摘要:

ABSTRACTMorphological and chemical aspects of fish muscle texture are reviewed and differences from red meat are pointed out. A unique feature of fish muscle is its low connective tissue content which accounts for easy disintegration of fish flesh on heating. Thus, the muscle fibers are the main textural elements in cooked fish meat. Because of this, most of the popular texture testing instruments are not applicable to fish. Best results are obtained with the thin blade shear/compression cell.Texture of fish muscle is affected by the species, age and size of the fish within the species, and nutritional state. Postmortem factors influencing texture include glycolysis, rigor mortis and the accompanying contraction of the muscle often leading to the separation of muscle segments (gaping), temperature profile during storage, temperature of cooking, pH and presence of NaCl.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTSounds emitted by eighteen foods were positioned in one‐ and two‐dimensional spaces by the nonmetric multidimensional scaling (MDS) algorithm MINISSA. Each of the eighteen food sounds was also scored on15sensory acoustical quality attributes. These sensory quality data were then used to study and interpret the MDS graphical representation. The results suggest two basic sensory criteria for distinguishing food sounds. One of these criteria, loudness, influences the intensity of many of the other acoustical qualities. The second criterion is unevenness or discontinuity. The continuous‐discontinuous quality of a sound provides a good description of the axes for both the one‐dimensional and the two‐dimensional MDS

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00863.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTStructural factors responsible for textural properties of heat‐induced soy protein gels were investigated using microscopic and mechanical testing techniques. The gels were prepared by heating20%soy protein pastes for30min at temperatures ranging from25to130°C. Gel hardness increased linearly with the heating temperature up to80°C, and decreased when the gels were heated at over90°C, especially over120°C. The equilibrium modulus estimated by tensile stress relaxation experiments was of the order of104‐ 105dyne/cm2, suggesting the presence of crosslinks, and there was a good correlation between the equilibrium modulus and the hardness of the gels. Solubility in phosphate buffer containing2‐mercaptoethanol and/or urea suggested that the gel network was formed through crosslinking of the disulfide‐, hydrogen‐ and hydrophobic‐bonding types, and that the textural properties were governed by the degree of the network formation controlled by the heating temperature. SEM images of the80°C‐induced hard gels revealed a porous structure having membranous walls of thin compact film. With the40°C‐induced soft gels, the formation of the porous structure was not yet adequate, while a partial collapse of this structure was observed in the120°

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00864.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTWhen starch powders are mixed with water and heated at or above the gelatinisation temperature, the granules absorb large quantities of water and form a viscous paste. The gelatinised pastes are shear‐thinning fluids, whose flow curves fit the expressionn̈=kγmover a wide range of shear rates. Behaviour at very low shear rates indicates the existence of a yield stress. Under oscillatory shear the elastic moduli of the pastes considerably exceed the loss moduli, and both show only weak dependence on frequency over the range 0.002‐2.5 Hz.The apparent viscosities, pseudoplasticity constants, yield stresses and elastic moduli of the pastes are all concentration dependent, assuming significant values only when the starch level exceeds a minimum concentration. In many cases this threshold concentration corresponds closely to the point at which the volume of flocculated swollen starch granules just fills the total volume of the s

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00865.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTA torsion test was developed for studying the structural failure of selected raw fruits and vegetables. Apple, melon and raw potato flesh were tested at a shear strain rate of approximately 0.26s‐1in torsion and uniaxial compression. Low strain modulus values were determined in addition to shear stresses and normal strains at failure.Results corroborated the maximum normal strain failure criterion proposed by Segerlind and Dal Fabbro (1978) for apples and suggested its application to potatoes and melons if true strains are used rather than engineering strains. The maximum shear stress theory also seemed to be a possible failure criterion for potatoes. Results comparing compressible and incompressible materials suggest that bulk strain affects the shear stress at failure. The observed failure planes supported the quantitative results for stresses at failure. Scanning electron micrographs indicated that the cellular failure occurred in the cell wall, regardless of whether it was due to tension,Varying specimen lengths or diameters had negligible effects on the uniaxial compression modulus but did affect the shear stress at failure in a manner yet to be satisfactorily explaine

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00866.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTRatings by a trained texture profile panel were compared with the mechanical properties (shear stress at structural failure, normal strain to failure and apparent elastic modulus) determined in torsion and uniaxial compression for apple, melon and Irish potato flesh.Results indicated that, for melon and potato flesh, the structural failure stress levels were more frequent and significant indicators of sensory note magnitudes than the modulus values. The reverse was true for apple flesh. Of the sensory notes, moisture release correlated most consistently with the mechanical properties.Melon flesh failed in uniaxial compression by widespread crushing rather than along a failure plane. Correlation of the mechanical failure stress with the first bite sensory notes dominated in this case. The structural failure of potato flesh in uniaxial compression generally occurred along a single plane of maximum shear stress which left two essentially intact pieces of specimen. First bite and mastication sensory notes for potato flesh correlated with shear stress at failure about equally well. The structural failure of apple tissue in uniaxial compression was caused by general compression failure with many fragmented pieces of tissue remaining. Apple flesh produced the most frequent correlations of both first bite and mastication texture notes with the instrumental modulus and failure values.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00867.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTAnalysis was made of cone penetration test parameters for butters of a wide range of firmness. The relationship:accounted for 96.9% of the variation in the observations. This relationship, which has the dimensions of stress, differs from the previously proposed rheological models. An index, based on this relationship, was found to account for approximately 91% of the variation in the sensorially perceived spreadability of the butters.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00868.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTAn instrumental method for evaluating the ease of extrusion of a decorative cake icing marketed in plastic tubes is demonstrated. The force is measured to pull the tube between two rollers to extrude the contents through the tube nozzle or, by increasing the gap between the rollers, to back extrude the contents within the tube. The maximum force, used as a textural indexy correlated with sensory assessments. The instrumental readings were affected by sample temperature, deformation rate and nozzle size and shape so that these conditions must be standardized. The method has potential use in testing a variety of products marketed in tubes.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00869.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Book reviews in this article:Polysaccharides in Foods.J. M. Blanshard and J. R. Mitchell eds.Fundamentals of Food Engineering.Third Edition. S. E. Charm.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00870.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

GENERAL PRINCIPLES: Structure Collapse During Lyophilisation. D. Simatos.GENERAL PRINCIPLES: Viscosity of an Intermediate Moisture Dough. N. W. Cervone and J. M. HarperGENERAL PRINCIPLES: A Viscosity Model for a Cooking Dough. C. H. Remsen and J. P. ClarkINSTRUMENTATION AND METHODOLOGY: A Brief Note on Two Simple Systems for Evaluating Characteristics Related to Yoghourt Texture. F. Sauvageot.INSTRUMENTATION AND METHODOLOGY: Some Measuring Installatione in Food Rheology. J. L. Ilari.OBJECTIVE MEASUREMENTS: Utilization of Peanut Rotein and Oil in Cheese Analogs. S. L. Chen, P. J. Wan, E. W. Lusas and K. C. Rhee.FACTORS AFFECTING TEXTURE: Effect of Degree and Pressure of Milling on the Stickiness of Milled Parboiled Rice. A. Halim and K. R. Bhattacharya.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00871.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY