Editing Guar gum (section)

===Thickening===
One use of guar gum is as a thickening agent in foods and medicines for humans and animals. Because it is gluten-free, it is used as an additive to replace wheat flour in baked goods.<ref>{{cite book|last=Fenster|first=Carol|url=https://books.google.com/books?id=XrCZAgAAQBAJ&pg=PA41|title=Gluten-Free 101: The Essential Beginner's Guide to Easy Gluten-Free Cooking|date=8 January 2014|publisher=Houghton Mifflin Harcourt|isbn=978-1-118-53912-5}}</ref><sup>:41</sup> It has been shown to reduce serum cholesterol and lower blood glucose levels.<ref>{{cite news|url=https://www.drugs.com/npp/guar-gum.html|title=Guar Gum Uses, Benefits & Dosage - Drugs.com Herbal Database|work=Drugs.com|access-date=3 May 2018}}</ref>

Guar gum is also economical because it has almost eight times the water-thickening ability of other agents (e.g., [[cornstarch]]) and only a small quantity is needed for producing sufficient [[viscosity]].{{clarify|reason=for thickening what foodstuffs for people, animals, as well as medicines for both.|date=February 2016}}<ref>{{Cite journal |title=Advanced Food Science II |url=https://core-docs.s3.amazonaws.com/documents/asset/uploaded_file/643462/Mrs.Arnold_Ad._Food_Science.pdf |journal=Advanced Food Science |volume=2 |issue=1 |pages=12}}</ref> Because less is required, costs are reduced.

In addition to guar gum's effects on viscosity, its high ability to flow, or ''deform'', gives it favorable [[Rheology|rheological]]{{clarify|reason=what?|date=July 2016}} properties. It forms breakable{{clarify|reason=explain in what sense are the gels breakable?|date=June 2018}} gels when cross-linked with boron{{citation needed|date=July 2021}}. It is used in various multi-phase formulations for hydraulic fracturing, in some as an [[emulsifier]] because it helps prevent oil droplets from coalescing,{{citation needed|date=July 2021}} and in others as a [[Stabilizer (chemistry)|stabilizer]] to help prevent solid particles from settling and/or separating{{citation needed|date=July 2021}}.

Fracking entails the pumping of sand-laden fluids into an oil or natural gas reservoir at high pressure and flow rate. This cracks the reservoir rock and then props the cracks open. Water alone is too thin to be effective at carrying [[Fracking proppants|proppant]] sand, so guar gum is one of the ingredients added to thicken the slurry mixture and improve its ability to carry proppant. There are several properties which are important 1. [[Thixotropy|Thixotropic]]: the fluid should be thixotropic, meaning it should gel within a few hours. 2. Gelling and de-gelling: The desired viscosity changes over the course of a few hours. When the fracking slurry is mixed, it needs to be thin enough to make it easier to pump. Then as it flows down the pipe, the fluid needs to gel to support the proppant and flush it deep into the fractures. After that process, the gel has to break down so that it is possible to recover the fracking fluid but leave the proppant behind. This requires a chemical process which produces then breaks the gel cross-linking at a predictable rate. Guar+boron+proprietary chemicals can accomplish both of these goals at once.{{citation needed|date=August 2018}}