M.A. Thesis:

The study of combined processes of edible coating ٫ Ultrasound and osmotic dehydration on quality parameters and shelf life extension of pineapple

Traditional method of drying has several disadvantages, including the production of high microbial load, the use of sulfur compounds, unsatisfactory shape and color, lack of transparency and high shrinkage .While osmosis process is a suitable method that despite the lack of sulfur compounds usage , the resulting product has better flavor and color. In this experiment, fresh pineapples were washed and peeled ,then ,before osmotic dehydration , gum basil seeds with 1%, 2%, and sekanjabin syrup was used as osmotic environment for covering the production. Sekanjabin density was 40%, 50,60% . After the coating of parts, and coverage stabilized, at an intervals of 0, and 30 minutes they were under the sonication process (khz25) . Then the dehydration process without sonication, was continued . osmotic solution immersion time was 180 minutes. The results showed with increasing concentrations of dissolved solids in water, loss and absorption increases. Using Basil seed gum coating causes improvement the efficiency of osmotic dehydration, increasing water loss and reducing the absorption of dissolved solids in the drying osmotic pineapple and also by using ultrasound wrinkles in the fruit will be reduced significantly and increased PH and rehydration .Sensory assessment of the color, flavor, texture and overall acceptability between the coated and uncoated samples showed that uncoated samples are more acceptable than the coated and control samples. Keywords: pineapple, osmotic, chemical characterization, ultrasonic

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