bluuebunny/crossref_metadata_2025 huggingface dataset:
INSTRUMENTAL TEXTURE STUDIES ON CHOCOLATE
Authors: TSCHEUSCHNER H.‐D. , MARKOV E.
Published: February 2007

Instrumental methods to analyze texture of plain chocolates and milk chocolate are reviewed. Using a strength testing apparatus and special measuring cells a method to determine the compression strength, shear strength and rupture force during hesion testing are described. By means of a modified penetrometer equipped with a recording device the melting properties were determined. To determine the maximum value of size of disperse components a modified precision thickness testing instrument is applied. The methods offer good reproducibility. The influence of some measuring parameters and sources of error are explained.
STRUCTURAL FAILURE AND NONDESTRUCTIVE RHEOLOGICAL ANALYSES OF FRANKFURTER BATTERS: EFFECTS OF HEATING RATES AND SUGARS1, 2
Authors: SALIBA D. A. , FOEGEDING E. A. , HAMANN D. D.
Published: February 2007

The effects of heating rate and sugar type and concentration on the values of frankfurter textural parameters at structural failure were evaluated by a torsion test and a two cycle uniaxial compression test. Structural failure tests indicated that heating rate and sugar concentration had major effects on shear stress; in addition to minor effects on true shear strain. In general, heating rate had a greater effect on stresses and strains than sugar. Torsion and compression tests yielded different values, however, trends due to treatment were similar. The method used for interpretation of texture profile analysis parameters from Instron force‐deformation curves had an effect on the statistical analysis results.

A thermal scanning rheology monitor nondestructively measured rheological changes during thermal processing. During thermal processing, the major modulus of rigidity increase started at 58°C and the major decrease in energy loss occurred in the 40–60°C range. Unlike structural failure rheological properties, rigidity at 70°C was not affected by heating rate.
ANALYSIS OF FOOD CRUSHING SOUNDS DURING MASTICATION: FREQUENCY‐TIME STUDIES1
Authors: HI W. E. LEE , DEIBEL A. E. , GLEMBIN C. T. , MUNDAY E. G.
Published: February 2007

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THE MEANING OF TEXTURAL CHARCTERISTICS ‐JUICINESS IN PLANT FOODSTUFFS
Authors: SZCZESNIAK ALINA S. , ILKER REINFRIEDE
Published: February 2007

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EXTRUSION OF SORGHUM AND SORGHUM PEANUT MIXTURES: EFFECT OF BARREL TEMPERATURE AND FEED MOISTURE ON PHYSICAL‐TEXTURAL CHARACTERISTICS
Authors: PHILLIPS R. D. , FALCONE R. G.
Published: February 2007

Sorghum and 85% sorghum‐15% full‐fat peanut meals were extruded over a range of barrel temperatures (160–205°C) and feed moistures (13‐25%) in a pilot‐scale machine. The resulting products were characterized for physical and textural properties. Resulting data were fit to third order models and the corresponding response surfaces plotted. For both compositions, maximum expansion and minimum density and textural strength occurred at low‐to‐medium temperatures and moistures. Some extrudates compared favorably with commercial snack products. The addition of full‐fat peanut to sorghum meal enchanced the expansion and tenderness in the optimum range. A 70% sorghum‐30% full fat peanut mixture could not be extruded successfully.
Effects of Grind Size, Sucrose Concentration and Salt Concentration on Peanut Butter Texture 1
Authors: CRIPPEN K.L. , HAMANN D.D. , YOUNG C.T.
Published: February 2007

A 3 X 3 X 3 factorial design with three grinds (fine, medium and coarse), three salt concentrations (0, 0.6 and 1.2%) and three sucrose concentrations (0, 3 and 6%) was used in formulating peanut butters. Eleven sensory descriptive characteristics were examined, along with instrumental hardness, hesion and power law flow model constants. A consumer panel rated the peanut butter texture using a 9‐point hedonic scale. Increased grind size decreased sensory smoothness, spreadability, adhesiveness and preference ratings, but increased instrumental hesion and hardness. Increased sucrose caused decreases in instrumental hesion and hardness, sensory adhesiveness and consumer texture ratings. Added salt increased the ease of swallowing, as well as consumer preference of texture.
YIELD STRESS OF STRUCTURED AND UNSTRUCTURED FOOD SUSPENSIONS
Authors: MISSAIRE F. , QIU C‐G. , RAO M. A.
Published: February 2007

Yield stresses of 40 model suspensions of apple pulp particles with unimodal and bimodal particle size distribution in water, of 13 commercial food suspensions, and of 11 prepared apple sauce samples were determined by the vane method (s̀0V), and by application of the Casson (s̀0C) model. For the unstructured (US) apple pulp suspensions magnitudes of s̀0V and s̀0C were nearly equal, but for the structured commercial and prepared apple sauce samples, magnitudes of s̀0V were much higher than s̀0C. The ratio of s̀0V/s̀0C can be used to determine the shear diameter and the degree of structure of a suspension. Energy dissipation due to viscous drag was also higher for the structured suspensions than for the US suspensions. The results suggest that some trends observed with rheological properties of nonfood suspensions may not be applicable to structured food suspensions.
EFFECT OF WATER ACTIVITY ON CRISPNESS OF BREAKFAST CEREALS
Authors: SAUVAGEOT FRANÇOIS , BLOND GENEVIÈVE
Published: February 2007

Three breakfast cereals (two commercial products and one experimental product made by extrusion cooking) were placed over 10 saturated salt solutions in desiccators for 3 weeks and then studied by sensory and mechanical analysis. A slight decrease of sensory crispness intensity occurs between 0 and 0.50 (aw) or 7% (water content), after which there is a very rapid decrease. The value of critical water activity given by the intersection between the two straight lines which can be adjusted seems not to depend on the product. Moreover this value is confirmed by the mechanical analysis and, partially, by a Differential Scanning Calorimetry analysis. There is a good correlation between sensory crispness and deformation to the first fracture.
GELPOINT MEASUREMENTS ON HIGH‐METHOXYL PECTIN GELS BY DIFFERENT TECHNIQUES
Authors: DAHME A.
Published: February 2007

SLow steady shear deformation and small amplitude oscillation measurements have been used to characterize the onset of gelation in high‐methoxyl pectin gels. A simplified technique with a shear modulus threshold criterion is proposed for routine evaluation of the gelpoint with a normalized parameter. Limiting conditions of the three methods are discussed.
MEASUREMENT OF THE TENSILE FAILURE OF GELS
Authors: LELIEVRE JOHN , MIRZA IQBAL , TANG JUMING
Published: February 2007

Various methods of probing the tensile failure characteristics of both extensible and brittle gels using the Instron machine were evaluated. The true strain of the gels at failure determined from high speed video camera recording and the corresponding true stress were used as the reference. When the ratio of the test length to the length of the end‐pieces of a dumbbell shaped specimen exceeds 10:1, the effect of the end‐pieces was negligible and the measured stress and strain at failure by the Instron machine represent the true values in the test sector of the gel. Experimental data from tensile testing using the above method suggest that both extensive and brittle gels were weaker in tension than in compression.
CHARACTERIZATION OF THE POWER SPECTRUM OF FORCE‐DEFORMATION RELATIONSHIPS OF CRUNCHY FOODS1
Authors: ROHDE FLORIAN , NORMAND MARK D. , PELEG MICHA
Published: February 2007

The mean magnitude of the power spectra of the compressive force‐deformation relationships of breadsticks, pretzels and zwiebacks, exposed to five levels of relative humidity, was determined at various cutoff frequencies. In all three foods the mean magnitude had a linear correlation with the Fractal dimension of the normalized original force‐deformation relationship, regardless of the cutoff frequency. This implies that the jaggedness of the force‐deformation curve, which is most probably a manifestation of the material crunchiness or crumbliness, can be quantified by an additional single numerical index, the mean magnitude of the power spectrum. The correlation's independence of the cutoff frequency is an indication that the loss of crunchiness, as a result of moisture sorption, can be expressed in the shape of the whole spectrum and not only in its high frequency region.
RHEOLOGICAL BEHAVIOUR OF KAPPA‐CARRAGEENAN/GALACTOMANNAN MIXTURES AT A VERY LOW LEVEL OF KAPPA‐CARRAGEENAN
Authors: FERNANDES PAULO B. , GONÇALVES M. P. , DOUBLIER JEAN‐LOUIS
Published: February 2007

The rheological behaviour of kappa‐carrageenan/galactomannan blends, at ratios ranging from 1/99 to 5/95 in the presence of KCl, was investigated by means of viscosity and oscillatory shear measurements. These experiments were performed at 1% total polymer concentration and at 15C. The results were compared to those of the galactomannans alone (locust bean gum or guar gum).
RHEOLOGICAL AND CHEMICAL PROPERTIES OF MOZZARELLA CHEESE
Authors: YUN J. JOSEPH , HSIEH YIN LIANG , BARBANO DAVID M. , ROHN CHARLES L.
Published: February 2007

Dynamic viscoelastic parameters and chemical properties of Mozzarella cheese produced using a “no‐brine” cheese making method with 3 different cooking temperatures (38, 41, and 44C) were determined. Samples were stored for 3 weeks at 4C before dynamic mechanical analysis at 22C. G', G” and tan δ were 5.8 – 6.4 × 105 dyne/cm2, 1.9 – 2.1 × 105 dyne/cm2, and 0.33 – 0.35, respectively, at 1% strain and 10 rad/s. The percentage of intact αs‐casein and β‐casein were 38–40% and 33–35% of total protein in the cheese, respectively. The range of cooking temperatures used in this experiment had little effect on dynamic viscoelastic properties or the amount of intact protein for the cheese.
EFFECT OF UNIMODAL PARTICLE SIZE AND PULP CONTENT ON RHEOLOGICAL PROPERTIES OF TOMATO PUREE
Authors: YOO B. , RAO M.A.
Published: February 2007

The vane method in controlled shear stress mode was used to determine the yield stress and the shear rate—shear stress data of tomato purees containing 10–35% pulp of two different average particle sizes: 0.34 and 0.71 mm. Consistency index and apparent viscosity increased significantly with pulp content and decreased with average particle size. The effect of pulp weight fraction (P) on relative viscosity (ηr) could be described by the single parameter equation: ηr= [1 – (P/A)]−2, while the effect of particle diameter on ηr could be described using Peclet number. Magnitudes of yield stress determined directly by the vane method were higher than those obtained by using the Casson model, and were proportional to the square of pulp content. Reduced Casson yield stress—P data on purees of both particle sizes followd a single curve. Effects of pulp content and particle size on vane yield stress and apparent viscosity were evident from the correlation forms with high values of R2.
RELATIONSHIPS BETWEEN SENSORY VISCOSITY AND APPARENT VISCOSITY OF CORN STARCH PASTES
Authors: ZAMORA M. C.
Published: February 2007

Sensory viscosity and apparent viscosity of corn starch pastes were studied at 15°, 25°, 37° and 50C, within the concentration range 0.9%–6.2%. The oral and visual sensory viscosity estimations were obtained by the converging limits method, a modified version of magnitude estimation. The exponents (perceptual growth rate) were similar (0.40 oral and 0.41 visual). No significant differences were detected between the two evaluations. Visual stimulation yielded results with a lower deviation, suggesting that this type of judgment is easier for the subject. The consistency of results obtained by the converging limits was determined by comparison of the viscosity of starch pastes with silicone oil by cross‐modality matching. The ratio upper/lower limit of physical range used (13/0.03 for corn starch ∼ 1100/1.80 for silicone oil) is approximately the same for both substances. This is also shown by the fact that the slope of the log‐log function relating them equals 1.11 ± 0.21. No significant effect of temperature was observed on the oral viscosity estimates. The effective range of sensory viscosity for corn starch pastes was between 340 and 1300 cP.
RHEOLOGICAL CHARACTERIZATION OF BUTTER USING LUBRICATED SQUEEZING FLOW
Authors: SHUKLA A. , RIZVI S.S.H. , BARTSCH J.A.
Published: February 2007

Rheological characteristics of butters made from anhydrous milk fat (AMF) and supercritically fractionated high melting triglyceride (HMT) fraction were compared. An Instron Universal Testing Machine was used to compress the samples between two lubricated plates at constant deformation rate (0.5 mm/min). Stress growth coefficients, computed from the ratios of stresses and biaxial strain rates, were plotted as function of time. HMT butter had higher stress growth coefficients than AMF butter, indicating its greater degree of firmness. Stress growth coefficients were negatively correlated to temperature due to lower crystallinity of fat at higher temperatures and increased on storage due to formation of weak van der Waal forces of attraction between crystalline fat chains.
RHEOLOGICAL AND SENSORY CHARACTERIZATION OF VISCOUS AND PASTY FOOD PRODUCTS: APPLICATION OF FRACTAL CONCEPTS AND FOURIER ANALYSIS
Authors: MAURER K. , HARDY J.
Published: February 2007

The jaggedness of the force‐time relationship of capillary extrusion profiles of pasty foods was assessed by the power spectrum of the Fast Fourier Transform and the apparent fractal dimension of the curves. The same products were tested by a trained sensory panel for their smooth, soft, homogeneous and adhesive characteristics. The apparent fractal dimension, calculated through the dilation function of an image analysis system, gave a convenient measure of the overall capillary extrusion profile. It was hypothesized that this apparent fractal dimension represented the smoothness of the product which was correlated with the sensorial smooth character. The mean magnitude and the density of power spectra, determined by the Fourier analysis, were used to characterize the product consistency. Their shape was related directly to the smooth textural property.
RHEOLOGICAL BEHAVIOR OF LOQUAT (ERIOBOTRYA JAPONICA) JUICES
Authors: IBARZ A. , GARVÍN A. , COSTA J.
Published: February 2007

The rheological behaviour of two different loquat juices was studied. Juices containing pectins and pulp exhibited non‐Newtonian with yield stress behavior. Juices from which pectins and pulp were removed exhibited Newtonian behavior. The Bingham model described the relationship between shear stress and shear rate for the first type of juice and the Newtonian model described the second type. The effect of temperature on the Bingham plastic viscosity and the Newtonian viscosity was described by Arrhenius equation. The effect of soluble solids contents was described by power‐law and exponential expressions. Finally, two equations that described the combined effect of temperature and concentration were developed.
INELASTICITY AND BRUISING OF CHERRIES
Authors: BLAHOVEC J. , PATOČKA K. , PAPRŠTEIN F.
Published: February 2007

Cherries of three varieties were compressed between two plates in the loadingunloading test to determine the energy dissipated during the test. After compression, the bruise volume of the deformed fruit was determined. Bruise resistance coefficient (BRC) and bruise sensitivity (BS) were evaluated in a similar way as for apples. It is shown that, contrary to the results for apples, the BRC and BS values depend on the compression ratio in a more complicated way for cherries than for apples. The principal differences in bruise sensitivity were observed for different cherry varieties. These differences cannot be explained by the macroscopic mechanical properties of the fruits only.
INFLUENCE OF CHEWING EFFICIENCY ON TEXTURE AND FLAVOUR PERCEPTIONS OF FOOD
Authors: BROWN WENDY E. , DAUCHEL CÉLINE , WAKELING IAN
Published: February 2007

This study examined the effect of differences in chewing efficiency on selected panellists' perceptions of the stickiness and flavour of cooked pasta. Chewing efficiency was measured by the degree of breakdown of an almond, and weight loss of chewing gum after predetermined numbers of chews. Pasta was cooked for various lengths of time in tomato juice to provide a series of samples varying in texture and flavour. The attributes considered in this study were clearly understood and detected in all of the samples by all the subjects. Nevertheless the subjects differed in the time intensity representations of their perceptions of these attributes. Differences in the efficiencies with which subjects break down food in the mouth may account for the abilities of subjects to distinguish between samples in terms of texture and flavour.
DIVERSITY OF PERCEPTIONS OF MEAT TENDERNESS AND JUICINESS BY CONSUMERS: A TIME‐INTENSITY STUDY
Authors: BROWN WENDY E. , GERAULT STEPHANE , WAKELING IAN
Published: February 2007

Seven judges, untrained in sensory assessment, were trained in the use of Time Intensity (TI) and asked to monitor the tenderness and juiciness of a range of cooked beef and pork samples. The subjects were given no definitions concerning sensory cues to monitor in their assessments, nor did they confer with each other. The shapes of the TI curves they recorded for tenderness and juiciness differed between individuals, although there were similarities in the curve shapes for the 2 attributes for each individual. Correlations between the intensity parameters of the curves (maximum intensity and area under curve) and the chewing time were not significant for the subjects as a group for tenderness, although significant correlations were found for some of the subjects when examined individually. The results indicate that subjects differ in their concepts of sensory tenderness and juiciness, and that perceived tenderness does not correlate with chewing time for all subjects. In more general terms the study supports the use of TI assessments for interpreting individual differences in sensory perceptions.
FLOW BEHAVIOUR OF CALCIUM COMPLEXED HYDROXYPROPYL RICE STARCHES
Authors: ISLAM M. NURUL , AZEMI B.M.N. MOHD.
Published: February 2007

The flow behaviour characteristics of native, hydroxypropyl starches and their calcium complexes were determined at different levels of starch concentrations, temperatures and shear rates. Hydroxypropyl starch with different Molar Substitution (MS = 0.02–0.12) were used. Both native and hydroxypropyl starch were treated with varying amount of calcium (50–250 μg/g starch). Flow properties were affected due to hydroxypropylation and their calcium treatment. The flow properties were evaluated by power law equation.
OCCURRENCE OF RUPTURES ON THE SURFACE OF FOODS DURING FRYING
Authors: NAGAO KEIKO , HATAE KEIKO , SHIMADA ATSUKO
Published: February 2007

An attempt was made to clarify the mechanism of ruptures on the surface of foods occurring during frying. Two different products were fried in a corn oil bath at a temperature of 160C or 180C. One of the products was ellipsoidal croquettes coated by the crust with different thicknesses ranging from 1 mm to 4 mm, while the other was ring doughnuts consisting of the three different compositions of a fixed size. The type of ruptures on the crust of croquette samples could roughly be divided into two categories according to the results obtained by the precise observations during the process of frying, i.e., a small hole and a crack. The small hole, like a pinhole, occurred in the crust of the croquette with 1 mm thickness early in the procedure, while the cracks could be observed with the crusts of croquettes more than 2 mm thicknesses after 120 s or more of frying time. The cracks also occurred on the curved surface of all the doughnut samples tested, although the location of cracks on the three surfaces, i.e., upper, outer and inner, was much influenced by the composition of the samples. A variety of measurements were made to obtain information on the changes in mechanical properties of the core region and crusted surfaces of the samples in the frying process so as to confirm generalized simple considerations assumed for the occurrence of ruptures.
BOOK REVIEW
Authors: STANLEY D.W.
Published: February 2007

RHEOLOGICAL METHODS IN FOOD PROCESS ENGINEERING, SECOND EDITION. James F. Steffe, Freeman Press, East Lansing
IMPERFECT SQUEEZING FLOW VISCOSIMETRY OF NEWTONIAN LIQUIDS – THEORETICAL AND PRACTICAL CONSIDERATIONS
Authors: DAMRAU EVI , PELEG MICHA
Published: February 2007

Imperfect squeezing flow viscosimetry is an experimental procedure based on pressing a liquid specimen in a shallow container by a wide plate. Unlike in proper squeezing flow viscosimetry the specimen does not have a perfect cylindrical shape. Consequently, the flow regime is affected by factors other than squeezing and hence the name. Newtonian fluids, silicone oils of known viscosity and two honeys, were employed to evaluate the roles of the hydrostatic pressure and entry effects on the method's performance. Because of these, the shape of the initial part of the flow curve differs significantly from the ideal and it appears that a fully developed squeezing flow is only reached after a penetration of several millimeters. The magnitude of the viscosity calculated through nonlinear regression is extremely sensitive to the mathematical model used. Thus, added terms, to account for secondary effects, which improve the fit almost to perfection, can also result in a substantial error – or underestimate of the viscosity. Theoretical analysis shows that with a sensor of a size of Petri dish (plate and container diameters on the order of 120 and 140 mm respectively, and a specimen height on the order of 5 mm) the method is only suitable for fluids whose viscosity is in excess of about 100 Pa.s. Nevertheless, the method was still sensitive enough to monitor differences in the viscosity of commercial honeys which was merely on the order of 5–10 Pa.s at ambient temperature.
FAST FOURIER TRANSFORMATION ANALYSIS OF THE FORCE‐DISPLACEMENT CURVE AS A TEXTURE METHOD RELATED TO FRUIT MORPHOLOGY1
Authors: BRUSEWITZ G.H. , RIGNEY M.P. , ANZALDÚA‐MORALES A.
Published: February 2007

A method is proposed to quantify localized food texture by cutting through a cylindrical sample with a wire probe in an Instron universal testing machine. For probe wire diameters of 0.10, 0.63, 0.80, and 1.23 mm, finer wire was more sensitive to force changes for the fruit tested but required a preload tension and may not be strong enough for harder materials. A frequency analysis (FFT) was performed on the force‐displacement curves generated as the wire penetrated the sample. FFT peak energies were found at frequencies below 4 Hz for both a standard material and fruit. The first energy peak was the narrowest for a nonbiological material and widest for apples and pears. Peaches stored 28 days had three times more FFT energy in the lowest frequency band.
STABILITY OFCAPSICUM ANNUUMOLEORESIN‐IN‐WATER EMULSIONS CONTAININGPROSOPISANDACACIAGUMS
Authors: VERNON‐CARTER E. J. , PEDROZA‐ISLAS R. , BERISTAIN C.I.
Published: February 2007

Chilli oleoresin‐in‐water emulsions were stabilized with very low concentrations of mesquite (Prosopis juliflora), arabic (Acacia Senegal) and acacia (Acaciaspp.) gums at different pH values in order to establish which polysaccharide had the best emulsifying capacity and provided the best stability against droplet coalescence and pigment degradation. Mesquite gum was the best emulsifying and stabilizing agent, followed by gum arabic and acacia gum. In all cases, pH had a dramatic effect on the emulsion stability against droplet coalescence and color degradation. The stabilizing mechanisms governing these two deteriorative processes were opposite. While coalescence kinetics was hindered at high pH values, color degradation kinetics took place at a higher rate, while the opposite effect occurred at lower pH values. A number of factors were important in determining the emulsifying capacity, the droplet coalescence stability and the color degradation stability of the gums among them, the protein content, the molecular weight, the surface charge and the steric configuration adopted at different pH values.
ASSOCIATION OF PERCEPTUAL FEEL AND GENERAL DESCRIPTORS WITH FOOD CATEGORIES BY 8–11 YEAR OLDS AND ADULTS
Authors: ORAM NICHOLAS
Published: February 2007

This study assessed the association of perceptual feeling and general descriptors with food categories by Grade 3 (8–9 year olds), Grade 5 (10–11 year olds), and adults. Subjects judged whether 38 descriptors were appropriate for Bread and Cereals, Dairy Products, Fruit, Meat, Sweets, and Vegetables. The number of associations increased cumulatively with age. Three developmental trends were evident in this study in combination with an earlier one by Oram (1998). First, word‐category associations increased with age for words already in the food vocabulary. Second, words were associated with specific food categories before the superordinate label ‘Food'. Third, a few word‐category associations decreased from school‐age to adulthood. The first two trends may reflect increases with age in word comprehension, focussing on less salient attributes, and food category size. The third trend may be attributable to an agerelated shift in food typicality within individual categories. The present study also has several sensory evaluation implications. It shows an easy and quick way to estimate the vocabulary of children for food products, and the results of this study can be used to generate descriptor lists for 8–11 year olds.
SUITABILITY OF SINGLE‐COMPRESSION AND TPA TESTS TO DETERMINE ADHESIVENESS IN SOLID AND SEMI‐SOLID FOODS
Authors: FISZMAN S. M. , DAMÁSIO M. H.
Published: February 2007

Single compression tests were applied to carrageenan plus locust bean gum model gels (1:1) without sucrose and with 40% added sucrose, and two commercial samples of quince jelly containing high levels of sucrose (55 and 72 °Brix). The samples were glued to the main platform of the texturometer. The tests were performed up to two different levels of compression. Negative area (Aadh), the time that the samples remained adhering to the probe (tadh), and maximum negative force (Fmax) during the decompression stroke were determined. All the parameter values for the commercial samples were greater than those for the model systems. Aadh and Fmax were good indices of adhesiveness. The highest discriminative capacity in detecting sucrose levels of these two parameters was obtained at a low degree of compression; this could be because the samples had not suffered damage to their internal structure. Since the samples had high instantaneous recoverable springiness, the application of automated TPA proved inappropriate for obtaining a measurement of adhesiveness.
VISCOELASTIC PROPERTIES OF WHITE FRESH CHEESE FILLED WITH SODIUM CASEINATE
Authors: LOBATO‐CALLEROS C. , AGUIRRE‐MANDUJANO E. , VERNON‐CARTER E. J. , SANCHEZ‐GARCIA J.
Published: February 2007

The yield, moisture loss and viscoelastic properties of white fresh cheeses containing sodium caseinate were determined and compared to those of a reference cheese without sodium caseinate. Added sodium caseinate resulted in higher cheese yields and lower moisture losses during aging. Creep compliance tests were performed on the cheeses using a parallel plate viscoelastometer. Multiple regression analysis of the experimental data provided first order models that explain the variation of most of the viscoelastic parameters of the white fresh cheeses in terms of sodium caseinate level, moisture content, aging and pH. The instantaneous elastic compliance and the Newtonian viscosity increased with moisture content and pH, respectively. The retarded elastic compliances increased and the first retardation time decreased during aging. The influence of sodium caseinate on most of the viscoelastic parameters was significant.
INTERNATIONAL INTER‐LABORATORY TRIALS TO DETERMINE THE FACTORS AFFECTING THE MEASUREMENT OF CHOCOLATE VISCOSITY
Authors: AESCHLIMANN J.‐M. , BECKETT S. T.
Published: February 2007

The working group of the International Office of Cocoa, Chocolate and Sugar Confectionery (IOCCC) performed a sequence of five ring tests to improve the agreement of the standard method for measuring viscosity of chocolate between laboratories. Reporting shear stress measurements instead of using the Casson equation improved the agreement, as did standardising the method of cleaning the concentric cylinder and calibrating the viscometers. In the revised method, the standard deviation for shear stress measurement at shear rates greater than 5 s−1 from 23 laboratories was less than 8%. However, the Casson yield values had a seven‐fold range and the Casson plastic viscosity a two‐fold range, which was unacceptably high. A new method (IOCCC 2000) has been published as a result of this work and is available from CAOBISCO in Bruxelles, Belgium.
PRELIMINARY OBSERVATIONS ON EFFECTS OF FAT CONTENT AND DEGREE OF FAT EMULSIFICATION ON THE STRUCTURE‐FUNCTIONAL RELATIONSHIP OF CHEDDAR‐TYPE CHEESE
Authors: GUINEE T. P. , AUTY M. A. E. , MULLINS C. , CORCORAN M. O. , MULHOLLAND E. O.
Published: February 2007

Cheddar type cheeses of different fat contents were produced and denoted: full‐fat (FFC), 306g/kg; half‐fat (HFC), 174 g/kg; and low fat (LFC, 13 g/kg). Full‐fat Cheddar cheese (FFCH) was also prepared from milk which had been homogenized at first and second stage pressures of 25 and 5 MPa, respectively. The cheeses were held at 4C for 30 days and at 7C for the remainder of the 190‐day ripening period. Reducing the fat level from 174 to 13 g/kg resulted in decreases in contents of moisture in nonfat substance and pH 4.6 soluble N as a percentage of total N (pH4.6SN), and increases in the contents of moisture, protein and intact casein. Homogenization of cheesemilk resulted in a slight increase in moisture content and an increase in pH4.6SN. Confocal laser scanning microscopy revealed that the extent of fat globule clumping and coalescence in both the unheated and heated (to 95C) cheeses decreased with homogenization of the cheesemilk and with fat reduction. Homogenization of the cheesemilk and reducing the fat content of the cheese resulted in a decrease in the flowability and stretchability of the melted cheese. Dynamic measurement of the viscoelastic changes on heating the cheese from 20 to 90C showed that reduction of fat content resulted in a decrease in the magnitude of the phase angle, δ, at temperatures >50C. At temperatures<∼60C, the storage modulus, G', increased on reducing the fat content from 306–174 g/kg to 13 g/kg. Homogenization resulted in a marked decrease in δ at temperatures>45–50C, with δmax typically decreasing from ∼65–70° in the FFC to ∼35° in the FFCH.
SMALL DEFORMATION MEASUREMENTS OF SINGLE AND MIXED GELS OF LOW CHOLESTEROL YOLK AND EGG WHITE
Authors: PARASKEVOPOULOU ADAMANTINI , KIOSSEOGLOU VASSILIS , ALEVISOPOULOS STEFAN , KASAPIS STEFAN
Published: February 2007

Isolates of reduced‐cholesterol egg yolk were prepared by extracting cholesterol from spray‐dried yolk using the following solvents: (1) petroleum ether, (2) petroleum ether/ethanol, (3) ethanol/water and (4) supercritical carbon dioxide. Differential scanning calorimetry demonstrated that the temperature of minimum heat flow of the denatured isolates was about 75C. Mechanical properties of extracts were compared using small deformation oscillatory rheology. Ethanol/water and petroleum ether treated yolk had the strongest and weakest gelling characteristics respectively, following protein denaturation at 75C. When compared to egg white, yolk isolates formed stronger networks at 75C. Heating at higher temperatures denatured ovalbumin which produced slightly stronger gels than egg yolk. Binary mixtures of egg white and yolk formed phase separated gels. The best agreement between experimental data and calculated composite moduli by using isostrain and isostress Takayanagi models, was obtained for egg white keeping 37% more water per unit concentration than the egg yolk.
MECHANISMS OF FRACTURE IN FOODS
Authors: LILLFORD PETER J.
Published: February 2007

Most foods have solid‐like properties and therefore must be size reduced in the mouth before swallowing. In this paper we will examine the physics of the fracture processes involved in breaking different food types. These range widely from brittle fracture in dry cereal foods, nuts, and fresh vegetables, to the complex defibrillation and tensile failure in cooked meats. We will examine how the differences in fracture and failure processes correlate with our perception of quality in various food types. This allows deduction of an overall model for the mastication process and how consumers may develop preferences for particular foods. The real stresses and strains exerted in the mouth are difficult to identify in local, spacial detail. Recent work is beginning to define how mouth motion controls the fracture process, and the impact of saliva on the mechanism of swallowing.
MICROSTRUCTURE AND TEXTURE OF MANCHEGO CHEESE‐LIKE PRODUCTS MADE WITH CANOLA OIL, LIPOPHILIC AND HYDROPHILIC EMULSIFIERS
Authors: LOBATO‐CALLEROS C. , RAMÍREZ‐SANTIAGO C. , OSORIO‐SANTIAGO V. J. , VERNON‐CARTER E. J. , HORNELAS‐URIBE Y.
Published: February 2007

The effect of lipophilic and hydrophilic low‐molecular weight emulsifiers on microstructure and textural characteristics of Manchego cheese‐like products (MCLP) made from canola oil‐skim milk emulsions were studied. Nine emulsifier blends comprised of different proportions of polyoxyethylene sorbitan monostearate (P), sorbitan monostearate (S) and glycerol monostearate (G) were used to prepare the emulsions. A control cheese (MCFF) was made from whole milk. The cheeses were matured thirty days prior to Instrumental Texture Profile Analysis and Scanning Electron Microscopy analysis. High proportions of P in the emulsifier blend resulted in MCLP cheeses having smaller and individual oil droplets surrounded by a dense protein structure, which exhibited elevated values of hardness, springiness and chewiness, but low values of adhesiveness and cohesiveness. High proportions of G″ and S in the emulsifier blend yielded MCLP cheeses with larger and more agglomerated oil droplets immersed in a relaxed and porous protein matrix associated with less hard, springy and chewy, but higher cohesive and adhesive texture. The microstructural arrangement of the MCLP‐4 cheese (0.5P‐0.2S‐0.3G) showed texture closer to the MCFF cheese. Polynomial models were obtained that estimate the textural characteristics of the MCLP cheeses as a function of emulsifiers’ concentration.
DETERMINATION OF CHOCOLATE VISCOSITY
Authors: SERVAIS C. , RANC H. , ROBERTS I.D.
Published: February 2007

A critical appraisal of the Casson model for measuring chocolate versus a new proposed method is performed. The new method is validated with both research grade rheometers and factory grade viscometers. This includes elements of measurement uncertainty. In this way, a new reference method is validated for the viscosity of chocolate and related cocoa products using factory grade viscometers. It involves recording: (1) the value of the stress at a shear rate of 5s‐1to represent the yield stress of chocolate, (2) the value of the viscosity at a shear rate of 40s‐1to represent the high shear viscosity, and (3) the difference between the viscosity measured at a shear rate of 40s‐1during the ramp up and down in shear rate to represent thixotropy. Results relate to the solid to liquid glass transition of dispersions under applied stress, and it is shown that they reflect existing theories of stress induced formation and rupture of fractal aggregates, for particle crowded colloidal suspensions with low interaction energy.
EFFECTS OF TEXTURAL CHANGES IN COOKED APPLES ON THE HUMAN BITE, AND INSTRUMENTAL TESTS
Authors: DAN HARUKA , WATANABE HIROTAKA , DAN IPPEITA , KOHYAMA KAORU
Published: February 2007

A multiple‐point sheet sensor was used to measure the bite force applied to raw and cooked apple specimens during the first bite with incisors. Wedge penetration tests were compared with human bite measurements on the same samples. The shape of the force‐time curves during biting of cooked apples clearly differed from that for raw apples. The first curve of cooked apple biting became jagged, and the maximum force was reduced. The second curve emerged following the first curve in most subjects as a characteristic feature of cooked apple biting, whereas it was not seen in the bite curve of a raw specimen or the wedge penetration curve of a cooked specimen. The maximum force for tissue fracture decreased for cooked apples, but the duration of biting increased. No adequate counterparts for the impulse of biting could be obtained from the load‐displacement curves of the wedge penetration tests. The existence of parameters only measurable by bite tests and not by mechanical tests suggests the necessity of directly measuring the human bite.
VISCOELASTIC BEHAVIOR OF ARZÚA‐ULLOA CHEESE
Authors: TOVAR C.A. , CERDEIRIÑA C.A. , ROMANÍ L. , PRIETO B. , CARBALLO J.
Published: February 2007

A study of the viscoelastic properties of ten samples of commercial Arzúa‐Ulloa cheeses produced according to the regulations of the designation of origin is reported. The linear viscoelastic range at 20C was determined from stress sweep tests and later confirmed by transient tests. The shear creep compliance curves were analyzed in the framework of the generalized Burgers model. Mechanical spectra at 20C obtained from frequency sweep tests completed the study. The results thus obtained were highly consistent themselves and they manifested the structural differences among the samples. Some correlation between the dry extract content and the viscoelastic behavior was found.
STEADY‐SHEAR RHEOLOGY OF CONCENTRATED CHITOSAN SOLUTIONS
Authors: MARTÍNEZ A. , CHORNET E. , RODRIGUE D.
Published: February 2007

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RHEOLOGY, FOOD TEXTURE AND MASTICATION
Authors: NISHINARI KATSUYOSHI
Published: February 2007

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FOOD TEXTURE AND ITS EFFECT ON INGESTION, MASTICATION AND SWALLOWING
Authors: LUCAS P.W. , PRINZ J.F. , AGRAWAL K.R. , BRUCE I.C.
Published: February 2007

The oral processing of most semisolid and solid foods can be summarized in terms of two opposing mechanical influences: forces that fracture food particles versus those that make them adhere to each other. During either the ingestion of food into the mouth or the early stages of mastication, the aim of processing solid food particles is usually to fracture them. However, later on towards swallowing, adhesion is desirable in order to try to form a sticky food bolus that could clear the mouth of isolated food fragments. Neither of these tendencies is actually a function of any particular force (or stress) or displacement (or strain) on food particles, but is instead controlled by energy. Food particles can adhere not only to each other but to the mouth's surfaces. This produces friction. While this is essential for the tongue to grip food particles and move them around the mouth, it also adds to the work that mouthparts must do during processing and may affect sensory perception of food quality. Successful processing of foods in the mouth requires a considerable amount of neural feedback from sensory receptors. We focus here on recent evidence about these sensory receptors with an attempt to reinterpret their role in terms of textural perception.
TEXTURE PROFILE ANALYSIS AND COMPOSITION OF A MINCED CATFISH PRODUCT1
Authors: WILES J.L. , GREEN B.W. , BRYANT R.
Published: February 2007

Texture Profile Analysis of minced catfish products indicated that minced proteins from the belly flap meat have excellent functional properties to form gels or restructured products. Belly flap meat is considered a low‐value trimming, with about 16.9% protein and 11.2% total lipid. Washing of minced catfish trimmings increased the moisture content from 71.5% to 77.9% while reducing mechanical hardness (19.1 N to 11.9 N), chewiness index (14.2 N to 8.83 N) and shear energy (0.82 J to 0.51 J). No significant changes were found in cohesiveness, resilience, and springiness of the minced fish after washing or the addition of 3.3% (v/w) of 4% starch solution. Washing of minced fish reduced the total lipid content from 9.82% to 4.39%. Overall, washed minced channel catfish belly flap meat had functional characteristics that enabled its proteins to be formed and restructured. Products made from minced catfish had acceptable textural characteristics.
TOTAL QUALITY MANAGEMENT AND EMPLOYEE INVOLVEMENT
Authors: Wilkinson Adrian , Marchington Mick , Goodman John , Ackers Peter
Published: February 2007

Adrian Wilkinson and his colleagues discuss the growing importance of quality management in the UK, outline the basic principles of TQM, and examine its implications for employee involvement. They suggest that there are contradictions between the ‘hard’ and ‘soft’ sides of TQM. This can be exemplified in the relationship between TQM and employee involvement which has not been fully explored. Drawing on a major programme of research on employee involvement, three cases are analysed. They argue that the links between TQM and employee involvement are more complex than the TQM literature would have us believe and there are tensions between employee involvement and TQM. Finally, there is a wider discussion of the subject which analyses a number of constraints on the implementation of TQM in the UK.

Adrian Wilkinson, Mick Marchington and John Goodman are respectively Lecturer, Senior Lecturer and Professor in the School of Management at the University of Manchester Institute of Science and Technology. Peter Ackers is a Lecturer at Loughborough University Business School.
The Management of ‘Highflier’ Executives In France: the Weight of the National Culture
Authors: Bournois Frank , Roussillon Sylvie
Published: February 2007

Frank Bournois is Maître de Conférences (Senior Lecturer) in Human Resource Management at the Université Jean Moulin‐Lyon III, and Sylvie Roussillon is Head of the Human Resources Group at ESC Lyon (Lyon Graduate School of Business). These authors report here, for the first time, the results of a recent study into the particular practices used by French companies to identify and manage highflying executives. As preceding articles in this issue have shown, managerial élites are a key part of the French management system. This research reveals that the management of the highflier process is subtle, relatively unstructured, and informal – there is very little use made, for example, of assessment centres. A number of practical recommendations are made for those senior managers who are currently charged, or may in the future be charged, with the responsibility for the operation of this process.
Models of Personnel Management: A Means of Understanding the Diversity of Personnel Practices?
Authors: Monks Kathy
Published: February 2007

Kathy Monks, who is a Lecturer in Human Resource Management at Dublin City University Business School, discusses the results of a survey of the roles and responsibilities of personnel managers in Eire. She describes four main models of personnel practice which she found and compares them with those developed by Tyson and Fell in 1986 drawing on research in the UK. She goes on to consider why organisations adopt simple or complex personnel management pratices.
Can Commitment Be Managed? A Longitudinal Analysis of Employee Commitment and Human Resource Policies
Authors: Morris Tim , Lydka Helen , O'Creevy Mark Fenton
Published: February 2007

Tim Morris, Helen Lydka and Mark Fenton O'Creevy present data on a group of graduates during the first five years of employment. Dividing the sample into those who have remained with their original employer and those who have changed, they examine attitudinal commitment and tenure intentions against a set of human resource policies measured at three points in time. They find that those policies significantly associated with high commitment change over time; that attitudinal and behavioural commitment are conceptually distinct constructs; and that behavioural commitment is a less stable construct than attitudinal commitment. Generally, it appears that employee commitment is more provisional than is implied by much of the literature.

Tim Morris is a Lecturer at the London Business School, Helen Lydka a researcher at the Henley Management College, and Mark Fenton O'Creevy a Research Fellow at the LBS Centre for Organisational Research.
Procedures and Consistency Versus Flexibility and Commitment In Employee Relations: A Comment On Storey
Authors: Clark Jon
Published: February 2007

Jon Clark, who is Professor of Industrial Relations at Southampton University, comments on one of the most important issues raised in John Storey's Developments in the Management of Human Resources: the contrast between the ‘procedure and consistency’ of the IR/ personnel tradition and the ‘business need, flexibility and commitment’ of the HRM tradition. In particular, he queries whether HRM can be successful without a firm basis in ‘procedure and consistency’.
Managerial Culture and the Stillbirth of Organisational Commitment
Authors: Coopey John
Published: February 2007

The concept of organisational commitment continues to interest academics and practitioners despite evidence of low commitment in British companies. Explanations concentrate on why employees fail to respond to management policies or, more radically, on efforts to realign ‘corporate culture’. In this article the focus is changed by John Coopey to enable the effect of managerial culture on organisational commitment to be examined. the conceptual framework is of culture influencing individual attitudes via psychological processes (mediated through relationships). These themes are developed in a two‐fold argument: first managers are seen as entrapped in a culture that protects prerogatives through processes of accountability and hence, second, managers find difficulty in acting as exemplars of organisational commitment for potential followers.
The Management Training Industry In the Uk: an Hrd Director's Critique
Authors: Mole Graham
Published: February 2007

What passes for management training in the UK is largely atheoretical, delivering undifferentiated prescriptions around a few popular management themes. It persists in this mode despite well‐researched practices which can enhance the effectiveness of training. the behaviour of the main actors involved is examined for possible causes of this ‘genre training’ phenomenon. Consideration is given to why management trainers, sponsors of management training and trainees find it preferable – for various but coinciding interests – to favour conformity to training course stereotypes rather than attempt to meet real needs. the pessimistic conclusion is that unless the wide gap between research and application can be narrowed, possibly by senior management making training practitioners more accountable for the return on investment in training, mediocrity in management training will continue.
Practices and Practicalities In Human Resource Management1
Authors: Ezzamel Mahmoud , Lilley Simon , Wilkinson Adrian , Willmott Hugh
Published: February 2007

A wide‐ranging research project covering change and its implementation in 27 companies provides the opportunity for the authors of this article to reassess the meaning and significance of HRM. They suggest that ‘it is too simple to dismiss HRM as “old wine in new bottles”.’ Rather, they find important changes taking place. But the true significance of HRM, they suggest, lies not in the fact that its practice actually does resolve underlying tensions but rather in its capacity to ‘manage’ these by ‘reducing, suppressing and glossing’ them. HRM itself is an outcome of the tensions in the employment relationship and, perhaps not surprisingly therefore, it continues to express them. the article ends with suggestions for future research.