Soyab~an oil and palm oil were submitted to heal treatment (170-180°C) as
moderate heat~n9 for short-term (6 hrs.) and long-term (12 hrs.). as well as (220-
230°C) as ext a healing for 6 hrs. to evaluate these thennal effects on physical and
chemical varia les al'1d fatty acids composition and compared to fresh oil ones &
cotton seed oil as control. However, fried palm oil at 170-18OCC for 6 hrs. had no
observed chahges in the all parameter of physicochemical properties and also
salUrated andl~r unsaturated fatty acids content. Nutritif.nal assay of different heatec soya bean and palm oils was carried out. Nine groups of adult Albino rats fed of inoividually diets contained 15% tested oil as
follows: C0I10~ seed oil (control). fresh soya oil (F.S.D.). heated soya oil at <200"C for
6hrs. (H1.S.0!). - for 12 hrs (H2.S D.). - at >20QoC for 6 hrs. (H3.S.0.), fresh palm oil
(F.P.O), heat~d palm oil at <200°C lor 6hrs. (H1.P.D.), - for 12 hrs. (H2. P.D.) and-
at >200°C fO~ 6hrs. (H3.P.O.). respectively. The experimental feeding indicated that
no significantl differences in weight gain, food efficiency, liver weight and tiver
enzymes actiytty (Al T and AST) in rats group fed heated palm oil at>200"C for 6 hrs.,
as well as t9tal lipids. total cholesterol and phospholipids in the serum of rats fed the
same heoted F,il. Therefore, it can be concluded that palm oil was more stable against
the moderate; heating for shor1-lerm. The results indicated also that although, soya oil
had high con~ent of the essential fatty acid (Lenoleic acid), but it was less reslstant
against moderate or severe heating process than palm oil. However. the extra heating
(220-230°C) ~ndlor long-term (12 hrs.) for both soya and patm oils induced high
thermoxid8tiv~ processes and yield measurable products that decreased the nutritive
value of sue, oils and made harmful effect in the liver functions for the experimental
animals.