative effects, on taste intensity loss, of stimulus dilution by saliva and sensory adaptation; the latter had the greater effect. Accordingly, the disruption of adaptation was found to be more important than increased salivation when chewing movements were made.
SINGLE‐POINT VERSUS TIME‐INTENSITY SENSORY MEASUREMENTS: AN INFORMATIONAL ENTROPY ANALYSIS1
Authors: LEE III WILLIAM E.
Published: May 2007

Single‐point sensory response measurement techniques such as magnitude estimation and category scaling only contain a limited amount of information. Time‐intensity (T‐I) data collection techniques provide much more information, addressing rate‐related and duration aspects as well as intensity quantification. A theoretical analysis and comparison of single‐point and T‐I responses is presented from an informational (Shannon) entropy content viewpoint. The analysis is based on a hypothetical T‐I response curve and a hypothetical series of single‐point measurements attempting to approximate the T‐I curve. Assuming a 15 s sensory event the associated T‐I response of a single parameter is shown to contain a significantly greater amount of potential information storage capacity relative to the single‐point or a small series of single‐point measurements attempting to generate temporal behavior. Theoretically, the T‐I response also displays greater quantities of a parameter called information density. Finally, it may be hypothesized that T‐I techniques can be shown to be more efficient in terms of rate of information acquisition.
QUALITY OF POWDERED BLACK PEPPER (PIPER NIGRUM L.) DURING STORAGE. I. SENSORY AND PHYSICOCHEMICAL ANALYSES
Authors: NARASIMHAN SHANTHI. , CHAND NAGIN. , RAJALAKSHMI D. , INDIRAMMA A. R.
Published: May 2007

Black pepper powder (60 mesh) was stored in consumer unit packs of 100g capacity in low density polyethylene (LDPE) films of 100, 300, and 500 gauge at 27°C and 65% RH. Analyses for sensory quality (odor and flavor), volatile oil, oleoresin, piperine content, and TLC were carried out at 15, 30, 45 and 80 days of storage. Significant loss of “top notes”, volatile oil, and hydrocarbons were seen after 15 days of storage itself while the “basic notes” and oxygenated compounds were retained up to 45 days. There was no loss of piperine up to the end of the study. The black pepper powder was not fit for table use after 15 days, though it could be used for other culinary purposes up to 80 days of storage.
OPTIMIZATION OF PROCESSING OF PEANUT BEVERAGE1
Authors: GALVEZ FLOR CRISANTA F. , RESURRECCION ANNA V. A. , KOEHLER PHILIP E.
Published: May 2007

Peanut beverages were prepared and homogenized at 2000, 4000, and 6000 psi and processed at 100°C for 10, 15, and 20 min and at 121°C for 5, 10, and 15 min. Sensory analysis, gas chromatographic (GC) analysis, and viscosity measurements were performed on the products. Sulfur aromatic was found sufficient to discriminate between samples processed at 100°C whereas sulfur aromatic, cooked peanut flavor, and bitterness provided the most efficient combination for discriminating between samples processed at 121°C. Processing time had a more significant effect on the sensory attributes of products. Optimum conditions for processing were found to be at homogenization pressure > 3100 psi and process time > 16 min at a processing temperature of 100°C. No sensory characteristic of the peanut beverage correlated with the instrumental analyses done.
EVALUATION OF PANELIST PERFORMANCE IN DESCRIPTIVE PROFILING OF RANCID SAUSAGES: A MULTIVARIATE STUDY
Authors: SINESIO FIORELLA. , RISVIK EINAR. , RØDBOTTEN MARIT.
Published: May 2007

This paper illustrates an application of principal component analysis (PCA), partial least squares regression (PLS) and generalized procrustes analysis (GPA) to evaluate the ability of a trained group of assessors to perceive rancidity in foods.

PCA and regression PLS were utilized to determine to which extent sensory attributes capture the information perceived by a trained sensory panel, and if this can be developed into a predictive model for rancidity in sausages.

The data were submitted to a GPA to obtain a map of the products for each subject as compared with a consensus products map. Assessors plots for the sensory attributes were also obtained to reveal the dissimilarities between panelists and to explore clustering.
INGESTION AND EXPECTORATION SAMPLING METHODS OF FOUR TASTES IN A MODEL SYSTEM USING TIME‐INTENSITY EVALUATIONS
Authors: OTT DANA B. , PALMER SUZANNE J.
Published: May 2007

The objective of this investigation was to compare two sampling methods (expectoration and ingestion) of single component water solutions (sweet—5% sucrose, sour—0.006% citric acid, bitter—0.027% caffeine, salty—0.325% sodium chloride) using time‐intensity (T‐I) evaluations. Analysis of variance was used to evaluate significant differences. There were subject inconsistencies for the recording times (RT) of sucrose, caffeine and sodium chloride tastes among the sampling methods. No panel differences were found for citric acid duration (RT) between ingested or expectorated samples. Individual contradictions for amplitude sucrose and sodium chloride mixtures were apparent however, the panel demonstrated no differences among the amplitude means between the sampling methods for citric acid and caffeine solutions. Aftertastes for ingested sodium chloride solutions were significantly (P < 0.01) greater than for expectorated samples whereas sampling techniques had no effect upon caffeine aftertastes. Individual contradictions were apparent for citric acid and sucrose aftertastes between the sampling methods.
MODIFICATIONS TO SENSORY DIFFERENCE TEST PROTOCOLS: THE WARMED UP PAIRED COMPARISON, THE SINGLE STANDARD DUO‐TRIO AND THE A‐NOT A TEST MODIFIED FOR RESPONSE BIAS
Authors: THIEME URSULA. , O'MAHONY MICHAEL.
Published: May 2007

Modifications were made to difference tests on the basis of psychophysical theory and tested using a model system. The A‐not A test was modified by the addition of sureness judgements to free the test from response bias; ‘warm‐up’improved test sensitivity. Regular duo‐trio tests were modified by using the weaker stimulus as the standard, increasing test sensitivity. The paired comparison cannot be used unless the dimension of the difference can be described. However, the warm‐up procedure allows opportunity for judges to describe the difference and their own words can then be used for the test. The resulting warmed‐up paired comparison was more sensitive than any modification of the duo‐trio.
USE OF CONTRASTS FOR THE EVALUATION OF PANEL INCONSISTENCY1
Authors: LUNDAHL D. S. , McDANIEL M. R.
Published: May 2007

The panelist by treatment interaction variation is used to investigate panel inconsistency. The approach tests for panelist outliers with different univariate response patterns to a set of treatments to determine the relative effect(s) of interaction variation sources on the detection of treatment differences. Algorithms and examples are followed by a discussion of the theoretical and practical significance of panel inconsistency and the removal of panelist outliers.
EFFECT OF REPEATED INGESTION OF WATER AND SOLID SUCROSE ON THE DIFFERENTIAL SENSITIVITY TO SUCROSE AND ASPARTAME
Authors: RICHEZ C. , SAUVAGEOT F.
Published: May 2007

The differential sensitivity to sucrose or Aspartame in water was studied over the course of 90 min sessions, using a sequential method. The assessors had not eaten since 9 a.m. and the sessions began at 12 noon. Two factors were studied: water ingestion and solid sucrose ingestion every 5 min. The ingestion of water had no effect on discriminative sensitivity. However, the ingestion of solid sucrose had an effect; it maintained discriminant ability in contrast to the protocol without ingestion. The reason for this effect of sucrose is not known; it might be metabolic, hedonic or perhaps something else.
INFLUENCE OF PANEL INCONSISTENCY ON THE OUTCOME OF SENSORY EVALUATIONS FROM DESCRIPTIVE PANELS
Authors: LUNDAHL D.S. , McDANIEL M.R.
Published: May 2007

Different types of panelist by treatment interaction are explored to determine how they influence the outcomes of discrimination tests. The study compares the situations where panelists are considered as fixed or random effects over the range of most testing conditions for small panels (5–15 panelists) that replicate their judgements. Magnitude interaction and nonperceivers or nondiscriminators have minor effects on test outcomes. Cross‐over interaction increases the chances for a type II error, especially when panelists are considered as random effects. False discrimination increases the chances for a type I error when panelists are considered as fixed effects. Applications of methods to reduce the chances for these errors in the testing for differences among treatments are discussed.
EFFECT OF QUANTITY CONSUMED ON MEASURES OF LIKING FOR SALT CONCENTRATIONS IN SOUP
Authors: SHEPHERD R. , FARLEIGH C.A. , WHARF S.G.
Published: May 2007

Two studies are reported on the effect ofingestion on the relative‐to‐ideal ratings of salt in soup. In the first study there was a reduction in the measure of ideal concentration from pre‐ to post‐ingestion, with subjects consuming the soups ad libitum. However, a measure of ideal concentration derived from several small samples presented in each session agreed well with the final post‐ingestion ideal. A measure of most preferred concentration of salt based on total soup consumption was unrelated to the other measures.

In the second experiment, the post‐ingestion decrease in most preferred salt concentration was replicated when subjects consumed a fixed quantity of soup. The post‐ingestion ideal was similar to that derived from rating either several small samples in one session or one single small sample per session.
USE OF THE RECEIVER OPERATING CHARACTERISTIC IN THE STUDY OF TASTE PERCEPTION
Authors: IRWIN R. JOHN , HAUTUS MICHAEL J. , STILLMAN JENNIFER A.
Published: May 2007

Studies of the Receiver Operating Characteristic (ROC) for taste are reviewed and new data on its shape are presented. What evidence there is suggests that ROCs for taste conform to the normal‐normal equal variance model of signal detection theory. Few ROCs for taste have been reported, probably because the large number of trials required by detection theory makes the task arduous for subjects in taste experiments. However, pooling ratings from several subjects and estimating the parameters of the pooled ROC by jackknife techniques circumvents that problem to some extent. Because experiments on taste are often based on a small number of trials, it is especially useful to determine the standard errors of ROC parameters. Methods for estimating these standard errors, including that of the area measure, p(A), are therefore presented.
RELIABILITY OF THE FOCUS GROUP TECHNIQUE IN DETERMINING THE QUALITY CHARACTERISTICS OF MUNGBEAN [VIGNA RADIATA (L.) WILCZEC] NOODLES
Authors: GALVEZ FLOR CRISANTA F. , RESURRECCION ANNA V.A.
Published: May 2007

Two commercial samples were evaluated in five focus group sessions to determine the reliability of the focus group technique in identifying the desirable and important sensory characteristics of dry and cooked mungbean noodles and to determine its quality characteristics. Each focus group consistently identified a similar list of desirable and undesirable characteristics. These results indicated that the focus group technique was a reliable method for determining consumer criteria for quality for mungbean noodles. When there is a need to determine consumers’ definition of product quality at a stage when consumer testing is not desired, the focus group technique can be used as a valuable tool. Mungbean noodle quality was found to have two distinct aspects: appearance of the dry noodles and eating quality of the cooked noodles. Color, glossiness, and transparency are the most important characteristics of dry starch noodles while mouthfeel or texture is considered the most important characteristic of cooked starch noodles. Color, taste, and odor of the cooked noodles were considered not as important.
SENSORY DIFFERENCE TESTING: RANKING R‐INDICES ARE GREATER THAN RATING R‐INDICES
Authors: ISHII R. , VIE A. , O'MAHONY M.
Published: May 2007

R‐index measures obtained by rating and by ranking were compared using a model system. Tne prediction that R‐indices obtained by ranking should exceed values obtained by rating was confirmed for both ranking computations: RJB and RMAT‐
A COMPARISON OF FREE‐CHOICE PROFILING AND THE REPERTORY GRID METHOD IN THE FLAVOR PROFILING OF CIDER
Authors: PIGGOTT J.R. , WATSON M.P.
Published: May 2007

Free‐choice profiling has been used to collect descriptive sensory data from both trained and untrained assessors, though untrained assessors may have difficulty in generating sufficient and adequate descriptors. The more structured repertory grid method has been used as an alternative procedure, and is thought to help assessors in vocabulary development. To compare these two procedures, panels of assessors used them to describe the sensory properties of 25 ciders. Generalized Procrustes analyses of the two data sets provided broadly similar results, but the repertory grid method yielded more descriptors and interpretation of the resulting product space was slightly easier. However, the repertory grid method took slightly longer to carry out, and it was concluded that neither method was clearly superior.
A RESEARCH NOTE: USE OF A SIGNAL DETECTION RANKING ANALYSIS TO MEASURE PREFERENCE FOR COMMERCIAL AND ‘HEALTH MODIFIED’ CAKES
Authors: CHAUHAN J. , O'MAHONY M.
Published: May 2007

Consumer preference for a common ‘yellow cake’ prepared from a commercially available cake mix and for three ‘health modified'cakes was measured using signal detection ranking procedures. Consumers found the ranking protocol simple to use, making it a viable alternative to hedonic scaling. Measures of likelihood to choose to eat, after provision of nutritional information about the cakes, showed the same trend as measures of preference taken before. Yet, the dominance of preference for yellow cake over the ‘health modified’ cakes was reduced.
EFFECTS OF TESTING EXPERIENCE ON PERFORMANCE OF TRAINED SENSORY PANELISTS1
Authors: IV EDGAR CHAMBERS , SMITH ELIZABETH A.
Published: May 2007

Data from an inexperienced and experienced sensory panel with similar training were compared in two experiments, the first on a product class that the experienced panel had tested extensively and the second on a product class unfamiliar to either panel. This study indicates that inexperienced panelists having the same intensive descriptive training as their experienced counterparts can be used on the same panels as experienced testers with little effect on the data. The minimal experience effect found in both experiments in this study was not the result of experience in a specific product category, but appeared to be a more general effect. We hypothesize that thorough training may be more important than experience for increased “reproducibility” in panelists.
SOME UNRESOLVED ISSUES OF CONTROL IN CONSUMER TESTS: THE EFFECTS OF EXPECTED MONETARY REWARD AND HUNGER
Authors: BELL RICK
Published: May 2007

Consumer test subjects were split into four groups: (1) Rewarded — told they would receive payment; (2) Unrewarded — told they would not receive payment; (3) Hungry — told not to eat before the test; and (4) Pre‐fed — told to eat a meal before the test. Hedonic responses for four breaded fish samples were collected. The test design was then repeated using microwave popcorn as stimuli. Rewarded subjects and hungry subjects rated samples higher than did either the unrewarded subjects or the pre‐fed subjects. The responses of both the rewarded and the hungry subjects indicated no hedonic differences between samples; but among the unrewarded and the pre‐fed subjects, significant differences between samples were found. Results present a dilemma for those experimenters using acceptance ratings by consumers to guide product development. This paper discusses the issue of whether these, and other unresolved factors, need to be controlled when conducting consumer tests.
GRAPES: A METHOD AND A SAS® PROGRAM FOR GRAPHICAL REPRESENTATIONS OF ASSESSOR PERFORMANCES
Authors: SCHLICH PASCAL
Published: May 2007

GRAPES computes individual and global analyses of variance for sensory profiling data, consisting of several sessions in which all the panelists gave scores to all the products for a number of attributes. The fitted model takes into account the session effect. GRAPES summarizes the results by means of graphical assessor scatterplots which allow to check and to compare panelist performances, such as the way of using scale, the reliability, the discrimination power and the agreement with the panel. In addition, GRAPES detects the outliers for each of these criterion. The usefulness of GRAPES for the panel leader will be demonstrated using texture and flavor profiling of 4 restructured steaks by 12 assessors for 15 attributes. The SAS® program GRAPES, available by e‐mail from the author, requires the SAS/BASE®, SAS/STAT®, SAS/GRAPH® and SAS/IML® softwares.
COMPUTERIZED PANEL TRAINING: EFFECTS OF USING GRAPHIC FEEDBACK ON SCALE USAGE
Authors: KUESTEN C.L. , McLELLAN M.R. , ALTMAN N.
Published: May 2007

A well‐trained panel is a valuable tool for describing and quantifying characteristics of a food product. This research was undertaken to study the effects of feedback during panel training. A computerized system was designed using the Macintosh computer to gather data and provide panelists with individualized instruction and immediate graphic feedback. Two levels of feedback (with or without) were delivered to the panelists over a 2‐week training period. Feedback consisted of correct response for discrimination testing and a graph displaying means and deviations for scaled data.

Results showed an expansion in the use of the line scale and an increase in precision across trials. No notable change in magnitude estimation sample scores was observed across feedback conditions; however, deviations were lower following feedback. Although exposure/practice alone provided similar changes, further differences were affected with graphic feedback. Results suggested individualized computer assisted instruction with graphic feedback may provide an efficient and effective tool to complement existing panel training techniques.
EFFICIENCY OF A CYCLIC DESIGN AND A MULTIDIMENSIONAL SCALING SENSORY ANALYSIS TECHNIQUE IN THE STUDY OF SALT TASTE
Authors: ROSETT TERRI ROBERTSON , KLEIN BARBARA P.
Published: May 2007

Multidimensional scaling (MDS) procedures produce maps of stimulus points, the dimensions of which may be sensory and/or physicochemical attributes. Our objective was to test the efficiencies of a cyclic design and a MDS method in the study of saltiness perception. Two levels of NaCl (0.1% and 0.2%, w/v) were added to two nonionic and two ionic gum solutions prepared to two concentrations. Subjects scaled dissimilarities between pairs of solutions and rated each sample for flavor attributes. Solution pairs were selected using cyclic designs. Repeated measures ANOVA determined that added NaCl was the only significant factor affecting saltiness perception. In contrast, from KYST‐2A MDS maps, we concluded that saltiness perception was influenced by gum property, gum concentration, presence of calcium and potassium, and related to binding of the sodium ion (Na+) as determined by23Na nuclear magnetic resonance (NMR) spectroscopy. The MDS cyclic design successfully reduced the number of samples and subjects when using experienced subjects.
TIME‐INTENSITY PROPERTIES OF SWEET AND BITTER STIMULI: IMPLICATIONS FOR SWEET AND BITTER TASTE CHEMORECEPTION
Authors: GUINARD JEAN‐XAVIER , HONG DOREEN Y. , BUDWIG CHRIS
Published: May 2007

Interindividual differences in sweet and bitter taste sensitivity were investigated using time‐intensity (TI) measurements and multivariate statistics. TI profiles were obtained in triplicate from 25 subjects for 23 sweet and/or bitter stimuli first matched to be approximately equi‐intense to 200 mM NaCl. Sweet stimuli, except for the larger sweeteners, were less persistent, and required less time to reach maximum intensity than bitter stimuli. The results of principal component (PCA) and cluster (CA) analyses of the stimuli X subjects matrices for maximum intensity (Imax), time to maximum intensity (Tmax), total duration (Tdur), and area under the curve (Area) suggest that sweet and bitter stimuli do not share common receptors; and that there are at least two receptor mechanisms each for sweet taste (one for sugars and other small compounds, and the other for large sweeteners) and bitter taste (one for PTC/PROP and one for other bitter compounds).
TEXTURE OF SWEET ORANGE GELS BY FREE‐CHOICE PROFILING
Authors: COSTELL E. , TRUJILLO C. , DAMASIO M.H. , DURAN L.
Published: May 2007

Texture of orange gels prepared with 15% fruit pulp, sucrose up to 55° Brix and five different gelling agents — kappa‐carrageenan, kappa‐carrageenan plus locust bean gum, alginate, gellan gum, and gellan, xanthan and locust bean gums — was studied by Free‐Choice Profile (FCP) analysis. Maximum rupture force and deformation at rupture were also determined by uniaxial compression in an Instron texturometer. Generalized Procrustes Analysis applied to FCP data permitted differentiation between samples and informed on the textural attributes responsible for the observed differences. Sensory differences were in general in accordance with mechanical differences. However, carrageenan and gellan gum gels were differentiated with the sensory method applied but not with mechanical tests.
A SYSTEMATIC APPROACH TO PREDICTION OF SNACK CHIP ACCEPTABILITY UTILIZING DISCRIMINANT FUNCTIONS BASED ON INSTRUMENTAL MEASUREMENTS
Authors: WARD CYNTHIA D.W. , RESURRECCION A.V.A. , McWATTERS K.H.
Published: May 2007

To determine quality characteristics of snack chips, six snack chip prototypes containing cowpea flour, cornmeal, wheat flour and cornstarch (26, 34, and 42%) were formulated. Desirable characteristics as determined by three focus groups were a golden yellow color in a thin, smooth corn‐chip form with crunchy or crispy texture, greaseless or dry mouthfeel and salty corn flavor. Chips were undesirable if brown‐colored, thick, oily or greasy, had either hard or crumbly texture, and had bland, fishy, or burnt flavors. In consumer acceptance tests, commercial products were found to be more appealing than the experimental products. A discriminant model based on instrumental measurements of color and texture from 11 snack chip samples (six prototypes and five commercial samples) correctly grouped 100% of the acceptable and 90% of unacceptable products.
BEER BITTERNESS DETECTION: TESTING THURSTONIAN AND SEQUENTIAL SENSITIVITY ANALYSIS MODELS FOR TRIAD AND TETRAD METHODS
Authors: MASUOKA SUSUMU , HATJOPOULOS DIMITRIOS , O'MAHONY MICHAEL
Published: May 2007

Thurstonian modeling predictions were tested and confirmed for 3‐AFC and triangle test methods, as well as for different versions of the tetrad test method, using judges who were required to discriminate bitterness in beer. Sequential Sensitivity Analysis predictions were also confirmed for 3‐AFC/triangular methods but not for the tetrad method. It is hypothesized that memory effects might have interfered with the later prediction.
CONTEXTUAL SHIFTS IN HEDONIC JUDGMENTS
Authors: SCHIFFERSTEIN HENDRIK N.J.
Published: May 2007

Taste intensity ratings are higher when many low‐intensity stimuli are presented than when many high‐intensity stimuli are presented. It is investigated whether similar contextual shifts occur for hedonic judgments.

Experiment 1 assessed the perceived pleasantness of a heterogeneous stimulus set containing either a large number of quinine (unpleasant context) or sucrose (pleasant context) solutions. In Experiment 2 subjects made hedonic judgments for a set of sucrose solutions. They were classified pre‐experimentally as ‘sweet‐likers,’‘neutrals,’ or ‘sweet‐dislikers.’ Stimulus frequency distributions were positively or negatively skewed. In Experiment 1, hedonic ratings in the pleasant context were lower than those obtained in the unpleasant context. In Experiment 2, no effect of stimulus context was found.

It is argued that contextual shifts in hedonic judgments are found only if the stimuli differ substantially along the hedonic dimension. In addition, the subject groups should be homogeneous with regard to preference rank orders, and should be sufficiently large to allow testing with adequate statistical power.
CHALLENGES OF EVALUATING SENSORY ATTRIBUTES IN THE PRESENCE OF OFF‐FLAVORS (GEOSMIN AND 2‐METHYLISOBORNEOL)
Authors: BETT K.L. , JOHNSEN PETER B.
Published: May 2007

The impact of 2‐methylisoborneol (MIB) (earthy/musty), on the flavor evaluation of farm‐raised catfish was assessed by a descriptive analysis panel, who are trained to evaluate flavor intensity using universal scales. Ideally, panelists should give the same intensity ratings for all attributes within a sample. Realistically, individual panelists perceive flavor intensity differently, because of variations in detection thresholds, adaptation, fatigue and enhancement or suppression. Experiments were designed to investigate problems associated with evaluating catfish flavor. Samples “spiked” with MIB had lower chickeny flavor than unspiked. Intensities of MIB in spiked samples that followed an equally spiked sample were lower. Problems can occur when catfish are presented at intervals less than 7 min. Panelists experienced difficulty in determining intensity differences of MIB flavor between sessions, but could determine differences in intensity of MIB within a session. These influences must be accounted for in experimental designs to assess catfish flavors.
EXPERTS VERSUS CONSUMERS: A COMPARISON
Authors: MOSKOWITZ HOWARD R.
Published: May 2007

This paper compares experts and consumers to determine the degree to which they agree with each other on ratings of 37 sauce products, using the same sensory attributes. The paper also assesses the degree to which sensory attribute ratings correlate with objective physical measures. The ratings of experts (1‐9 scale) and consumers (0–100 scale) agree quite highly, as shown by the high correlation between the two panels across the 37 products. The paper refutes the notion that consumers are incapable of validly rating the sensory aspects of products. The paper therefore presents the case for using consumers to assess the sensory characteristics of products.