en Toxicology and polution Toxicology and polution پژوهشي Original research papers <div style="text-align: justify;">Foodborne diseases in nature are usually infectious or toxic, caused by bacteria, viruses, parasites or chemicals, transmitted through food or water contaminated by the human body. To control the disease, as well as to ensure that the food is safe and healthy, its risks must be checked, detected and controlled. The goals of food industry are to produce healthy and high quality products that requires no contamination with bacteria. The use of natural preservatives such as herbal extracts and essential oils is recommended. <em>Allium atroviolaceum</em> is a family of Alliaceae and is a perennial herb which has a high nutritional value. The role of plant extracts has been evaluated as a preservative.&nbsp;The total number of bacteria calculated followed by treatment of the aqueous and ethanol extractions of the <em>A. atroviolaceum </em>on rainbow trout fish fillet. 100 &micro;l of aqueous and alcoholic extracts followed by ten times dilution used to evaluate the minimum inhibitory concentration, then 25 grams of rainbow trout fillet was submerged with the best concentrations of aqueous and alcoholic extracts.&nbsp; The results illustrated that the best aqueous and alcoholic extractions against <em>Staphylococcus aureus</em> was 3.125 mg ml^-1 and 6.25 mg ml^-1 and followed by treatment on fish both type of extraction showed inhibition on growth of bacteria compare to control group. So we believe that this plant has such a valuable effect to improve the quality and shelf life of fish.</div> <br> &nbsp; Allium atroviolaceum, Total count of bacteria, Aqueous extraction, Ethanol extraction 86 94 http://ijaah.ir/browse.php?a_code=A-10-235-2&slc_lang=en&sid=1 B Hafeznia behzad.hafez@yahoo.com 10031947532846002140 10031947532846002140 Yes Department of Agricultural Sciences and Food Industries, Science and Research Branch, Islamic Azad University, Tehran, Iran S. A. A Anvar saaa4824@gmail.com 10031947532846002141 10031947532846002141 No Department of Food Hygiene, Science and Research Branch, Islamic Azad University, Tehran, Iran S Kakoolaki bsh443@gmail.com 10031947532846002142 10031947532846002142 No Department of Agricultural Research Education and Extension Organization, Iranian Fisheries Science Research, Institute, Tehran Iran N Choobkar Nchoobkar20@gmail.com 10031947532846002143 10031947532846002143 No Department of fisheries, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran