摘要:

AbstractThe linear viscoelastic properties of soy isolate doughs have been determined as a function of flour concentration and temperature using a Rheometrics Mechanical Spectrometer. The material of lowest concentration (15%) which is classified as a dispersion rather than a dough exhibited values of storage (G′) and loss moduli (G″) which increased with increasing temperature above 50°C. On the other hand, values of G′ and G″ for 20% and 25% doughs showed only a slight increase with increasing temperature. The shape of the G’ and G” versus frequency (ω) curves is suggestive of solid‐like behavior for the doughs. The shape of these curves does not change with temperature which indicates there is very little change in the ability of the protein molecules to undergo configurational rearrangements as the result of heating. The phenomenon of gelation does not arise in the doughs but only in the dispersion of lower concentration. The data indicate that the bonds between protein molecules are noncovalent in nature and that the process of cooking soy dough does not involve the formatio

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00532.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe texture of 10 milled rices cooked by a standardized method in excess water was measured in 11 laboratories using various instrument methods that had been developed specifically for national samples. The samples selected represented a wide range of rice textures. Instrument indexes for hardness and stickiness of cooked rice generally were more sensitive than the corresponding taste panel scores in discriminating among the 10 cooked rice samples. Instrument indexes for hardness correlated positively among each other as did those for stickiness. Most hardness indexes showed significant negative correlation with stickiness indexes. Most hardness indexes were positively correlated with amylose content whereas stickiness indexes were negatively correlated with amylose content. The continued use of amylose content as an index of eating quality in a rice breeding program is justified.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00533.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractTwo rheological properties of liquid foodstuffs often encountered in practice are the yield stress and the shear‐degradability (irreversible time‐dependence). Both these properties were determined for meat and yeast extracts using two rotational viscometers. The material constants were obtained and fitted with Bingham Plastic and Herschel‐Bulkley models for the meat extracts. The shear‐degradability exhibited by the yeast extract was quantified in terms of the energy required to destroy the material st

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00534.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe yield stresses of dispersions of guar gum (0.5–2.0% by weight) and gelatinized cornstarch (2.5–5.0% by weight) were measured using several different established experimental methods. The yield stresses in these polysaccharide dispersions result from intermolecular hydrogen bonding and molecular entanglements, thus the higher yield stress and hysteresis effect in guar gum dispersion was interpreted in terms of the greater hydrogen‐bonding density and molecular entanglements caused by the more extended chain conformation. The results confirm that there is no one absolute value for the yield stress of the hydrocolloid dispersions and that the viscoelastic characteristics of the test materials influence the shear rate and time dependence of yield stress. Therefore, experimental determination of yield stress must be made relevant to the practical applic

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00535.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractSoy bean lecithin was added to practical rations fed to 144 broiler chicks. The dark and white meats from frozen and non‐frozen carcasses were submitted to both mechanical (Warner Bratzler and Instron Universal Testing Machine) and sensory assessments of tenderness. A good correlation was observed between the two types of measurements. Regression equations indicated that higher lecithin contents in the rations decreased sensory toughness of the white meat. Freezing of the meats at – 40°C had little effect on tex

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00536.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractHeat induced changes in aged bovine m. longissimus dorsi (LD) and m. biceps femoris (BF) were studied by water bath cooking to 60, 70 or 80°C at slow (.12°C/min) and fast (.6°C/min) heating rates. Forcedeformation curves from the Warner‐Bratzler (WB) shear device were used to evaluate specific changes in the myofibrillar (WB M‐force) and connective tissue component (WB C‐force) of tenderness. Other measurements include WB peak force value, cooking loss, collagen solubility and sensory evaluations. Differences due to muscle type were significant in all parameters except collagen solubility. Both WB M‐ and WB C‐force were reduced by slow heating rate but for samples heated to 80°C, WB M‐force was affected only by heating rate below 60°C while WB C‐force was most influenced above 60°C. Effect of final temperature resulted in higher WB M‐force from 60°C to 70°C, whereas WB C‐force was most affected from 70°C to 80°C. On the contrary, WB peak force was less affected by final temperature. Due to concomitant and opposing changes in myofibrillar and connective tissue strength with increasing end point temperature, it is concluded that improvements in interpretations with regard to heat‐induced changes and response of heat treatment in various muscles may be increased by measurement of WB M‐force and WB C‐force fr

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00537.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00538.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

GENERAL PRINCIPLES: pH Dependence of the Rheological Properties of Hydrogels of Gelatin, Agarose and Konjak Mannan.M. WataseGENERAL PRINCIPLES: Compaction of Bulk Corn Kernel to Failure.P. B. McNulty and N. N. MohseninGENERAL PRINCIPLES: A Comparison of the Rheological Properties of Heat‐Iiiduced Protein Gels from Egg Albumen and Bovine Plasma. (Lecture).D. W. Hickson, C. W. Dill, R. N. Morgan, V. E. Sweat and Z. L. CarpenterGENERAL PRINCIPLES: A Cell Model Theory of the Shear Viscosity of a Concentrated Suspension of Interacting Spheres in a Non‐Newtonian Fluid.Hideho Tanaka and James L. White.OBJECTIVE MEASUREMENTS: Apparatus for the Measurement of the Mechanical‐Rheological Properties of Gels.F. Horkay, M. Nagy and M. Zrinyi.OBJECTIVE MEASUREMENTS: Experiments For the Determination of the Specific Resistance of Comminuted and Pressed Apple Against Its Own Juice.1. KörmendyFACTORS AFFECTING TEXTURE: Kinetic Analysis of Continuous Yoghurt Fermentation.O. Reichart.FACTORS AFFECTING TEXTURE: Composition of Bioassay Data on the Wholesomeness of Irradiated Food Items.J. Barna.FACTORS AFFECTING TEXTURE: A Relation Between Gluten Protein Amide Content and Baking Performance of Wheat Flours.F. MacRitchie.FACTORS AFFECTING TEXTURE: Quality Attributes of Frozen Okra as Influenced by Processing and Storage.O. C. Aworh, A. O. Olorunda and O. Akibo.FACTORS AFFECTING TEXTURE: Storage Stability of Dehydrated Food—Evaluation of Literature Data.R. Villota, I. Saguy and M. Karel.FACTORS AFFECTING TEXTURE: The Composition, Rheological Properties and Breadmaking Behaviour of Stored Flours.B. M. Bell, N. Chamberlain, T. Hylton‐Collins, D. G. H. Daniels and N. Fisher.FACTORS AFFECTING TEXTURE: The Effects of Pure Saturated and Unsaturated Fatty Acids on Breadmaking and on Lipid Binding, Using Chorleyw ood Bread Process Doughs Containing a ‘Model Fat’.B. M. Bell, D. G. H. Daniels and N. Fisher.RELATIONSHIP TO STRUCTURE: Electron Microscopy Study on the Crystallization Racemes in Fat Globules During the Ripening of Cream.W. Buchheim and D. Precht.RELATIONSHIP TO STRUCTURE: Electron Micraecopic Studier on the Physical Structure of Spreadable Fate 1. The Micro‐Structure of Fat Globules in Butter.D. Precht and W. Buchheim.RELATIONSHIP TO STRUCTURE: The Submicroscopic Structure of Heat Coagulated Milk.A. M. Knoop and K. E. Peters.RELATIONSHIP TO STRUCTURE: The Different Development of the Structure in Harzer, Tilsit and Camembert cheese During Ripening.A. M. Knoop

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1981.tb00539.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY