摘要:

ABSTRACTSLow steady shear deformation and small amplitude oscillation measurements have been used to characterize the onset of gelation in high‐methoxyl pectin gels. A simplified technique with a shear modulus threshold criterion is proposed for routine evaluation of the gelpoint with a normalized parameter. Limiting conditions of the three methods are discusse

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00507.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTCylindrical specimens of bread crumbs were subjected to a compression‐decompression cycle using a computer interfaced Universal Testing Machine during 11 days of storage at ambient temperature. The strain (% deformation) was set at various levels in the range of 20–80%. The overall work per unit volume, calculated from the area under the stress‐strain curve, increased exponentially with the imposed strain while the percent recoverable work, calculated from the area under the decompression curve, decreased exponentially with the strain. The loss of elasticity that accompanies bread aging was clearly manifested in the percent recoverable work, irrespective of the imposed strain. It declined in a manner that could be described by a power law or an exponential decay model at the same degree of fit as judged by statistical cri

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00508.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTThe rheological properties and water uptake in the white muscle m.cutaneus trunciand the red muscle m.masseterof Norwegian red cattle were compared. The two muscle systems were examined intact, ground and chopped, at two different salt levels, and unheated as well as heated to 70C. Three different rheological parameters were recorded: the complex modulus, the phase angle and a parameter measuring nonlinear viscoelastic properties (called deformation index). The white muscle had, in general, the highest complex modulus, the highest phase angle and the lowest deformation index. The variation imposed on the data by the pH variation accompanying different fibre types, made direct comparisons between the two muscles difficult. It is suggested that the complex modulus for unheated systems was most sensitive to fibre type differences. The different rheological parameters recorded revealed different sensitivity to the variables investigated. The complex modulus, measured on unheated systems, were insensitive to the degree of comminution while both the phase angle and the deformation index were sensitive to this mechanical treatment. To record different rheological parameters might therefore be useful when establishing nondestructive viscoelastic measurements for on‐line quality control in factories. However, it is felt that such measurements must be supported by other rapid measurements to fully utilize their potentia

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00509.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTMarshmallows of a national and supermarket brand were subjected to four successive compression‐decompression cycles using a computer interfaced Universal testing machine and the total and recoverable work in each cycle determined. The two brands were significantly different. Differences were maintained irrespective of the deformation rate (10 and 20 mm.min–1), the magnitude of imposed strain in the range of 15–40% and the time between the cycles (0, 30 and 60 s). It appears that the discriminatory power of the test decreases as the magnitude of the imposed strain incr

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00510.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTTorsional 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.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00511.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ABSTRACTData are presented for the elastic moduli of gelatinised dispersions of a range of starch types, including native and chemically modified starches, over a much wider concentration range than examined heretofore. As found previously, there is a threshold concentration for measurable elasticity, near the close‐packing point, and a concentration region above this over which elasticity increases roughly linearly with concentration. A second, higher, “threshold” concentration at which a fairly sharp slope change occurred was also found. Three types of behaviour were found, apparently corresponding to the distinction between chemically modified starches, root and tuber starches, and cereal starches. At the second threshold concentration these, respectively, showed a significant fall in slope, little or no slope change and a marked slope increase. A recent study (Evans and Lips 1990) has provided a useful description of the elastic properties of concentrated dispersions of model deformable particles. Comparison between the behaviour of the “baseline” model dispersions with that of the starch dispersions examined here reveals significant similarities, especially when considering the behaviour of the chemically modified starches. There are some noteworthy differences which raise important questions about the structural origins of the rheological properties of starches and we briefly speculate ab

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00512.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

ADVANCES IN CEREAL SCIENCE AND TECHNOLOGY, Vol. 10. Y. Pomeranz, ed.PROCEEDINGS OF THE THIRD CONGRESS ON FOOD RHEOLOGY, Held in Detmold, September 11–13, 1990. W. Seibel, e

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00513.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

GENERAL PRINCIPLES: Distinguishing Among Bruises in Peaches Caused by Impact, Vibration and Compression. P.J. Vergano, R.F. Testin, and W.C. Newall, Jr.GENERAL PRINCIPLES: Prediction of Physical Dough Properties from Glutenin Subunit Composition in Bread Wheats: Correlation Studies. R.B. Gupta, F. Bekes, and C.W. WrigleyGENERAL PRINCIPLES: A Mechanism of Bread Firming. I. Role of Starch Swelling. M.L. Martin, K.J. Zeleznak, and R.C. HoseneyGENERAL PRINCIPLES: A Mechanism of Bread Firming. II. Role of Starch Hydrolyzing Enzymes. M.L. Martin and R.C. HoseneyGENERAL PRINCIPLES: Prediction of the Non‐Linear Viscoelastic Properties of a Hard Wheat Flour Dough Using the Bird‐Carreau Constitutive Model. S.J. Dus and J.L. KokiniGENERAL PRINCIPLES: The Study of the Glass Transition of Glutenin Using Small Amplitude Oscillatory Rheological Measurements and Differential Scanning Calorimetry. A.M. Cocero and J.L. KokiniGENERAL PRINCIPLES: The Cox‐Merz Rule Extended: A Rheological Model for Concentrated Suspensions and Other Materials with a Yield Stress. D. Doraiswamy, A.N. Mujumdar, I. Tsao, A.N. Beris, S.C. Danforth and A.B. MetznerGENERAL PRINCIPLES: Characterization of Nonlinear Creep Behavior of Two Food Products. R. Lu and V.M. PuriGENERAL PRINCIPLES: The Nonlinear Elastic Behavior of Polydisperse Hexagonal Foams and Concentrated Emulsions. A.M. Kraynik, D.A. Reinelt and H.M. PrincenGENERAL PRINCIPLES: A Test Cell for Meat Cohesiveness Using the Instron Universal Testing Machine. H.W. Ockerman, D.M. Greene and R.R. HodgesGENERAL PRINCIPLES: Results of Testing Sensory Evaluation Methods. P. Molnar, V. Nágel and L. KatonaGENERAL PRINCIPLES: Universal Laboratory Texturometer. Á. ÁlmosGENERAL PRINCIPLES: Textural Determination of “Montomorency” Cherries Using Shear/Compression and Stone Removal. C.R. Santerre, J.N. Cash and A.F. IezzoniGENERAL PRINCIPLES: A Device to Measure the Dynamic Shear Properties of Small Samples. M.E. Mackay and C.A. CatheyGENERAL PRINCIPLES: A Probe Impact Sensor for Fruit Firmness Measurement. M. Delwiche and Y. SarigGENERAL PRINCIPLES: Prediction of Apple Bruising Due to Impact on Different Surfaces. P. Chen and R. YazdanuGENERAL PRINCIPLES: Impact Bruise Resistance of Peaches. G.H. Brusewitz, T.G. McCollum and X. ZhangGENERAL PRINCIPLES: Triaxial Test Sample Size Effect on Stress Relaxation of Wheat En Masse. R.G. Bock, V.M. Puri and H.B. ManbeckGENERAL PRINCIPLES: Electromyographic Measurement of Textural Changes of Foodstuffs During Chewing. H. Sakamoto, T. Harada, T. Matsukubo, Y. Takaesu and M. TazakiGENERAL PRINCIPLES: Evaluation of Food Texture by the Masticatory Pattern. I. Analysis of Chewing Force Pattern in the Mouth. J. Takahashi and F. NakazawaGENERAL PRINCIPLES: The Measurement of Mechanical Properties of Cheese. J.H. Dobrzycki and N. Baryko‐PikielnaGENERAL PRINCIPLES: A Simple Antibody‐Based Test for Dough Strength. I. Development of Method and Choice of Antibodies. J.H. SkerrittGENERAL PRINCIPLES: II. Genotype and Environmental Effects.INSTRUMENTAL MEASUREMENTS: Oscillatory Rheometry of Starch‐Water Systems: Effect of Starch Concentration and Temperature. L.M. Hansen, R.C. Hoseney and J.M. FaubionINSTRUMENTAL MEASUREMENTS: Characterization of the Maturation Process by Changes in Pineapple Fruit Texture. H. Vega‐Mercado and I. Beauchamp de CaloniINSTRUMENTAL MEASUREMENTS: Relationship of