الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Bananas are one of the best sources of potassium; a medium-sized banana provides 350 mg of potassium. Potassium is an essential mineral for maintaining normal blood pressure and heart function, plus, potassium helps the body maintain normal fluid and electrolyte balances in the cells.
The total production of bananas 119,833,677 million tons in 2020, Potato (Solanum tuberosum L.) is a source of both food and income in the growing countries of the world which able to change greatly the food security of countries because of its high productivity per unit area and time compared to other crops. It is a good source of essential protein, vitamins and minerals. Potatoes also contain dietary antioxidants, which may play a part in preventing diseases related to ageing, and dietary fiber, which benefits health.
The total world production of potatoes in 2020 was 359,071,403 million tones, accounting for 26.3% of world production.
This investigation introduced the construction, operation, and the test results of a solar drier construction and dimensions: Solar collector, the absorber plate of the collector is a black painted galvanized steel sheet of dimensions (2m in length and 1m in width). It was painted with a mat black paint in order to increase its absorptivity. The collector glass cover is a single glass cover with thickness of 0.6 cm and its frame made from an aluminum sheet. The distance between the glass cover and the absorber plat was of 6 mm along the collector was used as an insulating, which made the air passage. Glass wool material for all collector sides. The body of the collector was made from galvanized steel sheets; collector air vent was covered by wire mesh. It was investigated with a fixed inclined of 30° from the horizontal and oriented it towards the south direction and Reflective mirrors have been added that move at an angle from (zero to 180) degrees, as they are moved every half hour towards the sun to reflect the heat on the surface of the solar collector and to increase the temperature of the solar collector.
The investigation and experimentation was carried out in Department of Agricultural Engineering, Faculty of Agriculture, Ain Shams University, Shubra El-Kheima, Egypt (Latitude 30° 11′ N, Longitude 31° 24′ E).
The conclusions of this investigation are
1. The hourly average available solar radiation during the period of the experimental work was 638.6 W/m2.
2. The moisture content of banana and potato decreased from ”80.333 to 7.48”and ”75 to 6.84” kg/kg respectively for banana and potato slices treated using mirrors.
3. The Page model in this condition proved to be the best for predicting drying behavior of banana and potato treated slice with (R2 = 0.997, SE = 0.0534),(R2=0.999,SE = 0.04) respectively
4. These results showed that the percentage of collector efficiency for the banana and potato experiments ranged from (49.83 to 86.56), (57.60 to 93.52) respectively.
5. The percentage of dryer efficiency ranged (22.42 to 60.43), (35.78 to 45.08) and (34.72 to 43.87) respectively.
6. The results showed that the changes in L*, b*, C and chroma of the untreated dried banana and potato samples changed to the lower level of the treated samples.
7. The activation energy values for the rehydration of Potato and banana slices ranged between (0.214 to 0.752) kJ / mole - k and the Arrhenius equation gives good Plot of the data with R² values of (0.817) to (0.993).