Study on Trace Elements in Fresh Edible and Home Cooked Egyptian Foods

الباحثين
Ghoniem
Essam Hassan.
سنة النشر 1985

a Trace elements may be found in food from four different sources: 1. Present in food ’as a consequence of natural event. 2. Result from excessive using pesticides and fungicides. 3. Results from using equipments made of these metals. 4. Results from industrial polluted soil and irrigating wat er. Some elements have B nutritional value, e.g. iron, copper, zinc, magnesiumrAll the essential elements become harmful at inbalance intake. Other elements have toxico logical significanc e, e. g. cadmi urn, le’ad and mere ury . The foods selected includ food items representing the main food groups constituting the diets commonly consumed. These food sam~les included, vegetables, fruits, protein rich foods and energy rich foods. Edible portion of these foods were analysed both in the fresh and cooked state. Twenty daily diets selected from the 67’aietary records were analysed in the laboratory for trace minerals. The samples were analysed by Atomic Absorption spectrophotometer. Samples were sUbjected to the following :­ 1. Trace elements analysis using the dry ashing procedure for the determination of iron, copper, zinc and magnesium. 2. Heavy metals analysis using the dryashing procedure for lead, cadmium and selenium, mercury was determined by cold vapour atomic absorption method. ). Percent difference between values of determined and calculated trace elements. 4. Contribution of different food groups to daily intakes of trace elements. 5. Distributions of the subjects according to levels of daily trace elements intakes. 6. Coefficients of correlations between protein and energy contents of the diets and trace elements. Data obtained indicate that: 1. The iron contents of fresh vegetables and fruits showed a very wide range of variation. It ranged between ~ 6 - 281. 5 ug/.gn4 of the ami mal foods, eggs contained the highest levels ofiron 100 ug/gm. Bread and rice contained relatively small amounts of iron 19.0 and 12.0 ug/gm. 2. Copper occuredatR~uch more sma~quantities in the same foods compared to iron. Foods rich in iron contained the relatively high levels of copper. J. Zinc contents of fresh vegetables showed less variations in iron and copper. 4. The calculated values of trace elements were higher than the values obtained by laboratory analysis, the differences were high for heavy metals. 5. The amounts of iron, copper, zinc, cadmium in the daily diets were affected by the amounts of animal foods in the diet. While selenium and magnesium were affected by amounts of bread and sereals. 6. There are a significant correlations between protin energy and iron, copper and selenium content in the diet. 
a Trace elements may be found in food from four different sources: 1. Present in food ’as a consequence of natural event. 2. Result from excessive using pesticides and fungicides. 3. Results from using equipments made of these metals. 4. Results from industrial polluted soil and irrigating wat er. Some elements have B nutritional value, e.g. iron, copper, zinc, magnesiumrAll the essential elements become harmful at inbalance intake. Other elements have toxico logical significanc e, e. g. cadmi urn, le’ad and mere ury . The foods selected includ food items representing the main food groups constituting the diets commonly consumed. These food sam~les included, vegetables, fruits, protein rich foods and energy rich foods. Edible portion of these foods were analysed both in the fresh and cooked state. Twenty daily diets selected from the 67’aietary records were analysed in the laboratory for trace minerals. The samples were analysed by Atomic Absorption spectrophotometer. Samples were sUbjected to the following :­ 1. Trace elements analysis using the dry ashing procedure for the determination of iron, copper, zinc and magnesium. 2. Heavy metals analysis using the dryashing procedure for lead, cadmium and selenium, mercury was determined by cold vapour atomic absorption method. ). Percent difference between values of determined and calculated trace elements. 4. Contribution of different food groups to daily intakes of trace elements. 5. Distributions of the subjects according to levels of daily trace elements intakes. 6. Coefficients of correlations between protein and energy contents of the diets and trace elements. Data obtained indicate that: 1. The iron contents of fresh vegetables and fruits showed a very wide range of variation. It ranged between ~ 6 - 281. 5 ug/.gn4 of the ami mal foods, eggs contained the highest levels ofiron 100 ug/gm. Bread and rice contained relatively small amounts of iron 19.0 and 12.0 ug/gm. 2. Copper occuredatR~uch more sma~quantities in the same foods compared to iron. Foods rich in iron contained the relatively high levels of copper. J. Zinc contents of fresh vegetables showed less variations in iron and copper. 4. The calculated values of trace elements were higher than the values obtained by laboratory analysis, the differences were high for heavy metals. 5. The amounts of iron, copper, zinc, cadmium in the daily diets were affected by the amounts of animal foods in the diet. While selenium and magnesium were affected by amounts of bread and sereals. 6. There are a significant correlations between protin energy and iron, copper and selenium content in the diet.