ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00648.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00649.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00650.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00651.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractSamples of lard and shortening have been examined by five rheological techniques: cone penetrometer, Ferranti‐Shirley cone and plate viscometer, concentric cylinder creep, creep by spherical indentor and oscillatory testing using the Weissenberg rheogoniometer. The derived data are discussed critically with reference to the measurement of parameters for use in quality control and the development of theories of fat structure based on molecular structure and chemical interaction.Penetrometer and continuous shear viscometer measurements are not recommended. Instead, creep testing (and the calculation of viscoelastic parameters) is suggested for quality control purpose

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00652.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractConcentrated benzene‐in‐water emulsions were prepared with various proteins such as lysozyme, bovine serum albumin, ovalbumin, casein and gluten. The emulsions consisted of coarse globules whose size distribution could be approximated to the log‐normal distribution function, while the adsorbed film of protein molecules seemed to contribute to the stabilization of the globules. These properties were influenced by the pH of the aqueous phase. The mean globule size increased progressively up to the isoelectric point of the proteins. Both the interfacial tension and the rate of coalescence between the globules were minimized as the isoelectric point of the proteins was appro

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00653.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA coherent explanation is presented of the mechanisms by which mixed emulsifiers of the surfactant/fatty alcohol type both stabilise and control the consistencies of oil‐in‐water emulsions. Original and published data are used to develop a theory in which the semisolid and other flow properties of emulsions are related to the nature, strength and extent of viscoelastic networks present in the continuous phases. These networks form from the interaction of surfactant solution with fatty alcohol and have similar properties to ternary system gels formed when the mixed emulsifiers disperse in water, in the absence of an oil.The theory is discussed with particular reference to liquid paraffin‐in‐water emulsions prepared with the surfactants anionic sodium dodecyl sulphate, cationic alkyltrimethylammonium bromides or non‐ionic cetomacrogol and fatty alcohols cetyl and stearyl and their mixtures, especially cetostearyl. It may be used also to explain the properties of emulsions prepared with a variety of oils, surfactants and amphiphiles. The effects of variation in storage time, surfactant type (ionic or non‐ionic), temperature, mixed emulsifier concentration, and alcohol and surfactant chain lengths on the rheological and microscopical properties of ternary systems and emulsions support this theory. The importance of small strain experiments (creep and oscillatory) in providing a true measure of consistency is emphasized. Continuous shear experiments, although theoretically less satisfactory, provide useful additional information when correlated with the small

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00654.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe cone and plate viscosimeter was found applicable to studying the effect of experimental variables on the behaviour of flour doughs. A simple method of analysis based on the use of a power law is proposed. The variables studied were: type of flour, water content, mixing time, temperature and the presence of certain chemical compounds. Based on the results obtained, hypotheses were advanced on the importance of non‐covalent bonds in influencing the rheological properties of dough

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00655.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractFlow properties of several liquid and semi‐solid foods were characterized objectively with a coaxial cylinder viscometer. At the same time, a sensory evaluation panel compared the viscosities of these samples by tilting the containers and also by stirring the contents with a spoon. Correlation of the instrumental and sensory evaluation data established the shear stress‐shear rate conditions prevailing during sensory evaluation of viscosity. The stimulus responsible for viscosity evaluation by tilting the container is the shear rate (0.1–40 sec‐1) developed at a shear stress (60–600 dyne cm‐2) related to the flow properties of the sample, whereas in stirring tests the stimulus is the shear stress (102–104dyne cm‐2) developed at a particular rate of shear (90–100 sec‐1). In the latter type of test, the shear rate varies to some degree with the flow characteristics of the sample. Since different stimuli are involved in viscosity assessment by tilting the container or by stirring, it is possible for a series of samples to be given different ranking orders by the two me

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00656.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe stimulus associated with oral evaluation of the viscosity of liquid and viscous foods appears to embrace a range of shear rates extending from 10‐1to 1000 s‐1.The value associated with a particular food depends on its flow characteristics. For liquid foods the stimulus appears to be the shear rate developed at an approximately constant shear stress (∼ 100 dyn cm‐2), whereas for viscous foods it appears to be the shear stress developed at an approximately constant shear rate (∼ 10 s‐1). Additional factors may be involved when evaluating highly viscous non‐Newtonian foods or foods with an oil continuous medium. These are ‘plug flow’ or the spreading coeffici

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1973.tb00657.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY