Firmness, apparent viscosity
, WHC, and syneresis from yoghurts produced utilizing milk from three different species (sheep, cow, and goat) are presented in table 5.
where [[eta].sub.a] (Pa s) apparent viscosity
at a given shear rate, [[eta].sub.0] (Pa s) zero-shear viscosity, Ea (J/gmol) activation energy of flow, R (J/gmol K) constant of gases,T (K) absolute temperature, a (-), b (K), c (K2), [a.sub.1] (-) and [a.sub.2] (L/g) are constant and C (g/L) concentration of total solids.
A best-fit ([R.sup.2] = 0.98) semiempirical expression for apparent viscosity
was determined with the inline rheometer based on measured pressure drop which assumes the validity of the linear correlation observed by Bond.
Suspensions of water contents below 40 vol.% presented high levels of apparent viscosity
([eta], Figure 6) due to two mains effects.
The power law model (see (1)) was used to predict the variation of apparent viscosity
with shear rate of tomato fiber suspensions.
The apparent viscosity
, shear stress, and shear rate of the slurry fluid with different cation exchange capacities are calculated according to the data obtained from the viscometer and Equations (3)-(5) [39,40], and shear rate obtained is the average value to improve the accuracy:
For evaluating the rheological performance of the prepared paste samples, a Brookfield R/S+ Rheometer was employed to test the shear stress and apparent viscosity
at various temperatures.
Gibilaro, "Apparent viscosity
measurements in a homogeneous gas-fluidized bed," Chemical Engineering Science, vol.
5 that in the case of non-Newtonian oil flow in plane-radial cracks with opening increasing the limiting yield stress and apparent viscosity
of oil are decreased up to certain crack value.
Table 3 shows the apparent viscosity
of the various solutions, according to the Tukey's test, statistically significant differences are found for each material and concentration.
(AV), plastic viscosity (PV) and yield point (YP) Unit of: PV in centipoises (CP), AV in centipoises (CP) and YP in 1b/100 [ft.sup.2] .