摘要:

AbstractTechniques used to measure the eggshell strength and associated parameters are reviewed. Much of the early research was based on crude instruments that did not adequately control test conditions, particularly the rate of applying force to the shell. Better instruments have been used recently to obtain precise readings. A significant advance has been the development of techniques to describe the physical properties of the shell material. This is potentially more meaningful than the empirical comparisons of egg behaviour, and is leading to a better understanding of the shell fracture mechanism.Two practical tests are currently available to the biologist for non‐destructive measurements: specific gravity of the egg and shell deformation under a non‐destructive force. Both predict ‐ with acceptable precision ‐ the shell fracture force.Eggshell strength has been investigated for over 70 years, but an ideal test method has yet to be found, and research is still r

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01099.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe need to select relevant sensory and instrumental variables is discussed and illustrated by an example concerned with the textural characteristics of a gel system. Discriminant analysis is used to identify the important sensory and instrumental variables and multiple regression to verify that the instrumental variables contain the required information. The limitations of this approach and possible modifications to deal with particular problems are also discussed. The approach described has proved successful in a number of applications

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01100.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractData on moisture, protein content and pH (after 24 h in ice post mortem) of the flesh of cod of different sizes, captured during several fishing expeditions from Aberdeen to northern fishing grounds in spring and autumn, have been examined in relation to the texture of the cooked material. It is concluded that large fish are slightly tougher than small fish, even when the pH is the same. In addition, the pH of large fish is often lower than that of small fish, so the relative toughness of large fish is enhanced. However, the size‐pH relationship is clearly defined only in well‐fed fish at certain times of the year. At other times, when food is scarce, the post‐mortem pH of the muscle of all sizes of cod varies within wide limits, so that size no longer appears to influence the texture.Of the parameters studied, the post‐mortem pH correlated best with the texture after cooking. Since fish with a high pH usually have a high water content, there was also a correlation between texture and moisture. However, the protein content seemed to exercise a negligible influence on texture, an unexpected finding considering that protein accounts for nearly all the ‘substance’ of white fish flesh after the water has b

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01101.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe Magness‐Taylor pressure tester is used extensively as a firmness measuring device for convex‐shaped fruits. Researchers have been interested to learn what is really being measured by this device when its probe is pressed against the fruit to the point of flesh rupture. This investigation analyzes the mechanics of deformation of Rome Beauty apples, with the skin sliced off, in two deformation stages namely prior to and after puncturing of the flesh. Theories of inelasticity and piercing problem are adopted in analyzing the theoretical stress distribution. With the stress distribution, the theoretical force‐deformation relations were found which show the effect of probe size, shape, radius of curvature, and the mechanical properties of the fruit. Experimental tests included simple compression of cylindrical specimens of the flesh, punch shear tests of slices of the flesh, and pressure tests of whole pared fruits. With the 5/16‐in. probe, agreement between experimental and theoretical results was within 1.5 % and 2.2 % for the first and the second deformation stage, respectively.Results showed that; (1) the Magness‐Taylor pressure test involves a combination of shear and compression stresses; (2) an average conversion factor of 1.85 can be used to convert readings by a 5/16‐in. rigid die to those by a 7/16‐in. die; and (3) shearing strength of the flesh is the only mechanical property needed to predict the maximum force reading after puncturing

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01102.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe relationship was measured between the normal contact force and the force required to overcome friction between food samples and a surface simulating a typical texture test cell. Peas produced frictional behavior that combined the characteristics of dry friction and fluid flow. Friction coefficients for selected foods ranged from 0.04 to 0.52. Friction force was linearly related to the normal contact force and non‐linearly to the area of contact between the sample and the surface, and the speed of the sample relative to the surface. This verifies the fact that, with empirical texture test devices, these test variables must be held constant.The estimated friction forces represented a significant amount of the total force required to operate a wire extrusion cell and a back extrusion cell. It was concluded that standardization of the test cell would be easier to achieve if the contact area between the sample and the cell surfaces was minimized and if low friction materials were used to construct the cell

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01103.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

Book reviews in this article:M. J. Sparnaay,The Electrical Double Layer,R. H. Ottewill, J. Lyklema, and R. Parsons (eds.),

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01104.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

General Principles: ‘Wheat and Flour Proteins, Recent Research’, by D. K. Mecham.General Principles: ‘Hydrated Protein Fibrils from Wheat Endosperm’, by J. E. Bernardin and D. D. Kasarda.General Principles: ‘Rheological Properties and Structure of Kamaboko XII. Dependence of the Stress Relaxation Moduli on Myofibrillar Protein Concentration in Kamaboko’, by I. Takagi.General Principles: ‘Texture of Bread and Baked Goods’, by L. Wasserman.General Principles: ‘Age Related Properties of Collagen Solutions. A Viscometric Treatment’, by L. C. Cerny, D. M. Stasiw, and W. C. Tinelli.General Principles: ‘The Texture of Cooked Potatoes. A Review’, by D. S. Warren and J. S. Woodman.General Principles: ‘The Estimation of Rheologically Important Thiol and Disulphide Groups in Dough’, by Ian J. Jones, J. W. Phillips, and F. J. Hird.General Principles: ‘Stress Relaxation in Wheat Flour Doughs Following a Finite Period of Shearing. I. Qualitative Study’, by B. Launay and J. Buré.General Principles: ‘Submicroscopic Structure of Wheat Flour and Gluten Lipoprotein Components’, by N. Crozet, B. Godon, L. Petit, and A. Guilbot.General Principles: ‘ModifiedOpaque‐2Corn Endosperms. II. Structure Viewed with a Scanning Electron Microscope’1by J. L. Robutti2, R. C. Hoseney3, and C. E. Wassom3.General Principles: ‘Studies of Glutenin. VII. Inheritance of Its Physicochemical Factors in Triticale’ by R. A. Orth, B. L. Dronzek, and W. Bushuk.General Principles: ‘A Gel Consistency Test for Eating Quality of Rice’, by G. B. Cagampang, C. M. Perez, and B. O. Juliano.Instrumentation and Methodology: ‘Instrumental Evaluation of the Effects of Cosmetic Products on Skin Surfaces with Particular Reference to Smoothness’ by J. K. Prall.Instrumentation and Methodology: ‘Correlation Between the Specific Work of Deformation and Penetrometer Values for Consistency Measurement’, by G. Blüher, H. Herrmann, J. Worf, and H. J. Raeuber.Instrumentation and Methodology: ‘An Accessory to the Weissenberg Rheogoniometer for the Measurement of Viscoelasticity of Surface Layers of Protein Solutions’, by R. G. King and A. L. Copley.Objective Measurements: ‘A Note on the Effect of Varying Atmospheric Pressure on the Amylograph Viscosity of Flours’ by K. Lorenz.Objective Measurements: ‘Resistography. A Dynamic Quick Method to Classify Wheat and Flour Quality’, by M. Brabender.Objective Measurements: ‘Eine dynamische Schnellanalyse an Teigen für die Weizen‐ und Mehlqualitätsbeurteilung mit dem Resistographen’, by M. Brabender.Objective Measurements: ‘Vergleichende Beurteilung physikalischer Verfahren zum Messen der Krumenkonsistenz, by B. Thomas and A. Juretko (Berlin).Objective Measurements: ‘Measurement of Spaghetti Texture by Texturometer and Texture Evaluation of Packaged Spaghetti’, (in Japanese), by Y. Yamano, T. Yamashita, and F. Y. Fukiu.Objective Measurements: ‘Texture Measurements of Kamaboko by Texturometer and Universal Testing Machine’ (in Japanese), by Y. Yamano, M. Emoto, and Y. Fukui.Objective Measurements: ‘Eating Qualities of Cooked Rice Stored in an Electric Jar’, (in Japanese), by Y. Yamano, M. Takagawa, and Y. Fukui.Factors Affecting Texture: ‘A Review of Bread Staling’ by H. F. Zobel.Factors Affecting Texture: ‘Influence of Alum on the Firmness of Fresh‐Pack Dill Pickles’, by J. L. Etchells and T. A. Bell.Factors Affecting Texture: ‘Influence of Different Organic Acids on the Firmness of Fresh‐Pack Pickles’, by T. A. Bell and J. L. Etchells.Factors Affecting Texture: ‘Effect of Pre‐Slaughter Injections of Papain on Toughness in Lamb Muscles Induced by Rapid Chilling’, by D. N. Rhodes and E. Dransfleld.Factors Affecting Texture: ‘The Effect of Manufacturing Conditions on the Setting Rate of Butter’, by M. W. Taylor, R. M. Dolby, and R. W. Russell.Factors Affecting Texture: ‘Assessment of Field Performance and Fruit Quality of the Range of Strawberry Clones’, by J. MacLachlan and R. Gormley.Sensory Evaluation: ‘Complex Sensory Assessment’, by J. M. Harries.Sensory Evalu

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1974.tb01105.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY