الفهرس 
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Abstract
Oils as a foodstuff are considered sensitive to deterioration during their handling and storage. Common changes may be occurred to oils are oxidation, hydrolysis and rancidity Antioxidants have been added to vegetable oils to slow down the oil oxidation and to extend its shelf-life. It is well known fact that synthetic antioxidants cause various kinds of biological damage, when added to oil Consequently, more attention has been paid for replacing the synthetic antioxidants in food by addition of natural antioxidants !O avoid such undesirable changes in oil.
The present study was carried out to Investigate the antioxidative electiveness of natural anti-oxidants, namely rosemary extract (RME), and white pepper extract (WPE) in compare with that of synthetic antioxidants tertiary butyl hydro quinone (TBIIQ) on the quality of rapeseed oil during stage for six months.
Rapeseed oil was extracted using two species namely Brassica napus and Brassica The erude oils extracted from two species were mixed at the ratio of 4 : 1 (w/w), respectively Extracted oil were divided into two parts, One of them was used as crude original oil and the other was lnreresterified using 1,3 specific lipase at 48°C for 72 hours. Antioxidants were added to original crude and interesterified oils at concentrations of 100 and 200 ppm. The oils were stored in amber and transparent glasses at room temperature for six months The obtained results were summarized as follows:-
1-Bolh species of the extracted oils belong tothe category of mono ethylene fatty acids (Eicoseni and erucic). Physical and chemical properties of the two oil species were nearly the same. Total fatty acid composition was 99. 738 and 99.994 in B napus and B. juncea respectively and arachadic acid represented the high percentage in crude rapeseed oils of both species (16 3S and 25.62%, respectively), The predominant unsaturated fatty acid was erucic add in B. juneu
oil (36,3 1%) and oleic acid was the highest unsaturated fatty acid in B. napus oil (50 58%)
2, Enzymatic interesterification of the oil extracted from two .species of B. naplis and B. juncea was carried out using 1,3 specific lipase at 48ͦ C (pH 7) for 72 hours
Interesterification process has been improved the physical, chemical, and nutritional properties of oil by reducing the amount of harmful unsaturated fatty adds, especially, erucic acid (C22:1) from 12.501 1n original crude oil to 3.541 in interesterified oil. Also, the contents of essential fatty acids, oleic and linoleic were increased from 47.30 to 52.478% and 18.391 to 19287% in OC and 1E, respectively. Also, the process of imeresterification affected Positively on the sensory properties namely, colour, taste and odour.
3. Antioxidative effectiveness of natural and synthetic antioxidants during storage of both original crude (DC) and interesterified (IE) rapeseed oils in amber and transparent glasses were determined and obtained.