Why ketchup is thixotropic?
Ketchup is a thixotropic fluid which is classified as a non-Newtonian fluid which has property of becoming a liquid like state when force is applied and returns to gel like state without force. The thick viscous consistency of ketchup comes from the pectin in the tomato.
What are the properties of ketchup?
The main quality parameters of ketchup are color, flavor and flow properties.
Is ketchup a thixotropic and pseudoplastic?
Some thixotropic fluids return to a gel state almost instantly, such as ketchup, and are called pseudoplastic fluids. Others such as yogurt take much longer and can become nearly solid. Many gels and colloids are thixotropic materials, exhibiting a stable form at rest but becoming fluid when agitated.
What is an example of a thixotropic material?
Other examples of thixotropic fluids are gelatine, shortening, cream, xanthan gum solutions, aqueous iron oxide gels, pectin gels, hydrogenated castor oil, carbon black suspension in molten tire rubber, many floc suspensions, and many colloidal suspensions.
What kind of fluid is ketchup?
non-Newtonian fluid
Ketchup, in addition to being an exceptionally popular condiment, is also a non-Newtonian fluid. This is the key to its curious behavior. As a non-Newtonian fluid, ketchup’s viscosity — and consequently its ability to flow — varies with the velocity gradient across the fluid or the shear rate.
What is thixotropic fluid?
A thixotropic fluid is one that takes a fixed time to return to its equilibrium viscosity when subjected to abrupt changes in shear rate. In other words, the liquid becomes less viscous (thinner or flows more easily) when shaken, stirred, agitated or otherwise stressed.
What properties of ketchup make it difficult to pour?
This is because the ketchup is acting more like a solid than a liquid. Scientists actually call ketchup and fluids like it “soft solids” or “yield stress fluids” because they only flow when the right amount of force is applied.
What kind of matter is ketchup?
Like toothpaste and paint, ketchup is a “soft solid” or “yield stress fluid” that only moves when the right amount of force is applied. The sauce is actually a suspension of pulverized tomato solids in a liquid.
Is ketchup a fluid?
But tomato sauce prefers to be in the bottle because it is technically a solid, not a liquid.” Like toothpaste and paint, ketchup is a “soft solid” or “yield stress fluid” that only moves when the right amount of force is applied. The sauce is actually a suspension of pulverized tomato solids in a liquid.
What is thixotropic behavior?
In rheology thixotropic behavior is defined as time-dependent behavior. It means a reduction of the structural strength during a constant shear load phase and a more or less rapid but complete regeneration of the structure during the subsequent rest phase.
What makes a material thixotropic?
Materials that are thixotropic have a time-dependent, shear-thinning viscosity. In other words, as the material is placed under stress to flow, the longer the stress is applied, the lower the viscosity will be. Thixotropy can be quantified as the “thixotropic index” of a material.
Does ketchup have viscosity?
So now you know that ketchup is non-Newtonian with a changeable viscosity. It also helps to think of ketchup as a soft solid: a liquid with a bunch of stuff suspended in it. Those suspended bits that compose the ketchup form a network that doesn’t really want to leave the bottle.
Is the viscosity of ketchup really thixotropic?
Over time, the viscosity drops, so yes, ketchup is thixotropic. I would have loved to have taken the data for this last plot, but I have the wrong type of rheometer for it [3], so I am borrowing a plot from TA Instruments.
Which is an example of a thixotropic material?
A well-known thixotropic material is ‘ketchup’. Stirring ketchup turns it from solid-like state to liquid-like state, and if left at rest it recovers its original viscosity.
What kind of fluid is ketchup made of?
Ketchup (or catsup) is a thixotropic fluid made from tomatoes. The property of thixotropy is familiar to all users of ketchup, and is caused by added starch.
What makes ketchup viscous when you add starch?
Ketchup (or catsup) is a thixotropic fluid made from tomatoes. The property of thixotropy is familiar to all users of ketchup, and is caused by added starch. That is to say, it becomes less viscous when agitated.