摘要:

ABSTRACTA general classification scheme is proposed which recognizes organizational, architectural and relative meanings of food structure and how these relate to textural properties. Within the architectural (or constructive) meaning, one can recognize certain elementary structures which give rise to homogeneous or heterogeneous compounded structures, and permeated or embedded types. Depending on the level of magnification needed, one can also speak of macro‐, micro‐, and ultrastructures. Specific examples are given and the relatonship between structure and processing is pointed

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00320.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTConditions for the formation of liquid two‐phase water—protein—polysaccharide systems containing the main classes of proteins, as defined by Osborne, and various acid and neutral polysaccharides have been determined. Phase diagrams of some of these systems have been obtained. It is shown that, proceeding from liquid two‐phase water—protein—polysaccharide systems, one can obtain different protein products without using

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00321.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTBacon lean was examined for its textural and structural characteristics and the influence upon them of cooking. Examination by light, scanning and transmission electron microscopy of cooked bacon lean led to the conclusion that the major effects of heating relative to texture include a decrease in interfiber spacing and fracturing. Cooking removed over 95% of the moisture and 75% of the lipids. Sensory analysis of bacon lean was accomplished by the use of a four‐stage evaluation form requiring tactile, audio and oral judgements. Of the eight instrumental methods evaluated for their ability to measure changes in bacon lean as a function of cooking, the blunt biting cell, 2 mm penetration and the Warner‐Bratzler Shear were judged the most useful. Both the sensory and instrumental measurements suggested that cooking produces a nonlinear progression in bacon lean from noncrisp to crisp to brittle. These changes are a consequence of structural alterations resulting from compositional changes. Several of the instrumental tests correlated well with sensory data. Regression analysis indicated that between 80 and 90% of the total variation in sensory data (with the exception of overall acceptability) could be explained by the initial slope of the force deformation curve in the Warner‐Bratzler

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00322.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTParboiling seemed to produce significant changes in the pasting behaviour of rice. But comparison of Brabender viscograms obtained at a fixed slurry concentration did not provide a clear understanding of the changes. Study of viscograms of a number of differently parboiled samples determined at several slurry concentrations each indicated that the viscogram patterns were essentially similar in all respects except one: The lowest peak viscosity at which a measurable breakdown first appeared was pushed towards higher viscosity values and higher concentrations in parboiled rice, proportional to its severity, as compared to raw rice. This suggested a decreased swelling ability of the granules in parboiled rice as compared to raw rice.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00323.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTThe viscosity of 1% sodium alginate and 1% sodium pectate solutions containing low levels of calcium chloride were investigated using cone and plate viscometers. The level of calcium required to initiate partial gelation was significantly lower for pectate compared with alginate. With increasing calcium chloride concentration the solutions became more pseudoplastic and eventually showed thixotropy.One percent bovine serum albumin or 1% myoglobin was incorporated into the polysaccharide solutions together with sufficient calcium to cause incipient gelation in the absence of the protein. Myoglobin inhibited the formation of an alginate gel, the effect being greatest at a pH of about 6.3. Bovine serum albumin also inhibited alginate formation, the effect increasing with increasing pH. In contrast the addition of both myoglobin and bovine serum albumin caused gel formation in the presence of pectate below pH 6.0.The results are discussed in terms of the protein/polysaccharide interactions and the polymer/ion interactions that can take place in these systems. The relevance of this work to the use of these polysaccharides as thickeners and gelling agents in canned meat products is considered.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00324.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTMelting temperatures were determined for 1‐5% agarose gels, 7.5‐40% gelatin gels and mixed gels of different concentrations of the two hydro‐colloids. The dynamic viscoclastic constants were also quantified at 0.05 HZ for mixed gels containing 0.5% agarose and 2.5–20% gelatin.In single component gels, the melting temperature increased with hydrocolloid concentration. The melting temperature of gelatin gels was lower than that of agarose gels (22–31°C vs 69–80°C) and less concentration dependent. The melting temperature of mixed gels was more similar to that of agarose gels at low (2.5–6.25%) gelatin concentrations and more similar to that of gelatin gels at high (7.5–20%) gelatin concentrations. The storage modulus decreased with increasing temperature indicating that the thermal rupturing of the noncovalent crosslinks in the gels was stronger than the entropic behavior of the network. The temperature dependence of the storage modulus and of the dynamic viscosity increased with gelatin concentration. Based on these results and on the determination of the activation energy it is concluded that, in mixed agarose/gelatin gels, the two species form individual networks which interfere with one another at hi

