Vegetable oils are mainly triacylglycerols (92–98%), polar lipids (phospholipids and galactolipids), monoacylglycerols, diacylglycerols, and minor amounts of free fatty acids and polyisoprenoids.
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How can you reduce the viscosity of cooking oil?
In addition to transesterification, some methods to reduce the viscosity of vegetable oils are dilution, microemulsion, pyrolysis and catalytic cracking [10,12]. In addition, one important issue is that the calorific value of vegetable oil is lower than that of diesel oil.
How do you reduce the acidity of oil?
[6] esterified pyrolysis oil products using acid catalysis to significantly reduce the acid value from 67.0 to 6.0 mg KOH/g. The product (carboxylic acid) can be effectively converted into its corresponding fatty acid ester via esterification for the purpose of lowering the acid value.
What is vegetable oil chemical formula?
The products include 90.96 g(C18H33O2)CH2CH(C18H33O2)CH2-(C18H33O2), abbreviated “GOOO” (M = 885.5 g/mol).
What is viscosity of vegetable oil?
Absolute Viscosities of Vegetable Oils at Different Temperatures and Shear Rate Range of 64.5 to 4835 s.
How does temperature affect the viscosity of vegetable oil?
It has been well established that temperature has a strong influence on the viscosity of fluid products with viscosity generally decreasing with increase in temperature.
How do you remove fatty acids from oil?
In the classical methods of removal of free fatty acids from oils, oil is put into reaction accompanied by an alkali (NaOH, KOH vb.) and thus FFA is transformed into soap and removed.
What is the acid value of vegetable oil?
The acid values obtained in this study were 2.728 mg KOH/g for the locally made oils and 0.999 mg KOH/g for the imported oils which showed that both were above the permissible level (0.6 mg KOH/g) [18].
What is the need of esterification of vegetable oil?
Esterification reaction is mostly used for reducing the FFA level of oil and then followed transesterifiaction reaction for converting fatty acid into fatty acid methyl esters. Some of the people are following esterification process for producing fatty acid methyl esters. Biofuels. Biodiesel Production.
Is vegetable oil saturated or unsaturated?
Unsaturated fats are predominantly found in foods from plants, such as vegetable oils, nuts, and seeds. There are two types of “good” unsaturated fats: 1.
Why is vegetable oil nonpolar?
The chemical structure of vegetable oil is seen below: The long fatty acid chains mainly contain carbon- hydrogen bonds which have essentially no dipole moment. Therefore oil is non-polar.
What type of fatty acid is vegetable oil?
The presence of caprylic acid (10.45% ± 0.07%), capric acid (5.8% ± 0.75%), lauric acid (45.63% ± 0.93%), and myristic acid (16.33% ± 2.23%) were detected in all the vegetable oils tested.
What is the characteristics of vegetable oil?
they are greasy to the touch, and have lubricating properties; they are not readily volatile; and may be burned without leaving any residue, i.e., ash.
Is vegetable oil soluble in water?
Oils and fats not have any polar part and so for them to dissolve in water they would have to break some of water s hydrogen bonds. Water will not do this so the oil is forced to stay separate from the water.
How do you increase the viscosity of vegetable oil?
It is known that the viscosity of oils can be increased by additions of finely divided solids. Highly dispersed silica is particularly suitable for that purpose. On the other hand, additions of high-melting fats, for example, hardened glycerides of relatively long chain length, have the same effect.
Does viscosity increase with temperature?
Viscosity generally decreases as the temperature increases. Viscosity generally increases as the temperature decreases. The viscosity of a liquid is related to the ease with which the molecules can move with respect to one another.
How can you change the viscosity of a liquid?
The viscosity of liquids decreases rapidly with an increase in temperature, and the viscosity of gases increases with an increase in temperature. Thus, upon heating, liquids flow more easily, whereas gases flow more sluggishly.
Which of the following oils has the highest viscosity?
Which of the following oils has the highest viscosity? Explanation: Higher the SAE grade, higher the viscosity. Since SAE 50 has 50 grade hence it as highest viscosity amongst the other oils.
Why is cooking oil more viscous than water?
Scientifically, the frictional force that acts between the layers of oil particles(viscosity of oil) is greater than the frictional force that acts between the layers of water(viscosity of water).
Why is viscosity important in cooking oil?
The viscosity of edible oils is a parameter used to describe quality. Liquid viscosity is also important regarding design of process equipment for the edible fat- and oil industry. Rheological data are required for process piping design, pressure drop determination and in design of heat transfer equipment.
How do you neutralize free fatty acids?
Physical refining is to remove free fatty acids by steam distillation. Chemical refining is by neutralizing the FFA with alkali, which is often caustic soda, the chemical reaction creates soap stock, which settles down to the bottom of the tank and removed or separated by centrifugation.
What causes high FFA in oil?
Free fatty acids form during frying due to the presence of moisture in the foods exposed to oil. Normally, 0.5–0.8% FFA is encountered. If the frying rate is insufficient to drive water from food at a sufficient rate, the FFA content increases rapidly. High-FFA frying oil smokes at a progressively lower temperature.
What are free fatty acids in oil?
Free fatty acids (FFA) are produced by the hydrolysis of oils and fats. The level of FFA depends on time, temperature and moisture content because the oils and fats are exposed to various environments such as storage, processing, heating or frying.
What is the pH of vegetable oil?
The pH of neat vegetable oil varied between 7.38 and 8.63 and of WCO between 5.13 and 6.61.
What happens if acid value is high?
An increase or rise in acid value indicates rancidification of the oil [23]. … … The lower the acid value of oil, the fewer free fatty acids it contains which makes it less exposed to rancidification [23]. An increase or rise in acid value indicates rancidification of the oil [23] .