Concentrated orange juice viscosity

We consider the viscosity data on Pera concentrated orange juice (COJ) of Vitali (Vitali and Rao 1984a, 1984b) to illustrate the exponential model for the effect of soluble solids (°Brix) and insoluble solids (% Pulp) (Tables 2-3 and 2-4). The influence of soluble solids on apparent viscosity at a shear rate of 100 s ... 

Figure 2-10 The Influence of Insoluble Solids on Apparent Viscosity at a Shear Rate of 100 s (Va, lOO) Consistency Coefficient, K, of Pera Concentrated Orange Juice, Data of Vitali and...

Figure 2-12 The Strong Influence of Pulp Fraction on the Viscosity of Concentrated Orange Juice (COJ) and the Relative Viscosity (ijr) of COJ.

Figure 2-14 Applicability of the Arrhenius Model to the Apparent Viscosity versus Temperature Data on a Concentrated Orange Juice Serum Sample (Vitali and Rao, 1984b) is Shown.

Vitali, A. A. and Rao, M. A. 1984b. Flow properties of low-pulp concentrated orange juice Serum viscosity and effect of pulp content. J. Food Sci. 49 876-881. 

Carter, R. D. and Buslig, B. S. 1977. Viscosity and particle size distribution in commercial Florida frozen concentrated orange juice. Proc. Fla. State Flort. Soc. 90 130-132. 

Plant food dispersions such as tomato concentrates and concentrated orange juice are important items of commerce. The viscosity function and the yield stress are two important rheological properties that have received considerable attention. Corrections for slip, due to the formation of a thin layer of fluid next to solid surfaces, in a concentric cylinder viscometer depended on the magnitudes of applied torque and on the shear-thinning characteristics of the dispersion. Mixer viscometers were used for obtaining shear rate-shear stress and yield stress data, but the latter were higher in magnitude than those obtained by extrapolation of flow data. 

Finisher screen openings and concentration methods, were found to affect the rheological properties of tomato concentrates. The apparent viscosity of 65 °Brix concentrated orange juice was strongly influenced by temperature. The dispersed phase plays a major role in the magnitude of apparent viscosity and yield stress, and functional relationships for predicting the properties were developed. 

Composition. Scientific data concerning liquids washed with water from orange juice finisher pulp was first published by Olsen et al. (30). They studied Brix/acid ratios, sucrose, reducing sugars, pH, pectic constituents, turbidity, pulp content, ascorbic acid, viscosity, and flavonoid content of experimental and commercial samples. Characterization of pulp-wash continued with publication of quality data (31), examination of pectic substances (32), microbiology (33), and comparison of pulp-wash with orange concentrate (34). 

Crandall, P. G., Chen, C. S., and Carter, R. D. 1982. Models for predicting viscosity of orange juice concentrate. Food Technol. 36(5) 245-252. 

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