Abstract
Flow properties of heated cottonseed, beybean and rapeseed oils were measured by Maron-Belner type capillary viscometer. To discuss the correlation between the flow properties and chemical properties of the heated oils, acid values, peroxide values and densities of the oils were also measured. Unheated oils of soybean, cottonseed and rapessed showed Newtonian fluid, but the heated oils (170°C, 5-20 hrs.) of soybean and cottonseed showed non-Newtonian fluid at high shear stress, while the change of flow property of rapeseed oil was very little by heating. Acid values, peroxide values, densities and viscosities were increase along with the increase of heating time. The changes of these chemical properties were largest in soybean oil, then followed by the cottonseed oil. Comparing with fatty acid composition of these oils, soybean oil contains the most unsaturated bonds and rapeseed oil contains the least. From the above results, it may concluded that the flow properties of the oils are in proportional to the changes of the chemical properties and the amounts of unsaturated bonds in the oil molecules.
