Abstract
Many papers have been published about the nutritive value of polymerized oils using esters of those oils. However, it is still not clear whether esters prepared from polymerized oils have the exact nutritive value of original polymerized oils.
In order to compare the nutritive values of polymerized oils and their esters, soybean and linseed oils were blown with air or nitrogen at 275±5°C for 12 hours and a part was esterified.
The growth of rats fed both the thermally oxidized oil (TO) and the polymerized oil under nitrogen (PO) was less than the growth of those fed original oil, and TO showed lower nutritive value than PO. Ethyl ester prepared from TO depressed more the growth of rats than the original TO, whereas ethyl ester from PO showed almost the same growth with original PO before esteriflcation.
Results indicate that ethyl ester from thermally polymerized oil can be used instead of polymerized oil for the determination of nutritive value, but ethyl ester of thermally oxidized oil can not be used.
