الفهرس 
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Abstract
Grapefruit sources of vitamin C and potassium and good source of iron, calcium, and other minerals. Pink and red varieties are high in betacarotene, a precursor of vitamin A. High in fiber, low in calories, Contain bioflavonoids and other plant chemicals that protect against cancer and heart disease.
The aim of this study was to investigate the effects of storage on those components, and through the following: To identify the chemical constituents of the fruits of grapefruit when combined directly, to identify the content of grapefruit flavonoids and vitamins and the effect of storage on those components, Examine the level of concentrations of antioxidants found in different parts of the fruits of grapefruit, compared to the levels required to maintain public health and Study the evolution of different chemical components in different parts of the fruit during storage at different temperatures.
Fruits were cleaned, washed with current fresh water and then air dried at roomtemperature. These fruits were stored either at room temperature (22± 2°C) or at refrigerator temperature (4±2°C) for different periods depending on the condition of fruits during the storage. Samples of fruits from each cultivar were randomly taken to determine the physical properties of the fruits. Samples of fruits were taken every week to determine:
Physical properties of fresh fruits in terms of fruit weight; peel weight; pulp weight and juice weight and Chemical composition of fresh fruits in terms of moisture content; sugar contents; protein contents; fat contents; and fiber contents. The PH values; total soluble solids (TSS, °Brix) tiratable acidity %; ascorbic acid content; and the TSS \ acidity ratio of the juice were determined.
The obtained results of the present study could be summarized in the following points:
1- Data revealed that the Marsh cultivar showed 12.42, 12.78, and 9.78 % dry mater in peel, pulp and juice, where as the Duncan cultivar showed 12.62, 10.65, and 7.65 % for the same components which Marsh showed higher than Duncan.
2- Data also revealed that the Marsh cultivar had 24.48 and 35.29 % as total sugars in the peel and in the pulp, while as the Duncan cultivars showed 22.35 and 35.31 %, The non-reducing sugars, however, represented the most dominant sugars in the total sugars, being higher in the pulp than in the peel. The Marsh cultivar had 16.59 and 30.44 %, while the Duncan cultivar showed 16.32 and 26.48 % in peels and pulps, while the Marsh cultivar contained 7.89 and 4.85 and the Duncan cultivar contained 4.36 and 8.83 % reducing sugars in peels and pulps.
3- Data also revealed the Duncan cultivar showed higher protein content than the Marsh cultivar in both peels and pulps. Duncan cultivar had 18.48 and 23.38 % protein, where as the Marsh cultivar showed 14.33 and 20.89 % in peels and pulps.
4- Both cultivars, showed little fat contents as compared to other contents. The Marsh cultivar had 2.09 and 3.7 % and the Duncan cultivar had 2.38 and 3.90 % in both peels and pulps.
5- The fiber contents in both cultivars represented the most dominant component in the dry matter as compared to the other components such as sugars, proteins and fats. However, the Marsh cultivar showed higher content than Duncan cultivar.
6- Data also showed that the Marsh cultivar had a higher content of total soluble solids (TSS) than Duncan cultivars. The juice of Marsh had 10 0Brix compared to 8 0Brix in juice of Duncan cultivar. The PH value and the total acidity % in Marsh juice were 3.29 and 2.21 % compared to 3.4 and 3.37 %
7- Data also revealed that Marsh cultivar showed higher contents of ascorbic acid in peel, pulp, and juice than in Duncan cultivar. Nevertheless, the juice had the highest ascorbic acid content as compared to peels and pulps in both cultivars. The Marsh peels, pulps and juice contained 30.66, 35.33 and 60.02 mg / 100 ml juice as compared to 25.33, 30.36 and 55.65 in Duncan.
8- Data revealed that the fresh fruit weights of both cultivars decreased in similar way as the storage time increased. The fresh fruit weights of Marsh cultivar decreased at the start of storage whereas the Duncan cultivar decreased grams at the end of storage for six weeks at temperature room. The fresh weight of both cultivar decreased by approximately the same percentage 37.97%. Data revealed that the fresh fruit weights of both cultivars decreased in similar way as the storage time increased (temperature room, 40C).
9- Data also revealed that the fresh weight of peel from both cultivars stored at room temperature and 40C also decreased in similar way as the storage time increased