Viscous dressings

At Kraft Foods, we have had occasion to use this rapid sandwich technique on unembedded cream cheese, viscous dressing and ice cream mix, looking for xanthan or guar/LBG. We have also probed sections of embedded materials for xanthan. In other words, the rapid and embedded techniques are fully complementary. 

The physical properties of barrier dressings were evaluated using the Seiko Model DMS 210 Dynamic Mechanical Analyzer Instrument (see Fig. 2.45). Referring to Fig. 2.46, dynamic mechanical analysis consists of oscillating (1 Hz) tensile force of a material in an environmentally (37°C) controlled chamber (see Fig. 2.47) to measure loss modulus (E") and stored modulus (E ). Many materials including polymers and tissue are viscoelastic, meaning that they deform (stretch or pull) with applied force and return to their original shape with time. The effect is a function of the viscous property (E") within the material that resists deformation and the elastic property (E )... 

Porcine tissue possesses a tan Q of 0.20 or a ration of viscous/elastic property of 1 5, representing good extension and elastic properties. A material that adheres to the tissue must have a similar tan 6 or it will not strain (stretch, pull, flex, etc.) with the tissue and crack until it loses adhesion and disbonds from the tissue, failing as a barrier dressing. 

Rheological properties of mayonnaise have been studied using different rheological techniques steady shear rate-shear stress, time dependent shear rate-shear stress, stress growth and decay at a constant shear rate, dynamic viscoelastic behavior, and creep-compliance viscoelastic behavior. More studies have been devoted to the study of rheological properties of mayonnaise than of salad dressings, probably because the former is a more stable emulsion and exhibits complex viscous and viscoelastic rheological behavior. 

Paredes et al. (1988) found commercial bottled salad dressings to be more viscous than dressings prepared from dry mixes. The Arrhenius activation energy of flow for the commercial dressings ranged between 10.5 and 20.5 kJ/mole. Thixotropic behavior at a constant shear rate was described better by the Weltman equation (Equation 5.33) than the equation of Hahn et al. (Equation 5.34). 

The serving size for viscous (spoonable) dressings remains one tablespoon. Here, too, fat free requires less than 0.5 g of fat per serving. Therefore, a fat-free viscous dressing product may contain about 3% oil or fat in the formulation. 

SWP is a bland, white creamy low viscous sodium-salt of a soluble wheat protein isolate. By its unique combination of functional properties like emulsifying capacity, gelling, binding, and water-retention, the product can be used in several food applications like meat-preparations, soups, sauces, dressings, imitation dairy, etc. It can also be combined with other functional proteins like caseinates, soy isolates, and may result in all types of synergies. 

The classification of the tars is carried out mainly in reference to the equiviscous temperature (EVT). According to BS 76 (1974), there are eight different tar types, from 30 C to 58°C EVT. EVT is the temperature in which 50 ml of tar has a flow time of 50 s when passing through the 10 mm hole of the tar viscometer. As a consequence, the higher the EVT, the more viscous the tar is. Tar with 50°C-58°C EVT is suitable for dense bituminous mixtures in heavy traffic volume sites, whereas tar with 30°C-38°C EVT is used in open graded bituminous mixtures for low traffic volume sites. Tar with 34°C-46°C EVT is usually used for surface dressings. 

The tube consists of synthetic polymers such as fluotinated ethylene propylene (FEP) or polyurethane (PU). For infusion of viscous fluids such as blood and for rapid infusimi cannulas with diameters of 14—16 G have to be used. Smaller size diameters (18—24 G) of catheters are suitable for continuous and intermittent administration of parenteral solutions. Thorough management of the device (e.g. flushing, dressing, daily inspection) reduces complications (e.g. phlebitis) caused by a peripheral access. The need to replace the cannulas routinely is debated. 

The next degree of viscosity includes extremely viscous materials such as face creams, some salad dressings, and epoxy and other types of resins. These can be sampled in the same way as lubricating oils. Opaque types of slurry are best analyzed by diffuse reflectance. Some industrial... 

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