Rheology of Muffin Batters by Line Spread Test and Viscosity Measurements
This work was aimed to quantify the flow properties of muffin batters by Line Spread Test (LST) and to establish a valid correlation between their line spread distance and viscosity. LST is a quick and inexpensive method for comparing relative viscosities of food slurries or a solid-liquid suspension type of food materials, like muffin batters. The rheological proper ties of muffin batters formulated using gluten free flours were studied. Five different combinations of rice flour and quinoa flour were studied as gluten free flour combinations. Control muffin batters were formulated using 100% wheat flour, which is a gluten positive flour. Density, pH, line spread distance and viscosity were measured for all six batter formulations including control. All tests were performed in triplicate and all data were analyzed statistically. In general, gluten free flour reduced the density and increased the acidity of muffin batters. Whereas, line spread distance was increased and viscosity was decreased with replacement of quinoa flour to rice flour in the muffin batters. A valid correlation between line spread distance and viscosity was observed. The inverse of LST in cm/sec was observed to be close to the viscosity in poise for muffin batters in this study.
Categorization of dysphagia diets with the line spread test.
OBJECTIVE
To categorize dysphagic diets according to the food's viscosity, as determined by an objective method.


DESIGN
Description of dysphagic diet in terms of viscosity.


SETTING
Food science laboratory at a university hospital.


SPECIMENS
Twenty kinds of foods: 10 commercially available and 10 formulated for a dysphagic diet in a tertiary university hospital, representing a wide range of food viscosities.


INTERVENTIONS
Not applicable.


MAIN OUTCOME MEASURES
Viscosity, measured with a viscometer, and a line spread test (LST).


RESULTS
Logarithmic viscosity (centiPoise [cP]) values measured using a viscometer were inversely correlated with the extent of spread (centimeters) on an LST. (Pearson r=-.95, P=.0001). Viscosities and the LST results were 0.9+/-0.1cP and 5.5+/-0.5cm for water, 63.1+/-4.8cP and 3.4+/-0.1cm for the barium solution, 671.0+/-76.9cP and 2.4+/-0.1cm for yogurt, and 10,031+/-728cP and 1cm for pudding.


CONCLUSIONS
Dysphagic diets can be categorized according to their viscosities by objective measurements. The LST correlated well with viscometer measurement and is a practical method with which to measure viscosity.
Preparation and performance evaluation of swine manure bio-oil modified rubber asphalt binder
Abstract In order to study the effect of the preparation process of swine manure bio-oil modified rubber asphalt binder on the rheological properties of the binder, the matrix asphalt and asphalt rubber were used as the control group, and swine manure bio-oil modified rubber asphalt binders were obtained by three preparation processes. Then the rheological properties of five binders were evaluated by rotational viscosity, DSR, MSCR and BBR tests. The results show that the addition of swine manure bio-oil to asphalt rubber is beneficial to the workability, but cause negative effect on its high temperature performance, fatigue performance and low temperature crack resistance. The preparation method of premixing bio-oil and rubber powder can reduce the degradation of high-temperature performance of asphalt rubber caused by addition of swine manure bio-oil to a certain extent. The fatigue properties of the three bio-binders are close, and the critical temperature is less than 25 °C. The process of premixing bio-oil and rubber powder will increase the creep stiffness and reduce the low-temperature performance. However, the low-temperature performance of the binder obtained by this process is still better than that of the matrix asphalt and can meet the requirements of use. Therefore, it is recommended to use the preparation process of premixing bio-oil and rubber powder to prepare swine manure bio-oil modified asphalt rubber.