bluuebunny/crossref_metadata_2025 huggingface dataset:
DEPENDENCE OF THERMAL PROPERTIES AS WELL AS NETWORK MICROSTRUCTURE AND RHEOLOGY ON PROTEIN CONCENTRATION FOR OVALBUMIN AND VICILIN
Authors: ARNTFIELD S. D. , MURRAY E. D. , ISMOND M.A.H.
Published: February 2007

Critical protein concentration (CPC) values for network formation for ovalbumin (5.5%, w/w) and vicilin (8%, w/w) were determined based on the appearance of a well crosslinked network using light microscopy, in conjunction with a significant decrease in the dynamic rheological parameter, tan δ= G″/G′. Increasing protein concentration resulted in increased G′ (storage modulus) and G″ (loss modulus) for both proteins. These relationships were described by power law equations. Ovalbumin networks had a lower CPC and tan δ value at protein concentrations above the CPC than did vicilin networks. This was related to a greater increase in the G′ and G″ moduli during the initial stages of cooling.
MODELING RHEOLOGICAL BEHAVIOR OF GELATINIZING STARCH SOLUTIONS USING MIXER VISCOMETRY DATA
Authors: DOLAN KIRK D. , STEFFE JAMES F.
Published: February 2007

A Brookfield RVTD mixer viscometer was used to gelatinize 5.5, 6.4, and 7.3% (d.b.) native corn starch solutions, and a 6% bean starch solution. Torque, the dependent variable, was used to estimate parameters in a generalized viscosity model. The independent variables were impeller speed, temperature (50–95°C), concentration, temperature‐time history, and strain history. The starch dispersions thickened with decreasing temperature and had an Arrhenius activation energy between 6.4 and 12.7 kJ/mol. There was no evidence that retrogradation caused this effect. First‐order reaction kinetics was accurate (9.8% standard deviation) in describing viscosity increase during gelatinization. After initial gelatinization, torque decayed exponentially with time. Predicted curves followed experimental pasting curves when interactions among the independent variables were accounted for in the model. The major variables controlling the pasting process were temperature‐time history before peak torque, strain history between peak torque and cooling, and temperature during cooling.
EFFECT OF ADDITION OF α‐, β‐, AND κ‐CASEIN, AND Na‐CASEINATE ON VISCOELASTIC PROPERTIES OF SKIM MILK CURD
Authors: HALIM H. K. , SHOEMAKER C. F.
Published: February 2007

Creep compliance was used to determine the effects of the addition of α‐, β‐, and κ‐casein, and Na‐caseinate on the viscoelastic properties of skim milk curd. The results of all measurements can be represented by a six‐element mechanical model. Addition of α‐ and β‐casein, and Na‐caseinate (1.80g/L) to raw skim milk reduced the instantaneous modulus of rigidity and final viscosity of the curd, while κ‐casein addition at the same level increased both viscoelastic parameters. Shielding of κ‐casein and depletion of serum Ca++ ions by α‐ and β‐casein is thought to have caused the reduction of curd rigidity and viscosity. Subsequent experiments indicated that the addition of β‐casein before and after rennet hydrolysis produced different curd strength with the latter producing a stronger curd.
TEXTURE AND MICROSTRUCTURE OF AFRICAN YAM BEAN (SPHENOSTYLIS STERNOCARPA) PRODUCTS
Authors: ENWERE N. J. , HUNG Y.‐C. , NGODDY P. O.
Published: February 2007

The microstructure of African yam bean (Sphenostylis sternocarpa) cotyledons, flour, starch and gel prepared from flour were examined using scanning electron microscopy. Smooth starch granules varying in size and shape were embedded in the protein matrix. The starch granules maintained their integrity in the flour after milling. The texture profile parameters of starch and flour gels were studied at both 50 and 75% double compression and relaxation levels using the Instron Universal Tester. Significant variations were observed in the texture of the top and bottom portions of the gel. Increased solid content from 10.00% to 25.04% significantly increased the hardness of yam bean gel; however, further increase of solid content to 30.80% had only limited effect. Addition of oil decreased hardness of plain gel which may be due to the shortening and softening effects.
SENSORY AND MECHANICAL ASSESSMENT OF THE QUALITY OF FRANKFURTERS
Authors: BEILKEN S. L. , EADIE L. M. , JONES P. N. , HARRIS P. V.
Published: February 2007

A sensory profile was established for quantifying the texture and flavor of frankfurter‐type sausages. The technique of Free Choice Profiling was used to enable panelists to set up and test their individual sensory profiles using their own list of descriptors or attributes. These profiles were then converted to a consensus or Fixed Choice profile by group discussion and rationalisation. Consensus profile sensory results were compared with results obtained using various compression and punch tests on samples at both room temperature (22°C) and 50°C. Compression tests related best to the sensory data and increasing the sample temperature to 50°C significantly (P<0.001) improved the objective‐sensory relationships.
DYNAMIC VISCOELASTIC PROPERTIES OF SOME COMMERCIAL SALAD DRESSINGS
Authors: MUÑTOZ J. , SHERMAN P.
Published: February 2007

A controlled stress rheometer (Carrimed CS) was used to carry out oscillatory viscoelastic experiments within the linear viscoelastic region for some commercial salad dressings: mayonnaise, reduced calorie mayonnaise and salad creams. All the mayonnaise samples exhibited higher values of maximum stress amplitude which guarantee linear viscoelasticity than either the reduced calorie mayonnaise samples or salad creams.

The frequency dependencies of the storage modulus and the phase angle revealed that all the standard mayonnaise samples exhibited similar viscoelastic properties, showing a higher elasticity than the reduced calorie mayonnaise samples and these, in turn had a higher elasticity than salad creams.

The absolute magnitude of the complex viscosity, |η*|, followed the power law equation with respect to frequency except for the salad creams and was compared to the steady viscosity, η. |η*|/η was related to the degree of shear destruction in the structure, which was minimum for one of the reduced calorie mayonnaise samples.

The viscoelastic properties of the salad dressings studied are related to their different structures.
RECOVERABLE WORK VERSUS ASYMPTOTIC RELAXATION MODULUS IN AGAR, CARRAGEENAN AND GELLAN GELS1
Authors: NUSSINOVITCH A. , KALETUNC G. , NORMAND M. D. , PELEG M.
Published: February 2007

Cylindrical specimens of agar, carrageenan and gellan gels (1&2%) were uniaxially compressed to various predetermined strain levels and then decompressed. In an independent set of tests, specimens of the same gels were compressed to the same strains and then allowed to relax. Both the percent recoverable work, calculated from the stress‐strain relationships in the compression‐decompression cycles and the magnitude of the asymptotic relaxation modulus, calculated from the normalized and linearized relaxation curves, decreased as the strain increased. In all three gels there was a linear correlation between the percent recoverable work and the magnitude of the asymptotic modulus at corresponding strains, a sign that both parameters are indicative of these gels’ degree of elasticity and the latter's strain dependency.
PALATAL PRESSURE PATTERNS OF GELATIN GELS IN THE MOUTH
Authors: TAKAHASHI JUNKO , NAKAZAWA FUMIKO
Published: February 2007

Palatal pressures of gelatin gel at various concentrations were detected by pressure transducers set at three locations in the palate. The following parameters were derived from the palatal pressure patterns: P, mean of palatal pressure from the beginning of eating to the end of swallowing; S, the last pulse of swallowing; T, retaining time of the sample in the mouth and W, energy consumed in the course of time until swallowing. P and W increased as the gelatin concentration increased from 1.0–4.0% and then they decreased as the gelatin concentrations exceeded 4.0%. T increased linearly over the whole range of gelatin concentrations. Changes in gelatin concentration had little effect on S. It was concluded that oral action changed primarily from crushing by the tongue against the palate to biting by the teeth as the toughness of the gelatin gel increased.
NONLINEAR RHEOLOGICAL BEHAVIOR CHARACTERIZATION OF SOLID FOODS
Authors: LEITE D. M. B. , PIAZZA L. , MASI P.
Published: February 2007

Nutting's general law of deformation was used to characterize the nonlinear rheological behaviour of bread. A simple experimental technique submits a sample of regular geometry to a sequence of compression runs in which the ultimate strain, or the ultimate load, was kept constant. In order to avoid sample failure as a consequence of mechanical fatigue an ultimate strain as low as 5% and an ultimate load of 150 g were chosen. An extremely good agreement (correlation coefficient 0.9997) between the model prediction of bread stress‐strain behaviour and the experimental results was found up to 80% compression. This result appears quite promising since it provides a simple way to predict and compare material performances under very large deformations.
RHEOLOGICAL BEHAVIOR OF PROCESSED MUSTARD. I: EFFECT OF MILLING TREATMENT
Authors: AGUILAR C. , RIZVI S. S. H. , RAMIREZ J. F. , INDA A.
Published: February 2007

The influence of milling level on the rheological behavior of processed mustard was investigated using three different particle sizes (slightly‐coarse, standard, and fine) prepared according to a standard formulation and pilot‐plant replication of the commercial methodology. All samples showed unimodal population‐based particle size distributions which were described by the population‐mode (dpop). On a volume basis, all milling levels had well‐defined bimodal distributions consisting of a smaller‐ and a larger‐size group of particles described by their modes (d and D). The most important particle size index in relating milling level to rheological behavior was not the population mode (dpop) but the larger‐size volume mode (D) from the bimodal distribution. The coarser the milling, the higher the larger‐size volume mode (D), and higher the values of: a) Apparent viscosity of nonmixed samples (ηp), b) Bingham yield stress (o−o) and plastic apparent viscosity (σp), c) Shear stress constant (A) and coefficient of thixotropic breakdown (B) from the Weltman stress decay model, d) Yield stress (o−o) and consistency index (K) from the Herschel‐Bulkley model, and e) Storage (G1) and loss (G”) moduli. As indicators of structure‐texture relationship, the above rheological parameters can be profitably utilized to study the effect of manufacturing practices on long term storage stability of the product.
BOOK REVIEW
Authors: RAO M. A.
Published: February 2007

BATTERS AND BREADINGS IN FOOD PROCESSING. American Association of Cereal Chemists, Inc., St. Paul, Minnesota.
CREAMY PERCEPTION II: IN MODEL SOUPS
Authors: DAGET N. , JOERG M.
Published: February 2007

Model cream soups prepared with different levels of several thickeners were evaluated by a panel who scored their liking of consistency, perceived creaminess and thickness. Their viscosities were measured with a Haake viscometer. The perceived thickness is linearly related to the logarithm of viscosity for all thickeners. Liking consistency shows a quadratic relation with viscosity. Perceived creaminess changes according to the type of thickener. The optimal values of viscosity and flow behaviour index for maximum creaminess and best liking consistency do not coincide. The viscosity and the flow behavior index affect the sensorial responses of liking consistency and creaminess. Response surfaces show that other rheological factors affect the model. The results for soups are compared with result for creams from a previous study. The viscosity for maximum creaminess is higher for creams than for soups while the flow behaviour is higher for soups than for creams.
BRUISING AND SPLITTING OF APPLE FRUIT UNDER UNI‐AXIAL COMPRESSION AND THE ROLE OF SKIN IN PREVENTING DAMAGE
Authors: KHAN ALI A. , VINCENT JULIAN F. V.
Published: February 2007

Whole apples were compressed uni‐axially with the core at right angles (horizontal compression) and parallel (vertical compression) to the direction of force. Under horizontal compression, the apple begins to bruise as soon as force is applied. The energy absorbed is proportional to the volume of bruise produced. Resistance to bruising varies with variety. In this orientation the fruit does not deform elastically, bruises easily, and the skin is not important in preventing bruising. Under vertical compression the apple is a much more elastic structure and can expand laterally. It can withstand greater deformation without damage. Rock Pippin can elastically absorb up to 0.5 J before damage. In this orientation, skin plays an important part in preventing cracking under tension. Any damage to the skin greatly reduces the structural strength of the fruit and renders it much more susceptible to cracking. Apples stacked in boxes seldom experience energies greater than 0.5 J. Storing apples in a vertical orientation can therefore reduce risk of bruising.
RHEOLOGICAL PROPERTIES OF PROTEIN/STARCH MIXED GELS
Authors: MUHRBECK P. , ELIASSON A.‐C.
Published: February 2007

The influence on the viscoelastic behaviour of the heat transition temperatures of starch and protein in gelatinous systems prepared from the two components was studied. Four different starches were combined with Bovine Serum Albumin (BSA) in several protein‐to‐starch ratios. Both the transition temperature and the rates of gelation of the components were critical for the behaviour of the complex systems. In those cases where the starch gel was formed before the protein gel, the storage and loss moduli of the complex system could be predicted by a simple addition of the moduli of the components at corresponding concentrations. When the gelation occurred in the reverse order, the gels were considerably stronger than predicted by the additivity model. When the starches were combined with gelatin, the complex gels were all weaker than predicted. The gelation of gelatin was very slow compared to that of the starches and the BSA, and it is likely that the weakness of these gels was due to the aggregation of the amylose molecules or some other part of the starch retrogradation process.
RHEOLOGICAL INDICES OF FRUIT CONTENT IN JAMS: INFLUENCE OF FORMULATION ON TIME‐DEPENDENT FLOW OF SHEARED STRAWBERRY AND PEACH JAMS
Authors: CARBONELL E. , COSTELL E. , DURÁN L.
Published: February 2007

The influence of formulation factors [fruit content (25–55%), soluble solids content (60–70° Brix) and added pectin (0.3–0.7% in strawberry jams and 0.1–0.5% in peach jams)] on time dependent parameters has been analyzed in previously sheared jams. Twenty three samples of each fruit jam were prepared according to a second order composite rotatable design. Weltmann A values depended mainly on fruit content and on its interaction with the other two composition factors for both fruit jams. Weltmann B values, depended on the three variables and on fruit‐pectin interaction for strawberry jams, while for peach jams B values depended also on fruit‐soluble solids interaction.

Predictive power of time dependent parameters for estimation of fruit content was low, but considering them in conjunction with soluble solids content and total pectin values explained 91.7% of the variability of fruit content in strawberry jams and 83.7% of same in peach jams.
STRAIN HARDENING OF DOUGH AS A REQUIREMENT FOR GAS RETENTION
Authors: VAN VLIET T. , JANSSEN A.M. , BLOKSMA A.H. , WALSTRA P.
Published: February 2007

Mechanisms that can be responsible for the ability of wheat flour doughs to retain gas are discussed. It is concluded that the relevant types of physical instabilities are Ostwald ripening (disproportionation) and coalescence of gas cells. The extent of Ostwald ripening is probably primarily controlled by surface rheological properties; it certainly affects crumb structure, but it cannot explain the differences in gas retention among doughs from various cereals or various wheat cultivars. It is argued that surface forces only provide a stabilizing mechanism for dough films between gas cells, i.e., against coalescence, for films that are much thinner than the diameter of a starch granule. It is concluded that variation in the potential for gas retention among wheat flour doughs is largely due to variation in bulk rheological properties. We propose a new rheological criterion for the extensibility of dough films between gas cells (and thereby for gas retention) that is based on the strain hardening of the dough in biaxial extension exceeding a specific lower limit. The criterion is translated into measurable parameters. Preliminary experiments on doughs with poor and with satisfactory baking performance illustrate its potential importance.
FAILURE MECHANISMS OF TOMATO PERICARP TISSUE SUGGESTED BY LARGE AND SMALL DEFORMATION TESTS
Authors: JACKMAN ROBERT L. , STANLEY DAVID W.
Published: February 2007

Failure mechanisms of tomato pericarp tissue were investigated by measuring puncture and viscoelastic properties of tissue from fruit stored at 22C (nonchilled) or 5C (chilled) for 28 days, or at 5C for 15 days prior to transfer to 22C for an additional 13 days (prechilled) to facilitate ripening. The puncture properties of tissue remained unchanged during 28 days of chilling. However, tissue shear strength and rigidity increased with chilling, as demonstrated by increases in storage and loss moduli, and decreases in oscillatory strain and the loss tangent. Puncture failure force, failure firmness and storage and loss moduli of nonchilled and prechilled tissues decreased to low, constant levels by 12 and 9 days, respectively. Simultaneously, pseudoplastic and failure strains and oscillatory strain each increased. These data suggest that the loss of tissue compressive strengths and transition in the dominant mode of failure from cell relaxation and rupture to cell debonding occurred at a faster rate during ripening of prechilled (i.e., chill‐injured) compared to nonchilled fruit.
TWIST TEST FOR MEASURING FRUIT FIRMNESS
Authors: STUDMAN CLIFFORD J. , YUWANA
Published: February 2007

A new test for measuring in‐situ crushing strength of flesh of a range of fruits and other crops is described. The device consists of a blade on a spindle, which is pushed into the fruit and rotated about the axis of the spindle. The resisting moment is measured by an offset arm arrangement. The tester can measure fruit properties in‐situ at any depth, including the core of the fruit. This has advantages for fruits that ripen from the centre, or where internal properties are more important than those close to the surface. Each full test can be completed in under 15 s. The tester is easier to use and more reliable than a conventional penetrometer. Some typical experimental results conducted on kiwifruit and apples harvested at various stages of growth and maturation are presented.
THE PSYCHOPHYSICS OF POURING, SPREADING AND IN‐MOUTH VISCOSITY
Authors: ELEJALDE CESAR C. , KOKINI JOZEF L.
Published: February 2007

The sensory viscosity of low calorie viscoelastic syrups in the mouth, while pouring out of a bottle, and spreading over a flat surface was satisfactorily estimated from the fundamental physical properties of these fluids. Appropriate sensory perception mechanisms were identified and linked to the operating conditions of each sensory test through psychophysical models. Oral sensory viscosity correlated with the shear stress in the mouth (R2= 0.96) (Kokini et al. 1977); pouring sensory viscosity correlated with the cross sectional area filled by the fluid at the neck of the bottle (R2= 0.86); and spreading sensory viscosity correlated inversely with the radial growth of the spreading fluid puddle (R2= 0.96).
EFFECT OF SPRAY‐DRIED OR REDUCED‐CHOLESTEROL YOLK AND TEMPERATURE ON THE LINEAR VISCOELASTIC PROPERTIES OF MAYONNAISE
Authors: GUERRERO ANTONIO F. , BALL HERSHELL R.
Published: February 2007

The dynamic viscoelastic properties of five mayonnaise products were evaluated at 5–30C and 0,031‐31,4 s−1. The composition of the products was held constant, while the type of egg product was varied. Two egg yolks (native and spraydried) and three whole egg products (native, dried‐yolk containing and low‐in‐cholesterol‐yolk containing) were used as the emulsifiers. Temperature generally produces a decrease in the viscoelastic functions. A replacement of yolk (native or not) by egg white reduces the viscoelastic properties of mayonnaise. Processed yolk gives rise to greater viscoelastic parameters than native yolk. This effect loses significance when yolk is diluted by native egg white. The low‐cholesterol mayonnaise has similar viscoelastic properties when compared to commercial mayonnaise.
EFFECT OF PARTICLE SIZE ON VISCOAMYLOGRAPHIC BEHAVIOUR OF RICE FLOUR AND VERMICELLI QUALITY
Authors: ATHY J. HEMA V , BHAT K.K.
Published: February 2007

The effect of particle size on the cooking behaviour of rice (Oryzae sativa, sub sp. Indica kato) flour was studied with the Brabender Viscoamylograph. Among the flours of different average particle sizes (307, 214, 165, 138, 114, 90 and 71 μ) studied, flours of 138 and 165 μ showed high breakdown ratios of 0.984 and 0.866 and set back ratios of 2.333 and 2.143, respectively. Comparatively, for vermicelli making, the flours of 138 and 165 μ yielded a product with better scores for textural profile, highlighting the importance of particle size of flours in the preparation of rice based vermicelli.
RHEOLOGICAL BEHAVIOUR OF COCOA DISPERSIONS
Authors: FANG T. N. , TIU C. , WU X. , DONG S.
Published: February 2007

The steady‐shear viscosities of cocoa mass and cocoa suspensions were measured over a wide range of temperature and cocoa powder content. The effects of gasification, moisture and lecithin contents were also investigated. The viscosity of cocoa mass followed the Quemada or the Casson model. Both viscosity and yield stress decreased with increasing temperature. Degasification also lowered the viscosity and yield stress. The viscosity of concentrated cocoa suspension increased with increasing powder content and exhibited shear‐thinning behaviour, and followed the Kreiger and Dougherty model. While the relative intrinsic viscosity was nearly constant, the maximum volume fraction increased with increasing shear stress or shear rate. Addition of moisture in suspension increased the viscosity due to partial gelation of starch; while addition of lecithin decreased the viscosity due to the lesser number of flocs in the suspension.
TEXTURAL PROPERTIES OF STARCH GELS FILLED WITH COLLAGEN AND CHITIN
Authors: INABA HISAJI , HOSHIZAWA MASATAKA , FUJIWARA AKIRA , MATSUMURA YASUKI , MORI TOMOHIKO
Published: February 2007

Chitin and collagen powders were added as fillers to various starches (potato, sweet potato, kudzu, corn, wheat, and mung bean), heated at 100C for 10 min with stirring to make a hot paste and allowed to gel quiescently at 5C for 2 h in order to investigate the effects of the filler particle on the texture of the gels. The parameters of hardness, cohesiveness and adhesiveness were determined instrumentally and compared. The filler particles of collagen and chitin were effective in increasing hardness of corn starch gels but had no effects on hardness of the potato, sweet potato, kudzu, wheat and mung bean starch gels except at the lower starch concentrations. Cohesiveness was increased slightly in all starch gels by addition of collagen whereas chitin addition only increased the cohesiveness of sweet potato and mung bean starch gels. Collagen and chitin addition increased adhesiveness all of starch gels, but the intensity of the effect was most remarkable for collagen. The observed differences in effects was apparently due to differences in the interactions between starches and filler particles arising from differences in the surface properties of the filler particles.
SENSORY AND RHEOLOGICAL PROPERTIES OF K‐CARRAGEENAN GELS MIXED WITH LOCUST BEAN GUM, TARA GUM OR GUAR GUM
Authors: MURAYAMA ATSUKO , ICHIKAWA YOKO , KAWABATA AKIKO
Published: February 2007

