الفهرس 
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Abstract
The present study was carried out to test some natural antioxidant phenolic compounds from grape by-product (white, red, black skin and
white grape seeds) Compared with synthetic antioxidants such as Butylated hydroxytoluene (BHT).
The extracted phenolic compounds were tested as natural antioxidants in more than one experiment conclude chemical and biological evaluation.
Therefore, this study aimed to:
7.1.Chemical evaluation:
1. Preparation three grape varieties skin (white, red and black) and white grape seeds, as provided in season 2010, we used (white Romi, Flame
seedless and black Romi).
2. Determination of chemical composition of grape by –product (skin and seeds) each individual and the fatty acid composition of the white grape
seeds
3. Determination the phenolic compounds and anthocyanin in grape byproduct(
skin and seeds).
4. . The phenolic composition of the grape skin and seeds samples was determined by HPLC.
5. Determination the antioxidant activity of grape skin and seeds by DPPH and Linoleic acid system comparing to synthetic antioxidant (BHT)
6. Measurement of the oxidative stability of sunflower oil at 100 °C by different grape by-products extracts samples in comparing with synthetic antioxidant (BHT).
7.2. Biological evaluation
1. Feeding of albino rats’ on basal diet maintain as the control group, Adding the different percentage of grape by-product powder (2, 4. and 8%) to diet and comparing with synthetic antioxidant (BHT) 200ppm.
2. Recording of organs weight of rats e.g. ( liver, kidney, heart and spleen) at the end of experiment.
3. Determinations of lipid profile, glucose, Liver Enzymes and antioxidant Enzymes.
4. Investigation of histological changes of livers
The results of our investigation can be summarized in the following points:
**Chemical evaluation results:
• Chemical composition of white, red, black grape skin and white grape seeds was as follow: moisture (18.97, 7.28, 18.21 and 8.38%), fat (3.93,
6.42,1.89 and10.38% ), protein (10.146, 6.999, 7.872 and 9.076%),fiber (10.56, 7.335, 9.565 and37.25%), ash (6.35,2.94 , 8.36 and 2.38%
), total Sugar (50.044, 69.016,54.103 and 32.534% ) respectively.
• Linoleic acid was the most abundant fatty acid in grape seed oil. It was about 64.72 %of total fatty acids.
• Total phenolic compounds of white, red, black grape skin and white grape seeds were as follow: (296.27, 511.23, 2070.02 and 2536.5 mg/100g ) respectively.