In life, we know that there will always be conditions where material flows or deforms in response to applied pressure. One of the branches of physics that studies changes in the shape of this material is rheology. This science studies rheological properties in which the ability to flow is not only possessed by gases and liquids but also solids that have different levels. What was said by the Greek philosopher, Heraclit that all objects’ flow is seen in the rheological properties studied so far?
Food technology uses rheology as a reference to direct the flow of food products, both liquid, and solid foods. Another industry that is also concerned about the rheological properties of a material is construction. A construction worker must estimate the length of work on the asphalt road surface after knowing the side deformation that occurs periodically from time to time.
This is the rheological property of flowing solid objects that can be affected by temperature so that the asphalt changes shape more quickly when traffic occurs on it. Many industries are sure to find these rheological properties. This is an obstacle that must be taken seriously. Controlling the rheological properties of dispersion is part of the industry itself, and there must be a manufacturer who makes special material to cope with it.
Material Deformation
All objects must have a deformation condition where this is the way the object responds to a given force or pressure. The most common form of deformation is strain. Material may be subjected to shear strain. This strain model is common inflow along the tube.
A new strain occurs when there is a pressure or force, which is an energy per unit volume of fluid material. The viscous liquid is the response to the rate of deformation. There is also a material that is viscoelastic where there is ab instant and delayed combination response to the applied pressure. Particle cells, droplets, and polymer chains are components that interact with each other in the fluid, giving rise to viscoelasticity. Liquids having shear diluent properties will be very effective in controlling the rheological properties of dispersion.
Rheology for the Food Industry
The food industry is in dire need of controlling rheological properties of dispersion to maintain the consistency and flow of food by strictly defined conditions. Food rheology is important to know how stable the texture of the food is, how long the shelf life of food is, and how the food can withstand all the conditions around it.
However, consumers always want the food they receive in very good condition with a pleasant texture, softness, and easy to consume. Based on their rheological state, foods can be grouped into solids, liquids, gels, and emulsions with associated rheological behavior and measurable rheological properties.
To help entrepreneurs in the food industry, chemical manufacturers made a breakthrough in controlling the rheological properties of dispersion by creating several types of thickening agents. It is a substance that can be added to an aqueous mixture to increase its viscosity without changing any other properties like taste and scent. The thickening agent can also be a gelling agent to thicken and stabilize suspensions of emulsions and liquid solutions.
Cellulose ether products are one of the materials that are often used by the food industry as a food thickener. Not all food entrepreneurs use food thickeners such as polysaccharides and protein. Polysaccharides are starch, vegetable sap, and pectin. If the product is very high, food manufacturers prefer cellulose ether products to minimize the collection time of natural polysaccharides and speed up the processing of the products.
Interface Rheology
Compositional irregularities often lead to diseases such as dry eye syndrome and infant respiratory distress. Protein production is associated with surfactants in neonatal infection as well as dry eyes. This is a condition in which the eye doesn’t produce enough tears or tears evaporates too quickly.
Dry eye conditions can occur due to the use of certain drugs such as antihistamines, hormone replacement therapy drugs, blood pressure medications, antidepressants, use of contact lenses, vitamin A deficiency, pregnancy to meibomian gland dysfunction. Dryness of the cornea accompanied by burning, itching, soreness, and fatigue can be overcome by giving false tears. It’s dependent on controlling rheological properties of dispersion where the interface viscoelasticity is needed.
In the food industry, interface rheology is important to understand texture stability in espresso foam, a film in black tea, kombucha biofilm formation, and emulsion stability in mayonnaise.