bluuebunny/crossref_metadata_2025 huggingface dataset:
FLOW PROPERTIES OF TOMATO CONCENTRATES
Authors: RAO M. A. , BOURNE M. C. , COOLEY H. J.
Published: February 2007

The flow properties of over seventy concentrates made from four cultivars of tomatoes were determined with a concentric cylinder viscometer. The apparent viscosity (100 s−1, 25°C) of the concentrates of each variety was proportional to the 2.5 power of the concentration (% total solids). The apparent viscosity of the Nova cultivar obeyed the Arrhenius temperature relationship; the activation energy for the concentrates was 2.3 ± 0.3 kcal/mole. The simple power law and the Casson model described satisfactorily the flow data of the concentrates but the power law gave higher correlation coefficients. The Herschel‐Bulkley model with the Casson yield stress was also satisfactory but the correlation coefficients were lower than for the simple power law. The consistency index of the power law model also showed a power dependence on the concentration. The natural logarithm of the yield stress and the concentration could be correlated by a quadratic equation.
DETERMINATION OF THE YIELD STRESS OF HYDROCOLLOID DISPERSIONS
Authors: LANG ELIZABETH RO BINSON , RHA CHOKYUN
Published: February 2007

The yield stresses of dispersions of guar gum (0.5–2.0% by weight) and gelatinized cornstarch (2.5–5.0% by weight) were measured using several different established experimental methods. The yield stresses in these polysaccharide dispersions result from intermolecular hydrogen bonding and molecular entanglements, thus the higher yield stress and hysteresis effect in guar gum dispersion was interpreted in terms of the greater hydrogen‐bonding density and molecular entanglements caused by the more extended chain conformation. The results confirm that there is no one absolute value for the yield stress of the hydrocolloid dispersions and that the viscoelastic characteristics of the test materials influence the shear rate and time dependence of yield stress. Therefore, experimental determination of yield stress must be made relevant to the practical application.
EFFECT OF DEGREE OF COMPRESSION ON TEXTURE PROFILE PARAMETERS
Authors: BOURNE MALCOLM C. , COMSTOCK STANLEY H.
Published: February 2007

Texture Profile Analysis (TPA) was performed on apple, carrot, frankfurter, cream cheese and pretzels with the Instron and the effect of the degree of compression on TPA parameters measured at a compression speed of 5 cm/min. Fracturability is almost independent of the degree of compression. Hardness, area 1, area 2, cohesiveness, gumminess, and chewiness usually increase with increasing compression but the rate of increase varies widely. Springiness increases for pretzel sticks and decreases for the four other commodities as compression increases. Adhesive force and adhesive area of cream cheese increase but stringiness decreases with increasing compression. Since the TPA parameters vary so widely with degree of compression, all TPA measurements should standardize the degree of compression and clearly state in reports what compression was used.
EFFECT OF VISCOSITY ON PERCEIVED SWEETNESS INTENSITY OF SWEETENED SODIUM CARBOXYMETHYLCELLULOSE SOLUTIONS
Authors: IZUTSU TADASHI , TANEYA SHIN'ICHI , KIKUCHI EIICHI , SONE TOSHIMARO
Published: February 2007

To establish a relationship between perceived sweetness intensity (Y), sucrose concentration (A%) and viscosity of mixed solutions (B poise), mixtures of sucrose solutions in various concentration and sodium carboxymethylcellulose with medium viscosity (CMC–M) in various concentrations were used, resulting in the equation:
image
where “Y”= sucrose concentration of reference solutions. This equation was effective within the ranges of 4% to 16% sucrose and viscosities of from 1 to 100 poises. This equation was applicable to low and high as well as medium viscosity forms of CMC.
METHOD FOR DETERMINATION OF FIRMNESS IN CUCUMBER SLICES1
Authors: THOMPSON R. L. , FLEMING H. P. , HAMANN D. D. , MONROE R. J.
Published: February 2007

A punch and die assembly was adapted to the Instron UTM for deter‐mination of firmness of mesocarp and endocarp tissues in cucumber slices. A cylindricalpunch 0.315 cm diameter (0.200 to 0.635 cm diameter tested) and a cucumber slice thickness of at least 0.48 cm were found to be suitable for the method developed. Penetration force was about five times greater for mesocarp than endocarp in 4 to 5 cm diameter cucumbers. Mesocarp and endocarp were firmer near the stem end than near the blossom end of cucumbers. Force readings also declined for both tissues with increase in fruit diameter from about 2 to 6 em. Single slices taken from the center of 20 cucumbers and punched once each at specified locations in the mesocarp and endocarp provided sufficient sampling to limit the coefficient of variation to about 5%. The correlation coefficient between sensory analysis for firmness and puncture force readings of fermented cucumber slices was 0.88.
INTERPRETATION OF CONE PENETROMETER CONSISTENCY MEASUREMENTS OF FATS
Authors: HAYAKAWA M. , DEMAN J. M.
Published: February 2007

Cone penetration data were obtained with fats consisting of mixtures of tristearin and olive oil. These mixtures cover a wide range of hardness. The results indicate that consistency of fats measured with a cone penetrometer specified in the AOCS method can be expressed as a hardness index:

HI= Mass of cone assembly/Penetration depth

This simple relationship does not require correction of penetration readings resulting from the use of a truncated cone. 251‐264, Soc. Chem. Ind. London, Monograph 27.
KINETICS OF THERMAL SOFTENING OF VEGETABLES
Authors: HUANG Y.T. , BOURNE M. C.
Published: February 2007

The rate of softening in several canned vegetables during the retort process was studied. The rate of softening is consistent with two simultaneous first order kinetic mechanisms; mechanism 1 acting on substrate “a” and mechanism 2 acting on substrate “b”. The rate constants for mechanism 1 are 20 times or more greater than the rate constantsfor mechanism 2. Approximately 85% to 97% of the firmness of the raw commodity is contributed by substrate “a” and the remaining firmness is contributed by substrate “b”. Mechanism 1 is probably due to pectic changes in the interlamellar layer. The biochemical nature of substrate 2 is a matter of speculation. The apparent Arrhenius activation energies range from 5.1 to 35.0 Kcal/mole. The data indicates that softening kinetics of vegetables is more complex than has been formerly assumed.
COMPARISON OF TWO MODELS FOR FITTING RENNET‐INDUCED MILK COAGULATION KINETICS2
Authors: GERVAIS A. , CERF O.
Published: February 2007

A modified torsiometer (Gervais and Vermeire 1983) was used to determine the coagulation kinetics of raw milk and of milk heated for 14.7 s at temperatures ranging from 105 to 125°C with a direct U.H.T. unit. Two coagulation kinetics models (Scott‐Blair and Burnett 1963; Douillard 1973) were equally satisfactory. From the strict point of view of mathematical adjustment, the two models can be taken as equivalent. In all cases, the residual standard deviation was equal to experimental error.

The Scott‐Blair equation is not suitable since it may give a negative gel time for some heated milks. The authors demonstrate that this is a mathematical artifact, arising from the form of this equation. The Douillard model is best adapted for determining the time at which curd rigidity will reach a given value. The results also show that heating milk modifies its coagulation rate constant, rather than gelling time and maximum rigidity.
TEXTUROMETER AS A TOOL FOR STUDYING VARIETAL DIFFERENCES IN WHEAT FLOUR DOUGHS AND GLUTEN PROTEINS
Authors: RAM B. P. , NIGAM S. N.
Published: February 2007

The General Food's Texturometer has been used for studying the differences in wheat flour doughs prepared from 11 Indian wheat varieties of known gluten composition. The quantities of residue proteins in these varieties and the ratios of residue proteins over gliadins and glutenins were found to show high positive correlation with texturometer hardness and areas of first and second peaks. Adhesiveness was found to show high negative correlations. Of the gluten proteins only glutenins showed varietal differences i.e., the hardness and the areas of the first and the second peaks were found to increase from weak to strong varieties. The gliadins and the residue proteins of the varieties studied were found to be similar. Only gliadins were found to have adhesive character.
AN OBJECTIVE MEASUREMENT FOR EVALUATION OF BIND IN RESTRUCTURED LAMB ROASTS
Authors: FIELD R. A. , WILLIAMS J. C. , PRASAD V. S. , CROSS H. R. , SECRIST J. L. , BREWER M. S.
Published: February 2007

An attachment for the Instron Universal Testing machine for the measurement of bind in restructured lamb roasts is described. Break strength is defined as the force in kg necessary for a polished steel ball to burst through the center of a slice of restructured roast. Elongation is the distance traveled by the ball after contact with the slice surface before the ball bursts through. As level of NaCl increased from 1% to 1.5%, values for bind characteristics increased but 10% or 30% mechanically separated lamb (MSL) did not affect values for bind characteristics. Simple correlations between three adjacent slices for break strength were all above 0.9 but values for elongation were lower (r = 0.6‐0.7).
A COMPUTERIZED SYSTEM FOR THE ACQUISITION AND ANALYSIS OF TIME‐DEPENDENT FLOW DATA
Authors: XU S. Y. , LEWIS J. I. , SHOEMAKER C. F.
Published: February 2007

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EVALUATION OF A SLIDING PIN CONSISTOMETER FOR MEASUREMENT OF THE HARDNESS AND SPREADABILITY OF BUTTER AND MARGARINE
Authors: DAVEY KENNETH R. , JONES PETER N.
Published: February 2007

A sliding pin consistometer (SPC) has been shown to be particularly suitable for the assessment of hardness and spreadability of butter and margarine. It appears advantageous over other methods in that it is portable, self‐compensating for wear, and is convenient and rapid to use on undamaged samples in their original packaging. Four products, hard and soft butter, and hard and soft margarine, with product temperatures in the range 0.8 to 20.0deg;C, were used. The hardness and spreadability of these products at these temperatures were also scored by a panel of 21 adults using a 9‐point scoring scale. SPC measurements explained 96% of the variation in panel scores for both hardness and spreadability. The maximum panel score for spreadability was at an SPC value of 5.5 × 10−2N for all four products. The SPC should prove useful to manufacturers of butter and margarine in assessing consumer preference for their products.
THE RELATIONSHIPS OF PITCH, LOUDNESS AND EATING TECHNIQUE TO JUDGMENTS OF THE CRISPNESS AND CRUNCHINESS OF FOOD SOUNDS2
Authors: VICKERS ZATA M.
Published: February 2007

Twenty subjects judged a variety of tape recorded bite sounds and chew sounds for both crispness and crunchiness. Crispness scores were generally higher for the bite sounds than for the chew sounds. Crunchiness judgments showed no overall difference between bites and chews. However, the interaction between the eating technique and the individual food sounds was highly significant for both crispness and crunchiness judgments, and in several cases the result for a specific food differed from the general conclusions.

From the results of the first test, two subsets of the sounds were selected based on significant t‐tests: one set in which the sounds were either more crisp than crunchy or more crunchy than crisp, and a second set in which the bite and chew sounds for the same product differed in crispness. These subsets were tested twice by a second group of twenty subjects to determine whether the differences might be related to loudness or pitch. The crisper sounds were typically both higher in pitch and louder than the crunchier sounds although exceptions occurred. In the majority of bite versus chew pairs, the crisper sounds were also louder‐ and/or higher‐pitched than the less crisp sounds.
CHARACTERIZATION OF LINEAR AND NONLINEAR DEFORMATION BEHAVIOR OF A WEAK STANDARD GEL MADE FROM HIGH‐METHOXYL CITRUS PECTIN
Authors: DAHME A.
Published: February 2007

A physical characterization of the deformation behavior up to the gel fracture is given for a weak pectin‐saccharose‐water standard gel from high‐methoxyl citrus pectin. The results refer to citrus pectin from different commercial sources and also to high‐methoxyl apple pectin.
INFLUENCE OF NUMBER AND THICKNESS OF BLADES ON THE PERFORMANCE OF THE KRAMER TYPE SHEAR‐COMPRESSION CELL2
Authors: TIMBERS G. E. , VOISEY P. W. , KLOEK M.
Published: February 2007

A study was undertaken to determine the influence of number of blades and their thickness on the performance of the Kramer type shear compression cell Cells with 4, 6, 8, 10 and 12 blades, with corresponding blade thicknesses ranging from 6.4 to 0.4 mm, were manufactured and compared against a standard Kramer shear cell Seven canned vegetables were used in the trials. Maximum force, bio‐yield force, firmness and energy to maximum force were recorded and compared in testing these products in the different cell configurations. Very thin blades proved to be a source of mechanical problems when used with firm products and will not be used in any further studies. Readings obtained with the various cell configurations were product dependent and forces with the standard cell were higher. Blade spacing is a critical factor in the cell design.
VISCOELASTIC BEHAVIOUR DURING THE GELATINIZATION OF STARCH I. COMPARISON OF WHEAT, MAIZE, POTATO and WAXY‐BARLEY STARCHES
Authors: ELIASSON A.‐C.
Published: February 2007

Dynamic measurements were used to characterize the viscoelastic behavior during gelatinization of wheat, maize, potato and waxy‐barley starches. During the experimental conditions used the curves of storage modulus (G′) and loss modulus (G″) versus temperature showed an initial peak for all starches, followed by a second peak at 90–95° C in the case of wheat and maize starches. Wheat starch gave a more viscous response than the other starches. The changes in G′ and G″ were correlated to the changes in gel volume and amylose leaching during the heating. The results were interpreted using a composite material as a model for the starch gel.
SENSORY AND MECHANICAL ATTRIBUTES OF GEL TEXTURE
Authors: MUÑTOZ ALEJANDRA M. , PANGBORN ROSE MARIE , NOBLE ANN C.
Published: February 2007

Eighteen experienced judges evaluated the texture of gels varying in gelatin concentration (22‐45 g/L) in terms of firmness by oral and manual shear and compression, cohesiveness, and extent of breakdown in the mouth. Manual compression and biting with the front teeth discriminated well across gel concentrations. All sensory measures except extent of breakdown increased with gelatin concentration. Instron (IUTM) measurements showed that increasing gelatin concentration resulted in an increase in maximum force and force/deformation, but had little effect on deformation at yield and rupture or in elasticity and cohesiveness. Results from mechanical measurements varied with the type of force applied (compression, shear or puncture), the loading rate (50 or 200 mm/min), and the extent of deformation attained (40–90%). The highest discrimination across gel concentrations was achieved with shear force at a rate of 200 mm/min and at greater deformations. Sensory responses correlated most highly with the following IUTM measurements: (1) Compression forces at yield and at deformations of 70 and 85% at the higher crosshead speed; (2) Compression forces below the yield point at the lower crosshead speed; and (3) Shear forces measured at maximum deformation (90%) at 200 mm/min.
AQUEOUS DISPERSION RHEOLOGY OF EXTRUSION COOKED MAIZE
Authors: BRENNER P. E. , RICHMOND P. , SMITH A. C.
Published: February 2007

The effects of twin screw extrusion cooking of maize grits at different high moisture contents are described. Starch granules survive in the extrudate at high extrusion moisture or with a low shear screw configuration. The aqueous dispersion rheology of the milled extrudate and its dependence on shear rate and heat treatment is explained in terms of the starch swelling behaviour and solubility. These data resemble that of raw maize most closely for the low shear screw configuration. For the high shear configuration under similar conditions of moisture, temperature and mechanical energy dissipation, starch granules are not seen and the dispersion rheology is markedly different from that of raw maize.
TEXTURAL PROPERTIES OF COOKED TROPICAL YAM (DIOSCOREA SPP
Authors: ONAYEMI O. , BABALOLA R. O. , BADANGA A.
Published: February 2007

Three yam species, white yam (Dioscorea rotundata), yellow yam (D. cayenensis) and water yam (D. alata), were evaluated for textural characteristics. Differences in the texture of the yam varied with species, section of the yam used and the length of storage following harvest. Differences in texture were related to changes in the starch granules upon cooking. Compressive strength of the cooked disks correlates with the amount of starch released during cooking. The modified sensory texture profile analysis, however, is more descriptive of the textural characteristics of the cooked yams and emphasises those attributes which can be measured objectively. Freshly harvested yams had lower intensity ratings for the main textural attributes than stored yams. The possibility of using some yam varieties and sections of them as products with special textural qualities is suggested.
FLOW BEHAVIOUR OF TOMATO KETCHUPS
Authors: RANI UPASANA , BAINS G.S.
Published: February 2007

The flow behaviour of 13 tomato ketchups was characterized using a coaxial cylinder viscosimeter. Power law values for the flow behaviour index n averaged 0.35 ± 0.016 which indicated the pseudoplastic nature of ketchups. The consistency coefficient K values for ketchups depended more on temperature, pectin and pulp contents than on total solids. Activation energy (Ea) values for flow of ketchups varied from 1.99 to 4.88 kcal/mole and were significantly related with pectin contents. The Casson's yield values for ketchups showed a significant correlation with pectin contents. Michaels and Bolger model parameters showed that much greater forces were involved in the breaking of network structure and aggregates in ketchups than needed for flow. Multiple regressions of K and apparent viscosity on pectin and pulp contents of ketchups were highly significant.
FAT CRYSTAL NETWORKS: STRUCTURE AND RHEOLOGICAL PROPERTIES
Authors: DEMAN J. M. , BEERS A. M.
Published: February 2007

The solid character of plastic fats is the result of the presence of a certain percentage of crystallized fat. Although methods are now available to measure solid/liquid ratios without difficulty, there is no conclusive theory which will relate crystal size and shape, solid fat content and rheological properties. It is generally assumed that plastic fats contain a three‐dimensional network of fat crystals, held together by primary (nonreversible) and secondary (reversible) bonds. This paper highlights the hypotheses that have been put forward concerning the forces existing between fat crystals, the rheological properties of plastic fats, and recent information on crystal network structure.
NONENZYMATIC LIGNIFICATION OF ASPARAGUS?
Authors: SMITH J. L. , STANLEY D. W. , BAKER K. W.
Published: February 2007

The hypothesis of nonenzymatic lignification was investigated in asparagus. Samples were stored within 2 h of harvesting at 22C, 4C and ‐ IOC and tested daily, every second day and at 30‐day intervals, respectively. Some asparagus was blanched at IOOC for 3 min prior to storage. Assays for peroxiduse and polyphenoloxidase showed no enzymatic activity in the blanched samples. Toughness, as measured by Warner‐Bratzler shear force, and crude fiber content (mechanically separated) significantly (P< 0.05) increased in both blanched and unblanched samples over the testing period at all storage conditions. Crude fiber content and shear measurements were significantly (P < 0.05) higher for the enzyme active controls. Microscopic examinations using light (LM) and scanning electron microscopy (SEM) were canied out to locate the site of lignin deposition and to quantify the extent of lignification. Sections viewed using LM techniques were stained to observe useful fluorescence (crystal violet ‐ erythrosin B) and differentiate ligniped from nonlignified cell walls fast green safranin and crystal violet ‐ ertythrosin 8). In samplesfrom each treatment and storage condition, three independent techniques indicated a significant (P < 0.05) increase in: (1) the width of the mechanical tissue layer; (2) the thickness of the cell walls of the cells comprising the mechanical tissue layer, and; (3) the thickness of the xylem vessel walls of the vascular bundles. Also, significant (P C 0.05) differences were detected between the extent of lignification of unblanched and blanched samples. These data suggest that a nonenzymatic “toughening” mechanism does occur in blanched asparagus tissue and that it may be related to lignin deposition.
INFLUENCE OF SURFACE FRICTION ON THE STRESS RELAXATION OF GOUDA CHEESE1
Authors: GOH H. C. , SHERMAN P.
Published: February 2007

The stress relaxation behaviour of Gouda cheese cylinders with a diameter/length ratio of 0.7 was studied at compression rates of 5 and 100 cm min‐1. Tests were made in three ways: (1) normal test procedure i. e., the samples were not lubricated, (2) with the samples' upper and lower ends lubricated with mineral oil, (3) with emery paper inserted between the samples and the compression plates so as to exaggerate the friction effects. Surface friction affected stress relaxation behaviour using the normal and emery paper test procedures at compressions up to about 20%. At higher concentrations cracks are initiated and propagated in all three test procedures. The values of the rheological parameters derived from relaxation data obtained using compressions not exceeding 20% were lower for lubricated samples. This is attributed to the elimination of that component of the initially applied force which was required to overcome surface friction and which does not decay with time, in contrast to the component actually involved in the initial compression which exhibits stress relaxation.
A MULTICHANNEL, COMPUTER‐BASED SYSTEM FOR ANALYZING DOUGH RHEOLOGY 1
Authors: PON C. R. , LUKOW O. M. , BUCKLEY D. J.
Published: February 2007

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METHOD FOR DETERMINING ABSOLUTE SHEAR MODULUS OF GELS FROM COMPRESSION TESTS
Authors: OAKENFULL D. G. , PARKER N. S. , TANNER R. I.
Published: February 2007

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EFFECTS OF WATER, OIL, EGG WHITE AND STARCH ON THE TEXTURE OF COD SURIMI GELS BY RESPONSE SURFACE METHODOLOGY
Authors: HASTINGS R. J. , CURRALL J. E. P.
Published: February 2007

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INSTRUMENTAL MEASURES OF CRISPNESS AND THEIR CORRELATION WITH SENSORY ASSESSMENT
Authors: VICKERS Z. M.
Published: February 2007

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CRISPNESS AND CRUNCHINESS OF SELECTED LOW MOISTURE FOODS1
Authors: SEYMOUR S. K. , ANN D. D. HAM
Published: February 2007

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RHEOLOGICAL CHARACTERIZATION OF COMMERCIALLY PROCESSED FLUID MILKS
Authors: WAYNE JO ELLEN B. , SHOEMAKER CHARLES F.
Published: February 2007

Flow profiles of commercially processed whole, two‐percent, one‐percent and nonfat milks with added solids as well as skim milk without added solids were measured using a rotational steady shear viscometer. Also tested were mixtures of concentrated skim milk added to skim milk over a range of 9.7% to 20.2% total solids. A shear rate range of 121 to 486 s‐1 was used with a cone and plate geometry. In all cases, linear plots of shear stress versus shear rate with small nonzero intercepts were obtained.
A COMPUTERIZED METHOD TO ANALYZE THE CREEP BEHAVIOR OF VISCOELASTIC FOODS
Authors: BALABAN M. , CARRILLO A. R. , KOKINI J. L.
Published: February 2007

A computer‐aided method was developed to simplify the analysis of creep behavior and to determine the elasticity, the Newtonian viscosity and individual viscosities of viscoelastic foods. The method enabled the inclusion of all creep compliance data in the analysis, and reduced the analysis time from hours to minutes. The method was tested in the calculation of rheological properties of wheat flour dough.
SELECTED PHYSICAL AND MECHANICAL PROPERTIES OF COMMERCIAL APPLE CULTIVARS1
Authors: REBOUILLAT S. , PELEG M.
Published: February 2007

The compressive modulus of deforatability, strength and strain of failure of apple flesh of 12 commercial apple cultivars were determined using a Universal Testing Machine. The deformability modulus, calculated from the linear part of the corrected stress‐Hencky's strain relationship was between 1.5 to 2.3 MPa with a coefficient of variation of 9–26%. The apparent upper limit of the strain in the linear region was on the order of 0.08–0.2. The compressive strength was on the order of 160–280 kPa, with the Baldwin apples a notable exception with strength twice as large. Failure usually occurred at a strain of 0.12–0.16 with the exception of the Baldwin and Granny Smith apples for which failure occurred at a strain of 0.25 and 0.2, respectively. The variability in the failure parameters
Sensory Perception of Foods. 2nd edition (J.R. Piggott, ed.), Elsevier Science Publishers, London. 1988. 406 pp. £56.
Authors: SHERMAN P. , BOURNE MALCOLM C.
Published: February 2007

Sensory Perception of Foods. 2nd edition (J.R. Piggott, ed.), Elsevier Science Publishers, London. 1988. 406 pp. 256.

Food Structure ‐ Its Creation and Evaluation. (J.M.V. Blanshard and J.R. Mitchell, eds.) Butterworths, London. 1988. 504 pages. $225.
RHEOLOGICAL CHARACTERIZATION OF SALAD DRESSINGS 2: EFFECT OF STORAGE
Authors: PAREDES M.D.C. , RAO M. A. , BOURNE M. C.
Published: February 2007

The consistency index and the flow behavior index of the power law model, and yield stress according to the Casson model that describe the viscoelastic nature of a model salad dressing were determined as a function of storage time and temperature. A four parameter model was employed to describe the creep‐compliance data. Major changes in the magnitudes of the rheological parameters took place during the initial seven days of storage. The changes are attributed to coalescence of oil droplets and to hydration of the food gum. Creep‐compliance data on six commercial salad dressings showed significant differences in the rheological behavior among the dressings.
ANALYSIS OF SURIMI GEL PROPERTIES BY COMPRESSION AND PENETRATION TESTS
Authors: LEE CHONG M. , CHUNG KANG H.
Published: February 2007

Gel properties of surimi of different quality were analyzed using compression and penetration tests. Parameters used to vary the surimi quality were species, freshness, freeze‐abuse and added ingredients. Compressive force at failure was more discriminative than penetration force. The result of a failure response analysis suggests that the compression test is useful in assessing the cohesive property, while the penetration test is better for assessing density and compactness. Good correlations between compression and penetration force values were seen in surimi gels prepared from the same species with and without ingredients, while poor correlations were observed in the surimi which either underwent freeze‐abuse or was prepared from different species.
EFFECTS OF TEMPERATURE AND MOISTURE CONTENT ON THE VISCOELASTIC BEHAVIOR OF COWPEAS
Authors: PAPPAS G. , RAO V. N. M.
Published: February 2007

The viscoelastic parameters of cowpeas (Vigna unguiculata) were studied at different temperature and moisture content combinations. Cowpeas were tested at temperatures of 25°, 45° and 70°C and moisture contents of 13.9, 19.6 and 22.4% dry basis on an Instron Universal Testing Machine using stress relaxation techniques. The response of cowpeas was characterized by two Maxwell bodies in parallel without the incorporation of a residual spring. The relaxation curves (uniaxial modulus versus time) were used to calculate temperature and moisture shift factors, which subsequently led to the construction of a single master response curve. Cowpeas are both thermo‐rheologically and hydro‐rheologically simple biological materials.
RHEOLOGICAL AND INTERFACIAL BEHAVIOUR OF SOME WHEAT PROTEIN FRACTIONS 1
Authors: ELIASSON A.‐C. , LUNDH G.
Published: February 2007

Gluten from the wheat variety Monopol was fractionated by successive extractions with dilute HCl (0.625–1.5 mM). The first two fractions, obtained at the highest pH values, contained a high proportion of low molecular weight proteins, they spread quickly at the air/water interface and when added to a wheat flour dough they increased the phase angle of the dough. The three following fractions contained a high proportion of high molecular weight proteins, they spread very slowly at the air/water interface and they caused the wheat flour dough to become stiffer (the storage modulus increased) and more elastic (the phase angle δ decreased). The last fractions obtained in amounts enough for investigation were in between the other fractions in the molecular weight distribution and interfacial behaviour, and they hardly affected the rheological properties of the dough.
REVERSIBLE GELATION OF WHEY PROTEINS: MELTING, THERMODYNAMICS AND VISCOELASTIC BEHAVIOR
Authors: RECTOR D. J. , KELLA N. K. , KINSELLA J. E.
Published: February 2007

Whey protein isolates formed reversible gels following heating at 90°C for 15 min under certain conditions i.e., pH 6.5 to 8.5 with protein concentration of 9.0–10.5%. The melting temperatures of the gels formed at pH 8.0 ranged from 24.5°C to 57.8°C. The maximum enthalpy of formation (ΔHf) was –858 call mole of crosslinks. A maximum storage modulus (G') of 240 dynes/cm2 was obtained following holding for 7 h at 8°C.
STRUCTURAL AND CHEMICAL BASES FOR TEXTURE OF PLANT FOODSTUFFS
Authors: ILKER REINFRIEDE , SZCZESNIAK ALINA S.
Published: February 2007

Following a brief review of plant morphology, tissue organization and cell structure, the structure/texture relationship in edible plant materials is discussed with special emphasis on the role of cell wall and cytoplasmic components (starch, protein, lipids and vacuolar solutes). The review of published experimental data is supplemented with information deducible from interfacing the disciplines of plant physiology/microscopy and food science/texture. Recent engineering studies on tissue failure are discussed and their relevance to the advancement of the structure/texture relationship is pointed out.
RELAXATION STUDIES OF ACID TYPE CHEESE TEXTURE BY A CONSTANT SPEED CONE PENETROMETRIC METHOD
Authors: KOROLCZUK J. , MAHAUT M.
Published: February 2007

A constant speed cone penetrometer (Stevens, UK) connected to a microcomputer (Amstrad CPC 6128, UK) was used to analyse the tangential stress during penetration and the stress relaxation after the penetration had stopped. For acid cheese samples containing between 12 and 39% of total solids the tangential stress was between 0.3 and 14 kPa. Stress relaxation was best reproduced (coefficient of variation CV = 0.6%) by the Avrami (1939, 1940, 1941) and Nutting (1921) equations (CV = 1.4%). Using the models of Peleg (1979) and Maxwell (1868) the fit was much worse (CV = 4.9% and 9.5% respectively). Nonrelaxing stress represented 10 to 30% of the initial stress level.
ANALYSIS OF FOOD CRUSHING SOUNDS DURING MASTICATION: TOTAL SOUND LEVEL STUDIES 1
Authors: III W. E. LEE , SCHWEITZER M. A. , MORGAN G. M. , SHEPHERD D. C.
Published: February 2007

The total sound level of airborne noise was measured continuously during consecutive chews of fresh and stale samples of potato chips and tortilla chips. Sensory estimations of crispness were also made. Samples were evaluated using both an open mouth and a closed mouth procedure. Analysis showed that the total sound level decreased as chewing progressed. Significant differences were observed between open mouth and closed mouth chewing, with the former displaying higher sound levels. However, there were no statistical differences in the sound levels between fresh and stale samples. Sensory assessments ofcrispness showed decreasing crispness as chewing progressed. Statistical differences were observed in the sensory evaluations between fresh and stale samples. Openmouth sensory evaluations were significantly different from closed‐mouth evaluations for potato chips but not for tortilla chips. Good correlations were observed between the acoustic measurements and the sensory estimations, in agreement with the work of other investigators.
FLOW PROPERTIES OF BABACO (CARICA PENTAGONA) PUREES AND CONCENTRATES
Authors: CASTALDO D. , PALMIERI L. , VOI A. LO , COSTABILE P.
Published: February 2007

A power law model describes adequately the rheological behaviour of Babaco purees and concentrates while a Herschel‐Bulkley model describes concentrates only. A single equation ηa=α x cβ x exp (Ea/RT), combining the effects of temperature and concentration on apparent viscosity (ηa100), was used to describe rheological behaviour.
THE VISCOSITY OF SUPERCOOLED FRUCTOSE AND ITS GLASS TRANSITION TEMPERATURE
Authors: OLLETT A.‐L. , PARKER R.
Published: February 2007

The viscosities of supercooled liquid fructose and glucose are measured between a lower viscosity limit corresponding to 95°C and an upper limit of about 106 Pa.s. The glass transition temperature of fructose is estimated from the viscosity data using different extrapolation procedures. The Vogel‐Tamman‐Fulcher and power‐law equations gave estimates of 283K and 289K, respectively and the Williams‐Landel‐Ferry equation 286K. These values are in agreement with recent calorimetric determinations of the glass transition temperature.
TRACKING FOODSTUFF LOCATION WITHIN THE MOUTH IN REAL TIME: A SENSORY METHOD1
Authors: LEE III W. E. , CAMPS M. A.
Published: February 2007

A computer‐based procedure has been developed which allows the tracking of the location of food samples within the mouth in real time. The BASIC program presents an outline of a human upper jaw on a monitor screen which also indicates the approximate location of cheek inner surfaces. Subjects use a mouse to move a cursor on the screen to indicate their assessment of where the sample is located within the mouth at any point in time. Data is stored in an array of the form: (x position, y position, time). Program output displays the data in the form of a “trail.” This procedure was used to study a variety of food samples including beverages, salted snacks, and candies. While not absolutely quantitative, the oral patterns can suggest what activities may be dominating at any point in time such as molar or tongue compression. This procedure can be used with other sensory textural profiling techniques to possibly yield a more complete understanding of the textural response.
THE INFLUENCE OF FAT, ACID, AND SALT ON THE PERCEPTION OF SELECTED TASTE AND TEXTURE ATTRIBUTES OF CHEESE ANALOGS: A SCALAR STUDY
Authors: STAMPANONI CHANTAL R. , NOBLE A. C.
Published: February 2007

Twelve cheese analogs varying in amounts of fat (10 17.5, and 25%), sodium chloride (0.5 and 2.0%), and citric acid (0.1 and 1.2%) were prepared to determine the influence of the three constituents on taste and texture perception, as well as on the rheological behavior of the analogs. Sourness, saltiness, springiness, firmness, cohesiveness, and adhesiveness were rated by trained judges on a graphic scale. The Instron Universal Testing Machine was used for the rheological studies. Increasing the salt content in the cheese analogs resulted in an increased saltiness and sourness intensity and a decreased pH. Increasing the acid or salt content caused a significant decrease in cohesiveness and springiness and an increase in firmness. A higher fat content resulted in a softer, less springy, more cohesive and adhesive cheese analog.
MODELLING THE GELLING BEHAVIOUR OF LINSEED POLYSACCHARIDE
Authors: SUSHEELAMMA N. S. , CHAND NAGIN , RAJALAKSHMI D.
Published: February 2007

The gelling behaviour of linseed polysaccharide was measured in the presence of sucrose as a function of both polysaccharide and sucrose concentrations. Yield stress, consistency index, and flow behaviour index were determined using the Herschel‐Bulkley model. Transition concentrations of 0.7% for the polysaccharide and 55% for sucrose were found. Yield stress and consistency index increased with both polysaccharide and sucrose concentrations while flow behaviour index decreased. A polynomial model of the third degree on centred data after natural log transformation was found to give a satisfactory fit for the variations in rheological constants. The models for both yield stress and consistency index were a complex power law, and for flow behaviour index a complex semi‐log relationship, on sucrose and polysaccharide concentrations.
SYMMETRIZED DOT‐PATTERNS (SDP) OF IRREGULAR COMPRESSIVE STRESS‐STRAIN RELATIONSHIPS 1
Authors: PELEG M. , NORMAND M.D.
Published: February 2007

Symmetrized dot‐pattern displays (SDP) of the kind used in speech analysis and medical diagnosis can also be used to visualize textural differences between and among crunchy foods. Meaningful interpretation of the patterns in terms of textural characteristics, however, will require further study of two topics: how the display parameters, notably the number of points and symmetry axes affect the resulting image perception, and how factors such as the specimen's geometry and moisture content, for example, affect the pattern's morphological features.
EFFECT OF SAMPLE DIMENSIONS AND DEFORMATION RATE ON THE TORSIONAL FAILURE OF DUMBBELL SHAPED GELS
Authors: MIRZA IQBAL , LELIEVRE JOHN
Published: February 2007

Torsional failure measurements were made on gels with dumbbell and capstan geometries. As a comparison, cylindrical specimens were tested in uniaxial compression. Both brittle and elastic gels, made from carrageenan and locust bean gelling agents by selecting appropriate ratios of the two polymers, were investigated. Using the dumbbell geometry, the stress at failure was found to be independent of the sample dimensions while the failure strain decreased with increase in the aspect ratio. In addition, neither the stress nor the strain at failure depended on the strain rate. The failure parameters from the two torsion geometries and the compression test were found to agree provided comparison was made using appropriate sample dimensions.
RHEOLOGICAL PROPERTIES OF WHEY PROTEIN ISOLATE GELS DETERMINED BY TORSIONAL FRACTURE AND STRESS RELAXATION 1
Authors: FOEGEDING E. ALLEN
Published: February 2007

The effect of protein concentration on the rheological properties of whey protein isolate gels was investigated. Torsional fracture analysis was used to determine true shear stress and true shear strain at fracture, and initial Young's modulus (Eo) and equilibrium Young's modulus (Ee) were determined by stress relaxation. The power law equation provides an accurate description for the effect of protein concentration on shear stress at fracture and Eo and Ee moduli. The strain at fracture initially decreased with protein concentration and remained constant after a critical concentration was achieved. This trend was similar to relaxation time determined at nonfracture strains, establishing an association between strain at fracture and viscoelastic properties of whey protein isolate gels.
FLOW PROPERTIES OF STIRRED YOGHURT: STRUCTURAL PARAMETER APPROACH IN DESCRIBING TIME‐DEPENDENCY
Authors: BENEZECH T. , MAINGONNAT J.F.
Published: February 2007

The time dependent rheological behaviour of 4 commercial stirred yoghurts was evaluated at constant shear rate within the range 18 to 280 s‐1.

The viscosity decreased greatly to an equilibrium value after 600 s of shearing. A simple model based on a structural approach was used. A rheological test was designed and carried out at a constant shear rate of 111 s‐1 and a temperature of 10C. Three types of stirred yoghurt processed in the laboratory under standard conditions were compared with the 4 commercial brands. Two parameters of the model were highly significant for comparing the different stirred yoghurts. These were the rate constant of the structural decay and the consistency index at equilibrium.
A CONSTITUTIVE RELATIONSHIP FOR GELS UNDER LARGE COMPRESSIVE DEFORMATION
Authors: GAO Y.C. , LELIEVRE J. , TANG J.
Published: February 2007

A three‐parameter constitutive relationship was developed based on a strain energy function to describe the mechanical behaviour of gels subjected to large deformation under compressive load. The parameters in the relationship can be estimated from experimental data using regression techniques. Alternatively, these unknowns may be determined directly from three compression parameters σm, ɛm, β, which represent the strength, ductility and nonlinearity of the mechanical behaviour, respectively. The new constitutive relationship fits experimental data, for both brittle and ductile gels, up to the point of compressive failure.
INSTRUMENT FOR MEASURING BIND STRENGTH OF RESTRUCTURED AND EMULSION‐TYPE MEAT PRODUCTS1
Authors: DOBSON B.N. , MOISEEV I.V. , CORNFORTH D.P. , SAVELLO P. , WOOD R.J. , ANDERSEN R.
Published: February 2007

A sensitive and inexpensive penetrometer is described, consisting of a mounted rod and polished steel ball that may be advanced downward at variable speed through meat slices mounted on a plexiglass cylinder. The slice + mounting cylinder was placed on a top‐loading balance, tared to zero, and centered under the penetrometer rod. Bind strength was measured as the peak force (g) required for the steel ball advancing at 2.0 cm/min to penetrate the meat slice. Data points (grams force versus time) were collected and plotted using an IBM‐compatible personal computer and printer. Since the balance collected gram values continuously, a QuickBasic program was developed, allowing the user to specify the time interval (1,2,5 s, etc.) between recorded values. Bind strength of turkey rolls was increased by finely chopping the emulsion (vs. coarsely‐ground samples), and by inclusion of 3% nonfat dry milk. Whey protein concentrate (3%) increased bind strength of finely chopped, but not coarsely ground rolls.
METHOD TO INVESTIGATE DIFFERENCES IN CHEWING BEHAVIOUR IN HUMANS
Authors: BROWN WENDY E.
Published: February 2007

This study examines whether the patterns of muscle activity measured from the masticatory muscles during a chew are sufficiently reproducible to form the basis of a characterisation of chewing behaviour, and whether they express the degree of variation evident between individuals. Electromyograph (EMG) readings of the repetitive activity involved in chewing gum were analyzed for 10 subjects, each on three separate occasions. For each individual the temporal aspects of the chew cycle (duration of the activity burst, period between bursts of activity and duration of the complete cycle) were reproducible between EMG recording sessions. Consistency was also found for amplitude aspects of the EMG record: mean voltage within the activity burst, maximum voltage, and the area under the EMG trace. For all six parameters there was significant variation between subjects. The study showed that variations in the chewing pattern, as occur for chewing on opposite sides of the mouth, were reflected in the 6 EMG parameters examined, and that the changes elicited were different for each individual. Moreover, encouraging subjects to concentrate on the act of chewing caused them to modify their chewing pattern, highlighting the importance of avoiding such attention when assessing habitual chewing behaviour.
METHOD TO INVESTIGATE DIFFERENCES IN CHEWING BEHAVIOUR IN HUMANS
Authors: BROWN WENDY E. , SHEARN MARK , MacFIE HALLIDAY J. H.
Published: February 2007

This study develops a method to describe chewing behaviour, for individual subjects, based on data obtained from electromyograms recorded from the temporalis and masseter muscles during consumption of selected food samples. The data include measurements of the duration of the chewing sequence, the chew rate, the chewing work performed and its apportionment within the chewing sequence, manipulation of the bolus and swallowing. The numerical description of chewing behaviour obtained was shown to be consistent for each subject over separate recording sessions and expressed differences between subjects.
A MATHEMATICAL MODEL OF CRUNCHINESS/CRISPNESS LOSS IN BREAKFAST CEREALS1
Authors: PELEG MICHA
Published: February 2007

Published sigmoid relationships between sensory crunchiness/crispness scores of five breakfast cereals and water activity (Sauvageot and Blond 1991) were fitted with the model Y(aw) = Yo/{1 + exp [aw ‐ awc)/b]}, where Y(aw) is the sensory score at a given aw level, Yo the score of the cereal at the dry (glassy) state, awc a critical water activity representing the inflection point of Y(aw) and b a constant representing the steepness of Y(aw) in the aw region where much of the plasticization occurs. In all five cases the fit of the model, which had previously been used with instrumental mechanical parameters of stiffness and crunchiness, was almost perfect (r2 in the range of 0.997–0.999). All the cereals had similar Yo and awc values, Yo between 7.5 and 7.9, on a scale of 10, and awc between 0.62 and 0.68. The range of water activity in which most of the perceived crunchiness/crispness loss took place, however, varied considerably among the five cereals, with the constant b being in the range of 0.046–0.093. Since according to this model about 90% of the perceived crunchiness/crispness loss occurs within awc± 3b these numbers correspond to water activity spans between about 0.28 and 0.55, respectively.
INTERRELATIONSHIPS BETWEEN SENSORY AND MECHANICAL CHARACTERISTICS OF CANNED PEACHES
Authors: APOSTOLOPOULOS C. , BRENNAN J. G.
Published: February 2007

The 37 sensory characteristics of commercially canned peaches were measured using Quantitative Descriptive Analysis. Some mechanical parameters of the fruit were also measured by using both empirical and fundamental instrumental tests. Principal Component Analysis was employed to study the intra‐ and interrelationships of the sensory and the mechanical characteristics of the canned peaches. The results indicated that most of the characteristics were grouped in four main clusters. These clusters defined two perceptual axes corresponding to the first two principal components which described 76% of the variation. The first component described the viscoelasticity and the second the pleasantness of the sensory characteristics. It was also shown that the mechanical parameters of the fruits were good predictors of the whole range of their textural characteristics.
GRAVITY CURRENT ANALYSIS OF THE BOSTWICK CONSISTOMETER FOR POWER LAW FOODS
Authors: MCCARTHY KATHRYN L. , SEYMOUR JOSEPH D.
Published: February 2007

Flow observed in the Bostwick consistometer was evaluated as a gravity current; the balance of forces yields the Bostwick measurement as a function of the geometry of the apparatus and fluid properties. Experimental measurements for Newtonian and power law fluids are compared to theoretical predictions. Although the theory can be used to evaluate values for power law parameters, the best results are obtained by predicting the ratio of apparent viscosity to density to the –0.2 power. The agreement between theory and experiment for homogeneous fluids is within 2%. Values of Bostwick measurement versus (η/ρ)−0.2 for tomato suspensions fall along the same curve as the homogeneous fluids.
YIELD STRESS OF FOOD DISPERSIONS WITH THE VANE METHOD AT CONTROLLED SHEAR RATE AND SHEAR STRESS
Authors: YOO B. , RAO M. A. , STEFFE J. F.
Published: February 2007

The vane method was used to measure yield stresses of 15 commercial food dispersions under controlled shear stress (Cσ) and controlled shear rate (C) operating conditions. Magnitudes of yield stress (σσ) at Cσ were higher than those of yield stress (σ) at C on tomato products and baby foods. There were good linear correlations (R2= 0.96, 0.86) between γ and σσ for food dispersions with undisturbed structure (UDS) and with broken down structure (BDS). Data obtained under Cσ were also used to calculate shear moduli of foods.