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Prevention and Control of Fungi Contaminated Stored
Pistachio Nuts Imported to Saudi Arabia
Lubna Saleh Nawar
Dept.of Biology, Fac. of Science, King Abd El-Aziz Univ., Jeddah, Saudi Arabia.
E-mail:lnawar@kau.edu.sa
Abstract
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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%).
Key words: Pistachio, Mould, Invasion, Cholonization, abiotic agents,
Salting, Fumigation.
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