Properties of Rice to Texture of Japonica and Japonical/Indica cooked rice. Y.H. Hong, H.S. Ahn, S.K. Lee and S.K. JunINSTRUMENTAL MEASUREMENTS: Investigations on the Physical Properties of Whipped Egg White Foam by the Multi‐Biting Test. S. TsujiCORRELATING SENSORY WITH INSTRUMENTAL MEASUREMENTS: Prediction of Sensory Evaluation of Gel Texture by Instrumental Measurement. Y. Watanabe, K. Amaike, T. Tomita and H. AokiCORRELATING SENSORY WITH INSTRUMENTAL MEASUREMENTS: Textural Classification of Foods Based on Warner‐Bratzler Shear. N. ChandCORRELATING SENSORY WITH INSTRUMENTAL MEASUREMENTS: The Relation Between Instrumental Firmness Measurements and Sensory Chewing Texture of Briihwurst Sausages. P.G. KlettnerSENSURY ASSESSMENT: Sensory Analysis of Fiber Formulated Ground Pork Patties. S1. Todd, F.E. Cunningham, J.R. Schwenke and S.J. Goetsch.SENSURY ASSESSMENT: Sensory and Instrumental Evaluation of the Mouthfeel of Beer. S.A. Langstaff, J.‐X. Guinard and M.J. LewisSENSURY ASSESSMENT: The Effect of Temperature on Carbonation Perception. N.J. Newton Yau and M.R. McDanielSENSURY ASSESSMENT: Evaluation of Cooking Quality of Potatoes Using Sensory and Instrumental Methods. I. Sensory Evaluation. G. Böehler, F. Escher and J. SolmsFACTORS AFFECTING TEXTURE: Breakage Susceptibility of Shelled Corn Due to Rehydration and Redrying. L.G. Tabil, A. Noomhorm and L.R. VermaFACTORS AFFECTING TEXTURE: Dry Bean (Phaseofus vulgaris) Hardening and the Consequences of Pectin Methylesterase Activity in Storage. M.M. Mafuleka, D.B. Ott, G.L. Hosfield and M.A. UebersaxFACTORS AFFECTING TEXTURE: Shelf‐Life Extension of Michigan Apples Using Sucrose Polyester. Y.‐L. Chai, D.B. Ott and J.N. CashFACTORS AFFECTING TEXTURE: Precooling and Modified Atmosphere Storage of Green Asparagas. Y. Gari Cpy, G.S.V. Raghaven, F. Castaigne, J. Arul and C. WillemotFACTORS AFFECTING TEXTURE: Texture Analysis of Cheddar Cheese Made From Ultrafiltered Milk. S. Lakhani, E.A. Gullett, L.K. Ferrier and A.R. HillFACTORS AFFECTING TEXTURE: Ultrastructural and Textural Changes in Processed Carrot Tissue. E.M. Ahmed, S. Mirza and A.G. ArreolaFACTORS AFFECTING TEXTURE: The Effect of Marination and Cooking on the Mechanical Properties of Intramuscular Connective Tissue. G.J. Lewis and P.P. PurslowFACTORS AFFECTING TEXTURE: Effect of Vacuum Packaging on Changes Associated with Frozen Cod Fillets. M.E. Sirois, B.M. Slaby, R.H. True and R.E. MartinFACTORS AFFECTING TEXTURE: Rheological and Structural Properties of Wiener‐Type Products Substituted with Vital Wheat Gluten. C.‐Y. Ma, S.H. Yiu and G. KhanzadaFACTORS AFFECTING TEXTURE: Effect of Washing on the Texture and Microstructure of Frozen Fish Mince. K.S. Yoon, C.M. Lee and L.A. HufnagelFACTORS AFFECTING TEXTURE: Influence of Cultivar, Fruit Maturity and Fruit Anatomy on Apple Sauce Particle Size and Texture. W.P. MohrFACTORS AFFECTING TEXTURE: Mechanical Properties of Composite Fruit Products Based on Hydrocolloid Gel, Fruit Pulp and Sugar. A. Nussinovitch, I.J. Kopelman and S. MizrahuFACTORS AFFECTING TEXTURE: Effects of Freezing Rate and Storage Time on the Structural Properties of Minced Meat. G.S. Mittal and S. BarbutRELATIONSHIP TO STRUCTURE: Mechanics of Parenchyma Tissue Based on Cell Orientation and

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1992.tb00514.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY