| Abstract: |
this dissertation deals with the changes that might take place during storage of cotton seed, corn and sunflower oils in different bottles. the effect of deep fat trying processes on the characteristics of these stored oils wewe also studied.1 - Storage of fresh oils in different bottles at room tem¬perature. The oil samples were stored for 0 , 30 , 60 , 90 , 120 , 150 ,180 days at room temperature in the following bottles: A - Brown and colorless closed glass bottles. B - White ( opaque ) and colorless closed plastic bottles .The behaviour of the oils during storage was evaluated through various analytical determinations such as acid value or free fatty acids % ( as oleic acid) , peroxide,Iodine and saponifica¬tion values. The free fatty acids (%) and peroxide valus in¬creased while iodine values were decreased. The saponification values were stable during the storage periods in different bottlesThe results indicated that the minimum value of free fatty ac¬ids (1.37%) was recorded after180 days when the corn oil was stored in brown glass bottles while the maximum value ( 1.87%) was noticed in the same stored oil in colorless glass bottles . On the other hand, the free fatty acids of cotton seed and sunflower oils were 1.85% and 2.91% respectively when these oils were stored in brown glass bottles for the same periods. The free fatty acids of cotton seed and sunflower oils were 2.660/0 and 3.41% when these oils were stored in colorless glass bottles for the sameperiod. The proxide values of corn, cotton seed and sunflower oils stored in brown glass bottles for 180 days were 35 .56 , 37.18 and 40.99 meq.Og / kg oil, respectively compared with the same oils stored in colorless glass bottles, which recorded 39.83 ,40.86 and 47.99 meq . 02 / kg oil respectively. The iodine values of the same stored oils in the same storage periods were 100.3 , 98.8 and 90.9 respectively, when these oils were packed in brown glass bottles . The saponification values of corn , cotton seed and sunflower oils stored for 180 days in brown glass bottles were 188.1 , 190.7 and 188.1 , respectively . These oils exhibited the highest values when the oils were stored in colorless glass and white plastic bottles. So , the previous results give an idea about how must the oil be stored . This should be done in brown glass bottles and if this is not available, white ( opaque) plastic bottle can be used putting in consideration that bottles must be filledto avoid the effect of the oxygen of the headspace . Brown glass bottles and white ( opaque) plastic bottles gave fairly good protection , whereas the colorless glass and colorless plastic bottles gave the poorest protection to the three mentioned oils from oxidative deterioration when stored at room tempera¬ture . Corn oil is more stable than cotton seed oil which is more stable than sunflower oil.
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