Mixed gels of K‐carrageenan (C) and a galactomannan gum, viz., locust bean (L), tara (T), and guar (G) in ratios of 7:3 and 1:1 (total concentration 1%), were examined for their rheological properties and by a sensory evaluation. Texture, creep and rupture were measured, and the semantic differential method (SD) was employed. K‐Carrageenan alone could not form a gel at the concentration of 0.5%, while C‐L and C‐T but not C‐G mixtures in the ratio of 1:1 formed gels. The mixed gels of C‐L were hard, very elastic and not perceived as smooth by the sensory evaluation. The values for the gels comprising T were intermediate between the C‐L and C‐G gels in instrumental measurements and sensory characteristics, indicating that the C‐T mixture performed well as an edible gel. This difference is attributed to the synergistic effect between K‐carrageenan and the gums.
FLOW BEHAVIOR OF REGULAR AND PEANUT‐FORTIFIED IDLI BATTERS
Authors: CASTELL‐PEREZ M.E. , MISHRA A.K.
Published: February 2007

Regular and peanut‐fortified idli batters showed shear‐thinning behavior before and after fermentation. Fermentation increased batter viscosity and degree of shear thinning of regular and peanut‐fortified batters. Fortification with defatted peanut flour (DPF) (up to 20%) significantly increased viscosity and the batters became more shear thinning at the 25–30% DPF fortification level.
INTERACTIONS BETWEEN FOOD COMPONENTS IN ICE CREAM II: STRUCTURE‐TEXTURE RELATIONSHIPS
Authors: GELIN J.‐L. , POYEN L. , RIZZOTTI R. , DACREMONT C. , LE MESTE M. , LORIENT D.
Published: February 2007

The effect of four composition factors on fat destabilisation, melting resistance and sensory characteristics were studied in hardened ice creams by the means of principal components analysis (PCA). For all the proteins, PCA revealed a pronounced contrast between ‘coldness’ and ‘creaminess’ in ice cream. The third sensory descriptor ‘length in mouth’ was either correlated with ‘creaminess’ for skim milk powder (SMP) and whey protein concentrate (WPC) series, or with ‘coldness’ in the case of the skim milk replacer (SMR) series. In each calculation, the butteroil was not correlated with ‘creaminess.’ In the case of SMP ice cream the descriptor ‘creaminess’ was strongly correlated with a small initial droplet size and with a high fraction of fat destabilised: the initial droplet size was itself associated with a high ratio emulsifier to butteroil. For both SMR and WPC ice cream, creaminess was not correlated to the extent of fat destabilisation in ice cream.
DETERMINATION OF THE APPARENT FRACTAL DIMENSION OF THE FORCE‐DISPLACEMENT CURVES OF BRITTLE SNACKS BY FOUR DIFFERENT ALGORITHMS1
Authors: BORGES ANTJE , PELEG M.
Published: February 2007

The apparent fractal dimension of digitized experimental force‐displacement curves of cheese balls and Zwiebacks at various levels of water activity were determined with the Richardson, Minkowski, Kolmogorov and Korcak algorithms. All four, but especially the first three, produced a consistent dimension despite the fact that the curves themselves were not truly fractal. These calculated dimensions were effective jaggedness measures and could be used interchangeably to monitor moisture sorption effects on the shape of force‐displacement relationships. The apparent dimension versus water activity plot had a sigmoid form which was characterized by a shifted Fermi equation. The center point of the jaggedness loss as well as its span was revealed from the magnitude of the equation's constants or directly from the plot.
EFFECTS OF GUAR GUM AND MICROCRYSTALLINE CELLULOSE ON SENSORY AND THERMAL PROPERTIES OF A HIGH FAT MODEL FOOD SYSTEM
Authors: LAWLESS HARRY T. , TUORILA HELY , JOUPPILA KIRSI , VIRTANEN PAULA , HORNE JOHN
Published: February 2007

Descriptive sensory analysis, time‐intensity (TI) profiling and differential scanning calorimetry (DSC) were used to study the textural and thermal properties of a confectionary‐like model food system consisting of cocoa butter, sucrose and an aromatic flavorant. Varying amounts of microcrystalline cellulose (MCC) and guar gum were substituted for cocoa butter at levels ranging from 5% to 20% (by weight), alone and in combination. Descriptive analysis of the following attributes was conducted: aroma, sweetness, total flavor, hardness, fracturability, adhesiveness, cohesiveness, amount of particles, particle size, smoothness llum‐piness, viscosity of the melted mass, melt rate, mouth drying, residual amount of particles and mouthcoating. Added fat substitution decreased sweetness, flavor and the rate of melting. Increases were seen in viscosity, perceived amount of particles, hardness, adhesiveness, mouthcoating and mouth drying. These changes were concentration dependent and were more pronounced for guar than for MCC. TI changes in sweetness, melting and overall flavor paralleled the descriptive panel results, with the largest effects observed in the 20%/20% mixture of guar gum and MCC. Melting enthalpies determined using DSC suggested a lowered degree
A MICRO‐PENETRATION TECHNIQUE FOR MECHANICAL TESTING OF PLANT CELL WALLS
Authors: HILLER S. , BRUCE D.M. , JERONIMIDIS G.
Published: February 2007

A close examination of mechanical “noise” produced during the cutting of potato tuber parenchyma tissue suggested that the signals reflected the summation of the stretching and breaking of individual cell walls. Replacement of the cutting blade by a thin parallel‐sided glass probe, together with the use of very sensitive load‐ and deflection‐transducers, produced a micro‐penetration test capable of resolving individual cell‐wall stretching and breaking events. The use of such data to provide information about mean cell diameters, cell wall fracture energies and cell wall stiffness, together with associated limitations, is discussed.
AN EMPIRICAL MODEL FOR THE STRESS‐STRAIN RELATIONSHIPS OF HYDROCOLLOID GELS IN TENSION MODE
Authors: HERSHKO V. , NUSSINOVITCH A.
Published: February 2007

The mechanical properties of hydrocolloid gels with high gum concentrations (agar 1–5%, gellan 1–3% and K‐carrageenan 0.5–3.0%), were measured under uniaxial tension. A simple power law model was used to describe the stress‐strain curves which tended to be concave upward. The overall stiffness and the extent to which the stress‐strain curve deviated from a straight line were estimated by the calculated constants of this model, using linear regression of the model's logarithmic transform.
RESPONSE OF BANANAS AND PLANTAINS TO IMPACT FORCES
Authors: KAJUNA S.T.A.R. , BILANSKI W.K. , MITTAL G.S.
Published: February 2007

Banana and plantains were obtained at green firm stage and stored at 20C and 90% relative humidity for up to 11 days. Some of the fruits were removed each day from storage and subjected to three impact energy levels (0.206, 0.514 and 0.828 J) using a specifically designed impacter. The impacted fruits were incubated at the same storage conditions for 24 h before assessing the bruise volume. Two models relating the bruise volume, the impact energy and the storage time were developed for both fruits. For bananas, the bruise volume had a linear relationship with the energy absorbed by the fruits, whereas the relationship was nonlinear for plantains. Plantains seemed to sustain less bruise volume than bananas during the initial storage period, but their bruise volume increased much faster in the subsequent storage days than bananas.
BOOK REVIEW
Authors: SHERMAN P.
Published: February 2007

ENCYCLOPEDIA OF EMULSION TECHNOLOGY
EFFECT OF PROTEIN HYDROLYSATE ON THE INSTRUMENTAL TEXTURE PROFILE OF GELATIN GELS
Authors: SURÓWKA KRZYSZTOF
Published: February 2007

The texture of gels containing 2 to 8% of gelatin and 1 to 10% of alcalase protein hydrolysate obtained from poultry meat was examined using the instrumental texture profile analysis (TPA) method in compression and penetration mode. Response surface analysis modelled the effects of the two components of the gels on textural properties. In both tests the addition of hydrolysate decreased hardness and chewiness, and the effect was more pronounced for higher gelatin concentrations. The senses of changes in cohesiveness and springiness as measured in both tests employed here were not in agreement with each other owing to different consequences produced on the sample. In the case of compression, both parameters decreased with increased hydrolysate addition, whereas for penetration an increase in cohesiveness was observed as well as small changes in springiness. Hydrolysate produced a statistically significant negative linear and positive quadratic effect with regard to the majority of the studied texture parameters. This component interacted significantly with gelatin with regard to hardness, chewiness, and fracturability which led to a decrease in the first two and an increase in the last texture parameter. The weakening effect of the protein hydrolysate upon texture may be of great importance for the quality of gelatin gels.
MULTIPARAMETRIC METHOD FOR THE RHEOLOGICAL EVALUATION OF MEAT AND OTHER SOLID FOODS
Authors: TYSZKIEWICZ S. , OLKIEWICZ M. , DAUN H.
Published: February 2007

Continuously Alternating Stress‐Relaxation Analysis (CASRA) was automated and adopted to the Zwick Universal Testing Machine. The method permits characterization of rheological properties of meat and other foods by applying sequentially increasing loads, alternating with a relaxation period of equal duration, until the structure collapses. Three parameters: plasticity, P, elasticity, E, and fluidity, F are derived from the recorded rheograms. Using wieners as a model system, the coefficients of variation were determined to be 14.8% for P; 9.7% for E and 8.8% for F. Principles of graphic description of rheograms are presented and the effect of plunger size is demonstrated. Examples are given of the application of the method to meat products and gels used as fat replacements.
INFLUENCE OF THE STARCH GRANULE SURFACE ON THE RHEOLOGICAL BEHAVIOUR OF WHEAT FLOUR DOUGH
Authors: LARSSON HELENA , ELIASSON ANN‐CHARLOTTE
Published: February 2007

The influence of the properties of the starch granule surface on the rheological behaviour of wheat flour doughs was studied in dynamic oscillation measurements (frequency sweep and strain sweep) and in stress relaxation measurements. A flour with a high protein content (15%) was diluted with wheat starch to obtain a protein content of 10%. The granule surface of the substituted starch was modified in three different ways: by heat treatment, by adsorption of a wheat protein fraction and by adsorption of lecithin to the granule surface. The effects of these modified starches were compared with the results obtained for nonmodified starch and protein or lecithin (in liposomes) added to the flour. Owing to the low concentration of the added protein and lecithin, no effect was observed when they were added to the bulk of flour. However, as a starch‐surface modification the same components influenced the rheological parameters studied. Also the heattreated starch had an effect on the rheological behaviour. The study established the importance of the properties of the starch‐granule surface in wheat flour dough.
RHEOLOGICAL PROPERTIES OF ENZYME SUPPLEMENTED DOUGHS
Authors: MARTÍNEZ‐ANAYA M. ANTONIA , JIMÉNEZ TERESA
Published: February 2007

The rheological behaviour of doughs made with different commercial amylases, xylanases, lipases, and glucose‐oxidase, singly and in mixed combinations was investigated. All doughs showed similar trends when subjected to frequency and strain sweep tests. The elastic and viscous moduli increased with frequency, and showed a nonlinear behaviour for strains between 0.2 and 3%. Phase angle presented a maximum at 5 hz in the frequency plot. Resting of doughs decreased complex modulus and increased loss tangent. Enzyme supplementation resulted in softening and weakening of doughs immediately after mixing, and further effects during resting. Pentosan degrading enzymes caused the main changes, and pure lipase preparations the least significant, when compared with unsupplemented doughs. Glucose‐oxidase reduced the softening effect of polysaccharide hydrolysing enzymes.
ON THE tanδ‐FREQUENCY RELATIONSHIP OF FOODS AND AGRICULTURAL COMMODITIES1
Authors: CAMPANELLA OSVALDO H. , PELEG MICHA
Published: February 2007

Published discrete relaxation times spectra of agar and alginate gels, alfalfa, apple and potato flesh, meat, cheese and wheat dough were used to calculate the frequency or frequencies where the phase angle δ(ω vs frequency, ω, relationship peaks. This was done by solving, numerically, the equation dtanδ(ω)/dω= O where d2tanδ(ω)/dω < O, with tanδ(ω) being an algebraic expression derived from the discrete Maxwell model of stress relaxation. The ωpeak of the materials examined was in the range of 10−3 to 10−1 Hz band, setting a lower limit to the frequencies at which such materials can be compared by dynamic tests. This also indicates that the plot of tanδ(ω) vs ω in linear or logarithmic coordinates must have a negative slope at any frequency range above about 0.5 Hz. The frequency at which the peak appears, ωpeak, is primarily determined by the relative weight of the elastic component and the elements of long relaxation times. The higher it is the lower ωpeak is. Thus, the latter can serve as a measure of solidity, inherent to the material or caused by external conditions or through a textural modijication.
DIRECT MEASUREMENT OF BITING PRESSURES FOR CRACKERS USING A MULTIPLE‐POINT SHEET SENSOR
Authors: KOHYAMA KAORU , NISHI MIDORI
Published: February 2007

A multiple‐point sheet sensor was used to observe the distribution of surface pressure during the biting of crackers adjusted to various water activities. The textural characteristics were clearly reflected in the three‐dimensional displays so obtained. Textural differences between samples were most evident in the first 0.3 s. The magnitude, position and duration of biting pressure varied among subjects. For all subjects, crisp crackers with low water activities showed a large pressure distribution with respect to both time and position. Samples with high water activities displayed a higher maximum force on the area under the incisors than samples with low water activities, and required more work per incision. These results are opposite to the rheometric data measured with a single‐point sensor. Using this method, we could directly display textural differences due to the mechanical and geometrical properties of food, and could evaluate their changes in the oral cavity during biting.
A DEVICE FOR EVALUATING MELT/FLOW CHARACTERISTICS OF CHEESES
Authors: WANG Y.‐C. , MUTHUKUMARAPPAN K. , AK M.M. , GUNASEKARAN S.
Published: February 2007

A device to objectively measure the melt/flow behavior of cheeses at different temperatures was built consisting of a temperature‐controlled heater, an LVDT (linear variable differential transformer), and a personal computer with a data acquisition system. This device, named UW Meltmeter, operates in the lubricated squeeze‐flow configuration and can be used either alone at a constant force or in conjunction with a universal testing machine at a constant deformation rate. A marker technique was used to verify the shear‐free squeezing flow assumption. The flow of Mozzarella cheeses with 14 and 43% fat content was studied at 40 and 60C under constant force (0.7 and 0.9 N) and constant cross‐head speed (0.5 and 2.5 cm/min). Biaxial extensional strain rate and biaxial stress growth coefficient were calculated. The results supported the expected trend of increased meltability at higher fat levels and at higher temperatures.
IDENTIFICATION OF KEY TEXTURAL ATTRIBUTES OF ARABIC BREAD AND THEIR APPLICATION TO THE ASSESSMENT OF STORAGE AND QUALITY
Authors: TOUFEILI IMAD , CHAMMAS HABIB , SHADAREVIAN SOSSY
Published: February 2007

Regression analysis of magnitude estimates of 9 manual attributes was utilized to identify the key textural traits of Arabic bread. Twelve samples of Arabic bread were sensorily evaluated for selected textural attributes as perceived by consumers prior to purchasing and during preparation of bread for consumption. The best triplet, average coefficient of determination (R2) of 0.901, for predicting the other textural attributes comprised the force required to initiate tearing, the degree to which the sample extends before rupturing and the pliability of samples. The magnitude of these attributes decreased significantly (p < 0.05) upon storage and exhibited marked variations with differences in quality of Arabic bread. Pliability, resistance to tearing and the degree to which the sample extends before rupturing are adequate for following the rate of staling and for ascertaining differences in quality in this class of baked products.
RHEOLOGICAL PROPERTIES OF CONCENTRATED YOGHURT (LABNEH)
Authors: OZER B.H. , BELL A.E. , GRANDISON A.S. , ROBINSON R.K.
Published: February 2007

The effect of six techniques for the elevation of the total solids on the rheological properties of labneh were investigated using controlled‐stress dynamic rheometer. All samples exhibited a weak viscoelastic gel structure with the storage modulus (G′) higher than the loss modulus (G″) over all of the measured range. None of the experimental materials produced the same overall gel strength as the control made by draining with traditional cloth‐bags. The changes in the storage modulus (G′) as a function of amplitude sweep were mirrored by changes in the loss modulus (G″). Considerable differences in the loss tangent (G”/G′) values of the various materials were observed at higher stress amplitudes. Rheological differences in the overall gel strength at low amplitude and frequency suggest that, although the type of protein interactions in each case may be similar, there are differences in the degree of interactions. Subsequent breakdown at higher amplitudes and frequencies suggests that the overall domains of the treated proteins may have been reduced, and that different methods of manufacture may be producing materials that have different space occupancy in the gel.
EFFECT OF PROCESSING CONDITIONS ON THE COMPOSITION AND RHEOLOGICAL PROPERTIES OF APPLESAUCE
Authors: SCHIJVENS E.P.H.M. , van VLIET T. , van DIJK C.
Published: February 2007

The relation between the composition and rheological properties of applesauce was studied in two ways. For artificial applesauces, reconstituted from isolated applesauce particles and applesauce serum, the residual shear stress increases exponentially with pulp content. Below a particle size of 0.625 mm the values of residual shear stress and apparent viscosity are lower for smaller particles. The effect of the processing conditions (finisher screen openings and cooking time) and raw material (apple variety and ripeness) on particle size and pulp content was studied on sauce made in a pilot plant. The particle size and pulp content of these applesauces affect the rheological properties in the same way as was shown for the artificial applesauces.
TEXTURE AND CHEMICAL FEELING DESCRIPTORS THAT 6–11 YEAR OLDS AND ADULTS ASSOCIATE WITH FOOD IN THE MOUTH
Authors: ORAM NICHOLAS
Published: February 2007

Little is known about children's vocabulary for describing food. The present study investigated the vocabulary for food texture and chemical feelings (e.g., Spicy) of 6 to 11 year olds and adults. Subjects judged if 126 food words (e.g., Chewy), 10 nonfood words (e.g., Jump), and 10 nonwords (e.g., Frunp) were used to talk about food in the mouth. Grade 1 children were interviewed, whereas those in Grades 3 and 5 and adults filled out a questionnaire. The percentage of food‐word judgements was 75% or greater for 13 items in Grade 1, 9 items in Grade 3, 38 items in Grade 5, and 60 items for adults. This vocabulary increases cumulatively with age from Grade 3, words that met the 75% criterion for one age group also did for older ones. At all ages, these words referred to a wide range of attributes. A follow‐up study showed that more Grade 1 children correctly associated Greasy and Tender with hot chips and meat than judged these descriptors to be food‐words. This result implies that descriptors are associated with specific foods before being connected with the label ‘Food'.
EFFECT OF ALKALI AND ALKALI‐EARTH HALIDES ON TEXTURE AND COOKING YIELD OF COOKED COMMINUTED LEAN PORK
Authors: WETTASINGHE M. , SHAHIDI F.
Published: February 2007

The effects of alkali‐and alkali‐earth halides and sulfates on the texture and cooking yield of cooked lean comminuted pork were examined. Divalent cations (Ca2+ and Mg2+) associated with Br−, I− and SO2‐4 imparted a firm texture to meat (peak force values of 17.1–21.1 kg as compared to 8.4 kg for the control sample devoid of any added salt). Peak force values of samples containing monovalent cations were generally low, but for most cases, were higher (P < 0.05) than that of the control. The cooking yields of samples containing divalent cations (regardless of their anion counterparts) were not different (P>0.05) from that of the control. At 200 meq/kg sample, iodides of monovalent cations as well as sodium chloride increased the cooking yield by approximately 5–20% compared to the control.
MRI METHOD TO EVALUATE INTERNAL STRUCTURAL CHANGES OF TOMATO DURING COMPRESSION
Authors: GONZALEZ JUAN J. , McCARTHY KATHRYN L. , McCARTHY MICHAEL J.
Published: February 2007

The effects of compression on the structure of red Roma tomato (Lycopersicon esculentum) were observed using magnetic resonance imaging (MRI). Images were acquired at six strain levels: 0%, 3%, 6%, 20%, 25% and no load sequentially for each of the replicates. The MR images revealed internal structural changes as the strain level increased; these changes were characterized by three displacement parameters: buckling angle (α), flattening angle (β) and columella position (hc). The relative change of these parameters as a function of strain was evaluated by analysis of variance (ANOVA), which showed that the difference in the means was significant at the 0.05 level. In the post hoc analysis, structural changes at the low strains of 3% and 6% were different than the structural changes at the higher strains of 20% and 25%. The columella position showed significant recovery after the load was released. In addition to structural changes, the NMR signal intensity changed as a result of the compression. In particular, signal intensity from the columella region and upper radial arm increased with strain level. However, further studies are required to analyze these changes statistically.
SHEAR RATES DURING ORAL AND NONORAL PERCEPTION OF VISCOSITY OF FLUID FOODS
Authors: HOUSKA M. , VALENTOVA H. , NOVOTNA P. , STROHALM J. , SESTAK J. , POKORNY J.
Published: February 2007

Relationships were established for five sensory methods of oral and nonoral viscosity evaluation between viscosity scores and instrumentally measured dynamic viscosity for model and real Newtonian fluid foods. These relationships were then used to predict the effective shear rates under which the sensory tests were performed. The highest shear rates were predicted for viscosity perception by compression of samples between tongue and palate, and the lowest for pouring the fluid foods from a teaspoon. Mixing with a teaspoon, slurping and swallowing exhibited nearly the same dependencies of apparent shear rates on equivalent instrumental viscosity. All relations were of the hyperbolic type. The resulting relationships between the apprent shear rates and equivalent instrumental viscosity are in good agreement with a similar relationship predicted by Shama and Sherman (1973a) (see Cutler et al. 1983) for oral perception.