الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Experiments were carried out through summer 2013 in the rice mechanization center at Meet El-Dyba, Kafr El-Sheik Governorate, Egypt. In order to determine the proper conditions for drying peppermint (whole plants and leaves) under using tunnel greenhouse type as a solar dryer compared with traditional sun drying. The objectives of this work are to: 1.Drying peppermint plants in order to obtain the best quality of dried peppermint with the least drying time. 2.Study the effect of different operational parameters on drying peppermint plants using two different drying methods. 3.Predict the thermal performance of drying behavior by carrying out a theoretical analysis. 4.Evaluate the drying process from the economic point of view. Experiments were conducted under the following variables of two different drying methods (solar tunnel greenhouse dryer-traditional sun drying), two different plant conditions (whole plants and leaves), three different loads (2, 4and6) kg / m2, three different air velocities (0.5, 1 and 1.5 m/s) represented air flow rates of 1.05, 2.1 and 3.15 m3/min and two different systems of fan operating (continuous and periodical). Experimental results revealed that drying rate, drying efficiency, volatile oil, total microbes count (TMC) and operational costs were in the optimum region for drying peppermint either whole plants or leaves under the following recommended conditions: 1.Use the solar tunnel greenhouse for drying peppermint in order to keep its product quality with highest percent of volatile oil and lowest level of total microbes count. 2.Drying peppermint at air velocity 1 m/s where reduce drying time to (9and 8h) for whole plants and leaves, respectively. 3.Operate the solar tunnel greenhouse by continuously fan operating system which increased the drying rate by 22.78% and 24.8% for whole plants and leaves as comparison with periodical system. 4.Load the greenhouse by about 4 kg/m2. It is recommended for drying peppermint as leaves in order to contain the highest percent of volatile oil compared with the other morphological part of plant added to that reducing the drying time.