ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00355.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The paper describes a procedure and an equation to calculate the absolute rigidity modulusGof materials which undergo barrel shape deformation when compressed by an Instron. Values forGof gelatine‐Alginate and casein‐alginate gels were determined over the pH range of 2.6‐9.6. The rigidity modulus of these gels after freezing and thawing were then compared. The swelling behaviour of these gels at various pH values were also

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00356.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

The perceived in‐mouth thickness (T) of a range of fluid foods and model systems was assessed by a trained sensory panel, using a ratio scaling technique, and correlated with objective measurements of viscosity (ηN). For Newtonian samples a simple linear correlation (r2= 0.98) is observed between logTand log η with exponent η= 0.22. The linear relationship between logTand log η for Newtonian materials was used to calculate the equivalent Newtonian viscosity (ηN) from subjective panel scores for the non‐Newtonian samples studied. The shear rate at which observed viscosity is equal to ηNdecreases with ηN, as reported previously by Shama and Sherman, but also decreases with increasing shear‐rate dependence of viscosity. This implies oral perception of viscosity over a range of shear rates. Comparison of flow curves for samples assigned similar thickness scores, but showing very different shear thinning behaviour, suggests that the perceived thickness of extremely shear‐thinning materials is dominated by their high viscosity at low rates of shear. As a simple practical index, viscosity at 10 s−1shows a better correlation (r2= 0.95) with the perceived thickness of the samples studied than values calculated by the methods suggested by Wood, or by Shama and Sherman (r2= 0.90 in both cases). The close agreement between panel scores for perceived thickness and perceived stickiness previously observed for concentrated solutions of random coil polysaccharides does not apply for several of the food systems studied, or for very concentrated solu

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00357.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Viscoelastic properties of groundnut oil‐in‐water emulsions stabilized by egg yolk and of mayonnaise have been deduced from their creep compliance‐time response to a constant low shear stress. The viscoelastic parameter values, emulsion stability and initial mean drop size were influenced by pH and NaCl, due to disruption of the egg yolk components. When carboxymethylcellulose was incorporated in the continuous phase of the O/W emulsions an egg yolk‐carboxymethylcellulose complex was formed and this affected the rheological properties of the emulsions and also their stability. Mayonnaises exhibited more pronounced viscoelasticity and greater stability than the O/W emulsions. At elevated temperature the micelles adsorbed around oil drops degrade. Their lipoprotein structure unfolds so that more segments on adjacent drops are then available for interlinking and network fo

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00358.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

An instrument has been developed to measure the hardness of fat on sides of chilled beef. A 0.97 mm diameter cutting pin, 3.76 mm long, is inserted perpendicular to the subcutaneous fat and moved through the fat a fixed distance in a direction parallel to its surface by a pretensioned spring. The time for the pin to travel this distance is measured electronically. Times are recorded for the pin to travel through both air and fat and the average force to cut through the fat is then calculated from these readings. There was a linear relationship between the average force resisting the pin travel and the subjective ratings of fat hardness by five experienced boning room personnel. The instrument offers a simple, rapid and portable method of measuring fat hardness in abattoirs.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00359.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Time dependent flow properties of commercial mayonnaise have been measured at shear rates of 0.530, 0.169, 0.052, and 0.0169 s−1. The flow curves were fitted with a series of two first order rate functions. It appears that the time dependent flow properties of mayonnaise are better characterized by this model than with only the initial and final stress values of the stress decay curves or with a single first order rate functio

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00360.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Colloid and Interface Chemistry.Robert D. Vold and Marjorie J. Vold.Food Research and Data Analysis.H. Martens and H. Russwurm, eds.

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00361.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

ISSN:0022-4901    

DOI:10.1111/j.1745-4603.1983.tb00354.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY