Prevention and Control of Fungi Contaminated Stored Pistachio Nuts Imported to Saudi Arabia

To evaluate the contamination risk of the improper storage of pistachio nuts was studied in the major location of Saudi Arabia by studying the fungi associated with non and salted pistachio nuts. The infection with Aspergillus flavus and A. niger and treatment of this infection with some abiotic factors , salting and fumigation with acetic acid on the invasion and colonization were also studed. High percentage infection (100%) were found in salted pistachio of Maddinah , while low infection ( 68.75%) was found in non salted pistachio of Jeddah.Referring to the total fungal counts (9845.5 and 5681.8 CFU/g nuts) were detected on malt extract yeast agar and rose bengal agar media respectively. Aspergillus niger and A. flavus were found common in all pistachio samples collected from the three locations on the two media used. The both fungi were grew at temperatures between 20 and 35°C , also as the relative humidity increased the fungal growth increased reached its maximum at 100% RH. Sodium chloride at 20 and 25 % completely stopped the linear of the both fungi on malt yeast extract agar medium. Application of nuts with sodium chloride was found to increased the resistance of pistachio nut to invasion and colonization by the fungi during storage. Also, the resistance to invasion was increased by increasing the doses of fumigation with acetic acid applied to the pistachio nuts reached 0% infection at the higher dose of acetic acid (60%).