Moses, S. C.KUMAR, ASHOK2017-11-132017-11-13http://krishikosh.egranth.ac.in/handle/1/5810035422Ph.d thesisDrying is one of the simplest and oldest methods of preservation of vegetables. As concentration of solids is the dried vegetable become high, water activity reduces greatly; product becomes chemically stable and free from insect, pest attack and mould, yeast growth during storage. Use of solar energy for drying application is gaining- importance because of growing realization of pollution free nature of renewable energy. But the direct use of the solar energy as a drying energy for the drying of vegetables, fruits and other small plants is not convenient, because it require more time and the ingredient values of them has affected by direct sun light and the drying process is also not universal. So overcome of these problems many researchers had designed and fabricate several solar dryer in the past and these dryer have many advantages and disadvantages. In this, a modified and high efficient solar tunnel dryer has developed and fabricated and also evaluated it for five samples (potato, onion, pineapple, methi and mint) at various sites being developed and fabricated in the farm machinery labs, SHUATS, Allahabad. Developed solar tunnel dryer have many component. Such as semi cylindrical tunnel, main frame, frame base, solar collector, dryer, trays, air inlet and outlet, wire mesh sheet and fan system. After the fabrication of the solar tunnel dryer, the performance evaluation was carried out by many means and quantities for the five samples. For this purpose, each sample have taken and dried for the six days and observed the value of temperature rise (θ), change in humidity of the drying chamber by the inlet and out air, reduction in the moisture value and also find out the drying rate of the solar tunnel dryer which was found as maximum 25.5oC and minimum 2.2o C rise temperature. Due to this rise temperature,ennullThesis