M.A. Thesis:

The effect of coating by tragacanth Gum with manna and oregano essential oil on the organoleptic charactrestics and shelf life of pistachio kernel

Pistachio is one of the most important export items of the country. This is necessary to carry out numerous studies on the factors affecting quality and more durable pistachio recalls. In this study, in order to increase the durability of the kernel, the effect of edible coatings with different concentrations of the essential oil of oregano and the Manna Gum was investigated. The treatment after preparation packed in polyethylene bags were stored at ambient temperature for three months. Sampling was done each month and test chemical, biological and taste on all treatments carried out. The data in a completely randomized design and factorial test at 5% statistical level was analyzed and results of Duncan test was used to compare the averages. The results showed that with increasing concentration of oregano and manna, acidity and peroxide was reduced, but no significant effect on thiobarbitoric index. Results of analysis of variance mold and yeast count showed that the concentration of different treatments and manna Oregano essential oil as well as their interactions during storage, the statistical level of one percent, a significant effect on the growth of mold and yeast. So that the concentration of 500 ppm oregano and manna highest concentration of 2000 ppm rated the desirability of taste and flavor became the lowest rated utility.

Keywords: pistachio, edible coating, tragacanth, oregano, manna