نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم و صنایع غذایی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان.
2 گروه گیاه پزشکی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان.
3 گروه شیمی، دانشگاه گلستان.
چکیده
پوشش خوراکی حاوی عصاره آویشن شیرازی (Zataria multiflora) به‌عنوان عامل جلوگیری‌کننده از فساد میکروبی و افزایش ماندگاری قارچ خوراکی دکمه‌ای (Agaricus bisporus) مورد مطالعه قرار گرفت. با استفاده از دستگاه GC Mass ترکیب‌های موجود در آویشن شیرازی شناسایی و مقدار تیمول به‌عنوان ترکیب ضدمیکروبی با استفاده از دستگاه HPLC اندازه‌گیری شد. همچنین شناسایی بار میکروبی در سطح کلاهک قارچ و اثر عصاره آویشن و تیمول با غلظت‌های 70و 105 میلی‌گرم بر لیتر در محیط کشت غذایی بر روی باکتری و کپک بررسی گردید. بدین منظور کلاهک رسیده قارچ دکمه‌ای با کربوکسی متیل‌سلولز 1 درصد به‌همراه عصاره آویشن شیرازی با سه غلظت 5/82، 125و 5/187 میلی‌گرم در لیتر پوشش داده و در دمای 8 درجه سلسیوس به‌مدت دو هفته نگه‌داری شدند و بار میکروبی در روز اول، هفتم و چهاردهم مورد بررسی گرفت. نتایج بدست آمده نشان داد، باکتری Psudomonas sp. و کپک Aspergillus sp. در مراحل مختلف نگه‌داری در سطح کلاهک نمونه شاهد رشد می‌کنند. همچنین درسطح محیط غذایی و کلاهک پوشش داده شده با افزایش غلظت آویشن و تیمول از تراکم باکتری و کپک کاسته شد. به‌طوریکه در غلظت 5/187 میلی‌گرم بر لیتر عصاره آویشن و 105 میلی‌گرم بر لیتر تیمول برای جلوگیری از رشد کپک و غلظت 125 میلی‌گرم بر لیتر عصاره آویشن و 70 میلی‌گرم بر لیتر تیمول برای جلوگیری از رشد باکتری مناسب می‌باشد.
کلیدواژه‌ها
عنوان مقاله [English]
Study of antimicrobial properties of Zataria multiflora extract and timol on durability and stability of edible mushroom (Agaricus bisporus)
نویسندگان [English]
- Minoo Rastegar 1
- Seyed Esmaeil Razavi 2
- Pouneh Ebrahimi 3
1 Center Laboratory, Gorgan University of Agricultural Science and Natural Resource, Gorgan, Iran.
2 Department of Plant Protection, Gorgan University of Agricultural Science and Natural Resource, Gorgan, Iran.
3 Department of Chemistry, Golestan University, Gorgan, Iran.
چکیده [English]
Introduction: White button mushroom (Agaricus bisporus) has a high moisture content (~90%) which makes it more vulnerable to the germs and chemical reactions. The contents of fungus coating are beneficial for shelf-life extension of mushroom. Coated mushrooms loss less moisture and have firmness, better appearance and color features than uncoated mushrooms (Zahedi et al., 1390). Application of food coatings is widely used in order to extend the shelf-life of foods including mushrooms. These methods include improved packaging methods, coated treatment with a solution of anti-microbial, plant extracts and anti-browning agents. The essential oil of thyme plant (Zataria multiflora) contains derivatives of phenol such as carvacrol and thymol (Aligiannis et. al, 2001). The interaction of essential components with each other plays an important role in determining antimicrobial effect. Therefore, the synergistic antimicrobial effects of thymol and carvacrol are enhanced (Didry et. al, 1994). It is worth noting that carvacrol through changes in permeability of H+/K+ ion channel in the cell membrane leads to the suppression of cell dysfunction and ultimately death (Ultee et al, 1999).
Materials and methods: Cap of button mushroom was coated by carboxymethyl cellulose, glycerol and thyme extract. In order to identify the thyme components, GC Mass model VARIAV CP3800 and VF5MS column was used. Also to measure the amount of thymol in thyme extract, HPLC method was used. The cap of button mushroom was sampled in three days (first day, seventh and fourteenth) and cultured in the food culture of PDA and NA.
Results and discussion: The results showed that the bacteria Psudomonas sp. and the mold Aspergillus sp. in various stages of maintenance of the control samples are observed in the warheads. The coating with thyme extract reduced the population of bacteria and mold. The results also showed that the medium level of microbial density was reduced with increasing concentrations of thyme extract. Therefore, the bacteria and mold did not grow in the extract concentration of 5.187 mgL-1. Thymol in a concentration of 70 and 105 ppm inhibited the growth of bacteria and mold, respectively. According to the results, 5.187 ppm thyme extract and 105 ppm thymol are suitable for coating and prevent the growth of bacteria and mold. The population of bacteria and mold in the treated and untreated samples of mushroom cap were identical. It was much more in the control sample with increasing storage time and was maximum at the end of the fourteenth day. The population of bacteria and mold in the coated samples and thyme extracts was lower than control samples. The direct relationship was observed with increasing storage time in the population growth of bacteria and mold. Lyzhyans et al. (2001) showed that the amount of phenolic oil is higher, the more antibacterial activity. The extract of thyme also contain phenolic compounds of thymol and carvacrol which have the most important role in creating antioxidant properties.
کلیدواژه‌ها [English]
- : Agaricus bisporus
- Zataria multiflora
- Timol
- Microbial contamination
- Shelf Life
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