摘要:

ABSTRACTWhole 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 bruisin

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTCompressive force‐deformation curves of solid foods with upward and downward concavities are described by a power law and two, two‐parameter mathematical models that can be transformed into linear equations by rearrangement. The fit of the latter to experimental data was comparable to or better than that of a two‐parameter power law model. These two models can simplify the procedure and shorten the time of data processing in certain applications of computer interfaced testing machines. Their main advantage over the power law model, however, is that they can facilitate the analysis of the compressive behavior of double‐layered arrays of objects in general and that of finger(s)‐food system in p

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00019.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTA 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 res

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00020.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTThe effect of polysorbate‐60 in improving the stability of model oil‐in‐water emulsions formulated with xanthan gum and propylene glycol alginate was studied at two levels of the surfactant; 0.15% and 0.30%. Creep measurements and steady shear measurements as well as surface tension and oil droplet size measurements were conducted to relate rheological and surface properties to improved stability. Higher polysorbate‐60 concentration resulted in lower surface tension values which shifted the oil droplet size distribution to a smaller size range; this distribution was a function of aging time at 0.15% weight concentration PS‐60. The decay in rheological parameters, particularly Newtonian viscosity, was slower at 0.30% surfactant conc

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00021.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTA simple and accurate procedure to determine the flow properties of powerlaw fluids using a paddle type mixer viscometer is described. The approach considers the mixer as analogous to a concentric cylinder system and incorporates the inclusion of end effects in modeling. The procedure significantly reduces data collection because calibration with standard fluids is not necessary to estimate average shear stress and shear rate values.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00022.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTThe 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 proc

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00023.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

ABSTRACTThe problem of hardness perception was examined by means of a psycho‐physical approach. The differential sensitivity was studied over a wide range of hardness (approximately 100 to 600 × 104Pa) with products displaying mainly elastic behavior.A series of five silicon elastomer samples were prepared, each series containing 6–8 samples of varying degrees of hardness. The rheological characteristics of these products were measured. Differential threshold and magnitude estimation tests were carried out by 10 subjects who were asked to make hardness comparisons by biting or squeezing the samples. There was no significant difference in sensitivity between molars and incisors as shown by the differential thresholds which varied between 4 and 11% depending on the hardness range. Pressing between the fingers gave less accurate performances than biting. The difference in sensitivity detected by the threshold measurements was not shown in the magnitude estimation t

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00024.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

Book reviews in this article:RHEOLOGY OF FOOD, PHARMACEUTICAL AND BIOLOGICAL MATERIALS WITH GENERAL RHEOLOGY.R. E. Carter, ed.MICROSTRUCTURAL PRINCIPLES OF FOOD PROCESSING AND ENGINEERING.J. M. Aguilera and D. W. Stanley, Elsevier Applied Science, 1990, 343 pp. $96.50.INTERACTIONS OF FOOD PROTEINS.N. Parris and R. Barford, eds. ACS Symposium Series 454, American Chemical Society, Washington, D.C., 1991, 294 pp. $59.95.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00025.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

GENERAL PRINCIPLES: Viscoelastic Behavior of f3‐Lactoglobulin Gel Structures.M. Stading and A.‐M. HermanssonGENERAL PRINCIPLES: Effect of Ammonium Salts on Rheological and Thermal Properties of Kappa‐Carrageenan Gels.M. WataseGENERAL PRINCIPLES: Dough Structure, Dough Rheology and Baking Quality.A. H. BloksmaGENERAL PRINCIPLES: Correlation of Protein Sulfhydryls with the Strength of Heat‐Formed Egg White Gels White Gels(Res. Note). B. A. MargoshesGENERAL PRINCIPLES: Effects of Temperature on Viscoelastic Properties and Activation Energies of Whey Protein Gels.K. KatsutaGENERAL PRINCIPLES: Rheological Characterization of Crosslinked Waxy Maize Starch Solutions Under Low Acid Aseptic Processing Conditions Using Tube Viscometry Techniques.R. V. DailGENERAL PRINCIPLES: Changing the Viseoelastie Properties of Cooked Rice Through Protein Disruption.B. R. Harnaker and V. K. GriffinINSTRUMENTAL MEASUREMENTS: Influence of Composition on the Resistance to Compression of Kappa Carrageenan‐Locust Bean Gum‐Guar Gum Mixed Gels: Relationship Between Instrumental and Sensorial Measurements.M. H. Damasio, S. M. Fiszman, E. Costell and L. DuranMETHODOLOGY AND INSTRUMENTATION: Impact Damage to Soybean Seed as Affected by Surface Hardness and Seed Orientation.M. D. Evans and R. G. HolmesMETHODOLOGY AND INSTRUMENTATION: Determining Viscosity of Fluid Foods by Continuous Lift(Res. Note). C. H. Runyon and K.L. McCarthyMETHODOLOGY AND INSTRUMENTATION: A Test for Evaluation of the Serum Separation Potential of Tomato Ketchup.N. G. Stoforos and D. S. ReidMETHODOLOGY AND INSTRUMENTATION: Use of a Kramer Shear Cell to Measure Cracker Dough Properties.D. W. Creighton and R. C. HoseneyMETHODOLOGY AND INSTRUMENTATION: Use of a Kramer Shear Cell to Measure Cracker Flour Quality.D. W. Creighton and R. C. HoseneyMETHODOLOGY AND INSTRUMENTATION: Physical and Structural Properties of Wheat Endosperm Associated with Grain Texture.G. M. Glenn and R. M. SaundersFACTORS AFFECTING TEXTURE: Instrumental and Sensory Evaluation of Textural Properties of Extrudates from Blends of High Starch/High Protein Fractions of Dry Beans.K. SkierkowskiFACTORS AFFECTING TEXTURE: Effects of Salts and pH on Heating‐Related Softening of Snap Beans.J. P. Van Buren, W. P. Kean, B. K. GavittFACTORS AFFECTING TEXTURE: Physical Properties as Indicators of Popping Characteristics of Microwave Popcorn.L. 0. Pordesimo, R. C. AnantheswaranFACTORS AFFECTING TEXTURE: Effect of Ingredients on Physical/Structural Properties of Extrudates.D. MooreFACTORS AFFECTING TEXTURE: Effect of Surimi Addition to Fresh Pasta on Ultra‐Structure and Cooked Firmness(Res. Note). S‐H. Kim, Y‐W. Huang and J. A. CarpenterbFACTORS AFFECTING TEXTURE: Effect of Manufacturing Conditions on Rheology of Banana Gelified Milk: Optimization of the Technology.A. Hamza‐ChaffaiFACTORS AFFECTING TEXTURE: Alginate Texturization of Highly Acid Fruit Pulps and Juices(Res. Note). G. Kaletunc, A. Nussinovitch and M. PelegFACTORS AFFECTING TEXTURE: Texture Characteristics of Reheated Bread. D. E. Rogers, L. C. Doescher and R. C. HoseneyFACTORS AFFECTING TEXTURE: Thermomechanical Analysis of Gluten‐Starch‐Water Mixtures. Influence of Testing Conditions and Composition.S. Cavella, L. Piazza and P. MasibFACTORS AFFECTING TEXTURE: Effect of the Attachment of Valine Residues on the Physicochemical and Functional Properties of Bovine Serum Albumin.Margaret C. Murphy and Nazlin K. HowellFACTORS AFFECTING TEXTURE: Flour Quality Tests for Selected Wheat Cultivars and Their Relationship to Arabic Bread Quality.Ken J.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00026.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1991.tb00027.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY