Guar solution

D. Craig and S. A. Holditch. The degradation of hydroxypropyl guar fracturing fluids by enzyme, oxidative, and catalyzed oxidative breakers Pt 1 Linear hydroxypropyl guar solutions Topical report (February-December 1991). Gas Res Inst Rep GRI-93/04191, Gas Res Inst, December 1993. 

Clark, P.E. Halvaci, M. Ghaeli, H. "Proppant Transport by Xanthan and Xanthan-Hydroxypropyl Guar Solutions Alternatives to Crosslinked Fluids," SPE/DOE paper 13907, 1985 SPE/DOE Low Permeability Gas Reservoirs, Denver, May 19-22. 

Ben-Kerrour L, Duchene D, Puisieux F, Carstensen JT. Temperature-and concentration-dependence in pseudoplastic rheological equations for gum guar solutions. Int Pharm 1980 5 59-65. 

In an earlier work [27], several enzymes (lipase, hemicellulase, and protease) were shown to have noticeable effects on the viscosity of guar solutions. Guar typically contains more than 80% soluble galactomannans, 7% proteins, 2-3% fatty acids, and small amoimts of insoluble galactomaimans and cellulosics [28]. 

In Fig. 23, the Bird-Carreau model is compared to the experimental data of a 1.0% guar solution in the frequency/shear rate range of 0.1 to 100 sec . 

FIG. 23. Comparison of predictions of the Bird-Carreau constitutive model and experimental data for 1% guar solution (Kokini et al., 1984). 

I do not remember the exact figures. In general, guar solutions are approximately four times as viscous as solutions of cornstarch at equal concentrations. 

Figure 2.17 Viscosity (rj) of a guar solution as a function of shear rate (y)...

Meat cooking, packaged ham pasteurization disinfestation of fruits liquid food heating (starch solutions, guar solutions)and pasteurization (milk, fruit juices)... 

We can take a closer look at the protease reaction. The use of different proteases gives somewhat different results. For exanq)le, three proteases (Thermolysin, subtilisin Carlsberg, and Alcalase ) all react with cationic guar. However, in an aqueous reaction, Alcalase was found to be the most reactive (Table 2). Up to 95% of the protein could be removed, and there was no significant change in its physical properties. A bonus was a 50% decrease in the turbidity of the guar solution after treatment. 

Fig. 4.23. Viscosity of 1% aqueous guar solution at 25 °C versus shear rate (rpm.). Viscometer Haake ro-tovisco (according to Whistler, 1973)...

Figure 9.14 Dp of (O) 20 and (0)70 kDadextrans in 2 MDaaqueous guar solutions as functions of guar concentration, based on measurements of Cheng, et aZ.(24).

Static headspace analysis of ethyl butyrate release was carried out on the seven guar solutions containing 10% sucrose. Two milliliters of sample was incubated at 37°C in a sealed 10-mL glass vial and agitated at 750 rpm for 10 min using an automated headspace unit (Combipal-CTC Analytics, JVA Analytical Ltd., Dublin, Ireland). One milliliter of equilibrated headspace was injected and analyzed by gas chromatography with flame ionization detection (GC-FID). Analyses were carried out in triplicate. 

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