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00325.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTFourteen low‐methoxyl pectins were used to prepare a 30% sucrose gel with a final pectin concentration of 0.8% and an added calcium content of 25 mg Ca++/g pectin. The texture of each gel was evaluated using three descriptors: firmness, coarseness, and graininess. The relaxation behavior of the 14 gels, under a constant strain, was monitored using an Instron universal testing machine. The data were best defined by an equation that is represented by two Maxwell bodies in parallel. The elastic moduli and relaxation times of this model ranged, between gels, from 2881 Pa to 5487 Pa and from 4.1 s to 908 s, respectively. An apparatus constructed in this laboratory was used to measure the creep behavior of the gels under constant stress. The normal creep behavior of the 14 gels was best defined by the Burger's Model. The elastic moduli and viscous constants of this model ranged, between gels, from 3937 Pa to 15,342 Pa and from 20,300 Pl to 40,100 Pl, respectively. The relaxation modulus, E1, was the most sensitive for distinguishing significant differences between the gels. Several significant correlations were found between rheological, chemical and textural parameter

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00326.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

ABSTRACTTwenty subjects judged the crispness, loudness, and firmness of sixteen food samples by both biting and chewing and by only biting the foods. These subjects also scored the foods for thirteen textural qualities. Instrumental measures of slope, peak force, and deformation to fracture were obtained for the sixteen foods from a snap test at four deformation rates. Whether a subject judged an attribute by the bite or the bite and chew technique made little or no difference in the sensory judgments. Crispness appeared to be very closely related to loudness and less closely related to firmness. Loudness of the chewing sounds was more closely related to crispness than to firmness. Of the sensory qualities studied, loud, snap, and crackly were the three most closely related to crispness. Of the instrumental parameters Young's Modulus generally had the highest correlation with the crispness of all foods and peak force generally had the highest correlation with firmness. Deformation rate had minimal effects on measures of flexure or peak force, but its effects on Young's Modulus were frequently large and irregular. A vibrotactile‐acoustical hypothesis for crispness is propose

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00327.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

GENERAL PRINCIPLES: Effects of Disulfide Bond on the Gel Formation of Myosin B and/or Soy Protein. CIF. Seiichi Haga and Iomio Ohashi.GENERAL PRINCIPLES: Effects of Ca2+and Mg2+on Gel Formation of a Mixture of Myosin B with Soy Protein CIF. Seiichi Haga and Tomio Ohashi.GENERAL PRINCIPLES: The Effect of Heat Processing on the Structure and Rheological Properties of Carrageenan Gels. P. A. Ainsworth and J. M. V. Blanshard.GENERAL PRINCIPLES: Observation of Internal Structure of Casein Submicelles by Means of Ion BeamINSTRUMENTATION AND METHODOLOGY: A Sca!?Ziilg Electron Microscopy Stady of Japanese Noodles. J. E. Dexter and B. L. Dronzer.INSTRUMENTATION AND METHODOLOGY: Apparatus for Monitoring Cake Structure Development During Baking. P. W. Voisey.INSTRUMENTATION AND METHODOLOGY: An Evaluation of the Rapid Amylograph Method. B. A. Marchylo and F. G. Kosmdak,INSTRUMENTATION AND METHODOLOGY: Silver Proteinate Staining of Neutral Polysaccharides in Apple Cell Walls: Implications Relative to Fruit Firmness. W. P. Mohr.INSTRUMENTATION AND METHODOLOGY: Texture Studies on Edible Protein Fibres Produced By A Wet Spinning Technique. I. Fibres Produced From Casein and Carrageenan. G. Downey* and K. J. Burgess**.INSTRUMENTATION AND METHODOLOGY: Texture Studies on Edible Protein Fibres Produced by a Wet Spinning Technique. 11. Fibres Produced From Casein and Alginate. G. Downey* and K. J. Burgess**.INSTRUMENTATION AND METHODOLOGY: Mechanism of Gel Formation By Low Methoxyl Pectins. R. A. Padival, S. Ranganna and S. P. Manjrekar.INSTRUMENTATION AND METHODOLOGY: A Comparison of the Texture of Expanded Milk Protein Extenders and TVP. J. J. Tuohy, K. J. Burgess and L. Lambert.INSTRUMENTATION AND METHODOLOGY: The Use, o f hlutton Tallow Fat in Fish Sausages. H. Turgut, D. Pearson and J. Rwnnan.INSTRUMENTATION AND METHODOLOGY: Assessment of Polysaccharides as Ice Cream Stabilisers. John I. L. Cottrell, G. Pass and G. 0. Phillips.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1980.tb00328.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY