فهرست مقالات لیلا منجزب مرو دشتی


  • مقاله

    1 - تولید زیست پلیمر کردلان توسط Agrobacterium radiobacter در محیط کشت حاوی ضایعات انگور
    میکروب شناسی مواد غذائی , شماره 4 , سال 5 , پاییز 1397
    کردلان پلی ساکاریدی نامحلول در آب و گران‌قیمت است که از واحدهای 14β"> (1‌3)D-گلوکان تشکیل‌شده است. خواص ژل ایجادشده توسط گرما باعث شده کردلان در صنایع غذایی از اهمیت بالایی برخوردار شود. یکی از اصلی‌ترین فاکتورهای محدودکننده استفاده گسترده از کردلان، هزین چکیده کامل
    کردلان پلی ساکاریدی نامحلول در آب و گران‌قیمت است که از واحدهای 14β"> (1‌3)D-گلوکان تشکیل‌شده است. خواص ژل ایجادشده توسط گرما باعث شده کردلان در صنایع غذایی از اهمیت بالایی برخوردار شود. یکی از اصلی‌ترین فاکتورهای محدودکننده استفاده گسترده از کردلان، هزینه تولید بالای آن است. لذا به‌کارگیری ضایعات کشاورزی راهی مناسب برای این مشکل است. در این تحقیق، تولید کردلان توسط باکتریAgrobacterium radiobacterPTCC 1654 در محیط کشت با غلظت‌های مختلف (5، 5/7 و 10 درصد) شیره انگور و ساکارز به عنوان منبع کربن، مورد ارزیابی قرار گرفت. علاوه بر این، میزان کردلان و بیومس تولیدی تعیین و ترکیب قندهای پلی ساکارید به‌دست‌آمده با استفاده از تکنیک کروماتوگرافی لایه‌نازک تعیین شد. تغییرات pH محیط تخمیر نیز در طول فرایند مورد ارزیابی قرار گرفت. نتایج نشان داد بالاترین میزان تولید پلی ساکارید، در محیط تخمیر حاوی شیره انگور با بریکس 5/7 و پس از گذشت 144 ساعت از شروع تخمیر به دست آمد. pH محیط تخمیر در طول فرایند تخمیر از 7 به حدود 5/5 کاهش یافت. نتایج کروماتوگرافی لایه نازک پلی ساکارید تولیدی نشان داد که تنها مونومر تشکیل‌دهنده ساختار این پلیمر، گلوکز بود. نتایج همچنین نشان داد که شیره انگور در مقایسه با ساکارز خالص به شکل معنی‌داری بازدهی بالاتری در تولید کردلان داشت (05/0p<). بنابراین در این زمینه دارای مزیت نسبی بود. بر اساس یافته‌های حاصل از پژوهش حاضر می‌توان نتیجه گرفت، ضایعات کشاورزی نظیر شیره انگور را می‌توان به‌عنوان منبع کربن فرایند تخمیر برای تولید پلیمر کردلان استفاده کرد. پرونده مقاله

  • مقاله

    2 - Active Packaging Film Based on Lysozyme/Polyvinyl Alcohol / Alyssum Homalocarpum Seeds Gum
    Journal of Chemical Health Risks , شماره 5 , سال 10 , پاییز 2020
    The active films composed of polyvinyl alcohol/Alyssum homolocarpum seeds gum (PVA-AHSG) in corporatinglysozyme (LY) are developed and characterized. The LY affects the thickness, solubility, and water vapor permeability, mechanical, microstructural, and optical propert چکیده کامل
    The active films composed of polyvinyl alcohol/Alyssum homolocarpum seeds gum (PVA-AHSG) in corporatinglysozyme (LY) are developed and characterized. The LY affects the thickness, solubility, and water vapor permeability, mechanical, microstructural, and optical properties of PVA-AHSG films and also the antimicrobial activities of obtained films are evaluated. The LY content increased the thickness of composite films. The LY addition led to an increase in water solubility, moisture contents, and contact angle, and decreased density. The control films without LY had the lower opacity and acted as a weak barrier against the water vapor. The LY reduced elongation at break and slightly increased tensile strength and elastic modulus. The electron micrographs showed that the control films had a smoother structure, and the addition of LY formed films with a rough surface. Fourier Transform-Infrared Spectra indicated some interactions between PVA and AHSG chains and LY. Functional activities were found against Gram-positive Listeria monocytogenes and Staphylococcus aureus. پرونده مقاله

  • مقاله

    3 - Determination of Magnesium, Calcium and Sulphate Ion Impurities in Commercial Edible Salt
    Journal of Chemical Health Risks , شماره 2 , سال 10 , بهار 2020
    Natural elemental impurities are recognized as a threat for safety and quality of edible salt and have adverse effects on public health. In the current study, fiftysamples of packages containing 1 kg of salt from 25 different brands were collected from retailers in Semn چکیده کامل
    Natural elemental impurities are recognized as a threat for safety and quality of edible salt and have adverse effects on public health. In the current study, fiftysamples of packages containing 1 kg of salt from 25 different brands were collected from retailers in Semnan city (Iran). The concentrations of main impurities of edible salt including magnesium (Mg), calcium (Ca), and sulphate (SO4-2) ions were quantified by the aid of an Ion Chromatography with conductivity detector. According to findings, the maximum concentrations of Mg, Ca, and SO4-2 ions in salt samples were 0.067, 0.226, and 0.888 % w/w (dry matter basis), respectively. In addition, the concentration of Mg in 16%, Ca in 4%, and SO4-2 in 28% of samples suppressed the acceptable limit proposed by the Institute of Standards and Industrial Research of Iran (ISIRI) (0.15% for Ca, 0.03% for Mg, and 0.46% for SO4-2). Moreover, the maximum and minimum levels of purity in the salt samples were recorded as 99.940 and 97.730%, respectively. Moreover, the purity in 12% of the investigated samples was lower than that of the minimum acceptable limit suggested by ISIRI, while the purity of 97% samples met the acceptable Codex Alimentarius limit (97% Min). Based on results of the current investigation, the routine purification processes used in some factories of Iran did not reduce impurities. Hence, purification process bedsides constant monitoring and safety management should be improved to promote the health quality of edible salt. پرونده مقاله

  • مقاله

    4 - Edible Film Based on Lallemantia peltata L. Seed Gum: Development and Characterization
    Journal of Chemical Health Risks , شماره 1 , سال 12 , زمستان 2022
    A novel edible film was developed using Lallemantia peltata (L.) seed gum (LSG), and its water sensitivity, physico-mechanical, barriers, microstructural and thermal properties as a function of glycerol concentration (20, 30, 40, 50 and 60% w/w) were studied. Different چکیده کامل
    A novel edible film was developed using Lallemantia peltata (L.) seed gum (LSG), and its water sensitivity, physico-mechanical, barriers, microstructural and thermal properties as a function of glycerol concentration (20, 30, 40, 50 and 60% w/w) were studied. Different models were also used to investigate the water sorption of the LSG films. Unplasticized LSG films were brittle and difficult to handle which were effectively modified by glycerol addition. Water sensitivity, oxygen permeability, and elongation of LSG films were increased with increasing glycerol concentration. Also, increasing of glycerol concentration resulted in reduction of tensile strength, glass transition temperature (Tg) and melting temperature (Tm) of the films. Electron scanning micrographs revealed a smooth surfaceand compact cross-section microstructure in LSG films.The films showed sigmoid shape type II water sorption isotherms, representing typical features of most of biopolymers. Accordingly, the results suggest that LSG films containing desired glycerol concentration could potentially be used as edible films in food packaging. پرونده مقاله

  • مقاله

    5 - Iodized Salt: Assessment of Nutritional Status, Iodine Intake and Iodine Exposure
    Journal of Chemical Health Risks , شماره 4 , سال 11 , تابستان 2021
    Food grade salt is the main carrier for iodine fortification to prevent iodine-deficiency disorders in iodine-deficient regions. Excessive and also too low iodine content in salt could cause diseases and human health risks. This study is aimed to investigate the iodine چکیده کامل
    Food grade salt is the main carrier for iodine fortification to prevent iodine-deficiency disorders in iodine-deficient regions. Excessive and also too low iodine content in salt could cause diseases and human health risks. This study is aimed to investigate the iodine content of edible salts produced in Semnan province (Iran) and also the iodine intake and exposure were estimated in population. Iodine content of 75 salt samples from 25 different brands produced in Semnan province were measured using titration method. Urinary iodine was determined in 240 children (8-12 years old). Iodine intake and exposure was determined based on the defined variables. The results indicated that the mean iodine concentration of 32% iodized salt samples were not according to acceptable range (30-50 mg.kg-1(set by Iranian National Standard Institute. The urinary iodine median was 161 µg.L-1 and in 7.5% of studied population was more than 300 µg.L-1. The mean of daily iodine intake in all samples was 298.4 ± 79.6 µg per day. Obtained iodine exposure values demonstrated that the status of iodine intake in Semnan province was at optimal nutrition and no risk of iodine deficiency treat the population. پرونده مقاله

  • مقاله

    6 - Smirnovia Iranica Whole Herb Extract: Antioxidant, Radical Scavenging, Anti-microbial and Anti-Cancer Effects
    Journal of Chemical Health Risks , شماره 2 , سال 13 , بهار 2023
    In this study, the biological activities of whole herb extract of a medicinal plant named Smirnovia Iranica were investigated. The extraction was performed using Supercritical CO2 and phytochemical compounds, total phenolic content (TPC), total flavonoid content (TFC), چکیده کامل
    In this study, the biological activities of whole herb extract of a medicinal plant named Smirnovia Iranica were investigated. The extraction was performed using Supercritical CO2 and phytochemical compounds, total phenolic content (TPC), total flavonoid content (TFC), antioxidant, anti-bacterial, and anti-cancer effect were determined in the extract. Based on the results, high TPC concentration (120.36 mg GAE/100 g FW) and TFC (17.41 mg quercetin/100g FW) were obtained in the extract. Besides, the extract showed significant antioxidant activity (IC50=53.97 µg mL-1). Moreover, the extract showed a notable inhibitory effect againstEscherichia coli(MIC=15.63 mg mL-1) andSalmonella enterica (MIC=31.25 mg mL-1). On the other hand, this extract showed the cytotoxic effect on glioblastoma cancer cell lines in the MTT assay. This is the first, yet comprehensive, scientific report about the chemical composition and pharmacological properties of the extract of Smirnovia Iranica whole herb. According to current results, the Smirnovia Iranica extract has excellent antioxidant properties for application as bioactive components for various objects such as as food supplements. The experiment confirmed the efficacy of the extracts as natural antimicrobials and suggested the possibility of employing them in drugs for the treatment of infectious diseases caused by the test organisms. پرونده مقاله

  • مقاله

    7 - Elaeagnus angustifolia L. Whole Fruit Ethanolic Extract: Phytochemical Composition and Antimicrobial Effects
    Journal of Chemical Health Risks , شماره 1 , سال 14 , زمستان 2024
    In this research chemical composition and antimicrobial effects of Elaeagnus angustifolia L. (E. angustifolia L.) whole fruit ethanolic extract was investigated on common pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Cand چکیده کامل
    In this research chemical composition and antimicrobial effects of Elaeagnus angustifolia L. (E. angustifolia L.) whole fruit ethanolic extract was investigated on common pathogenic microorganisms (Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Candida albicans). The phytochemical composition of E. angustifolia was screened by Gas Chromatography-Mass Spectrometry (GC/MS). The minimum inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of the extract were determined using the broth dilution technique. According to the results, 13 major compounds such as flavonoid, aldehyde, alcoholic and fatty acids were identified by GC/MS. In addition, the extract could inhibit the growth of all examined pathogenic strains. The MIC was 3.75 to 1.87 mg ml-1 while maximum activity was found against Staphylococcus aureus. Besides, the MBC was ranging from 7.5 to 3.75 mg ml-1. Since E. angustifolia whole fruit ethanolic extract contains phytochemical compounds and has antimicrobial potential it can be recommended as a natural active agent for application in the food industry. پرونده مقاله

  • مقاله

    8 - Enhancing Shelf-life and Quality of Ready-to-Eat Pomegranate Arils with Nanocomposite Film: A PLA/ZnO nanoparticle/Zataria multiflora Essential Oil Innovation
    Journal of Chemical Health Risks , مقالات زودآیند
    The dried pomegranate (Punica granatum L.) arils have several health benefits and are in demand worldwide. Beside this they are highly perishable due to their high water content and susceptibility to microbial growth, resulting in shortened shelf-life and compromised qu چکیده کامل
    The dried pomegranate (Punica granatum L.) arils have several health benefits and are in demand worldwide. Beside this they are highly perishable due to their high water content and susceptibility to microbial growth, resulting in shortened shelf-life and compromised quality attributes. Therefore, in the current study, the wrapping effects of Poly L-lactide (PLA) activated with zinc oxide nanoparticles (ZnO NPs, 1.5% w/w) and Zataria multiflora Boiss. essential oil (ZEO, 1 and 1.5% w/w) were studied on pomegranate arils' storage-life extension in cold storage. The arils were periodically analyzed for physiochemical properties (weight loss, pH, total soluble solids, color measurement, antioxidant activity, and sensory attributes) and microbial properties (total aerobic bacteria and total fungi counts). Results showed that ZEO caused a decrease in pH during storage, while ZnO caused an increase. The active films were more effective than the control film in maintaining TTS and preventing weight loss of the arils. The PLA/ZnO/1.5% ZEO sample had the highest phenolic content (∼520 mg 100 ml-1 in juice) and antioxidant activity (∼90%) on day 15. However, ZEO had a greater effect on the color properties of the arils compared to ZnO, with 0.5% and 1.5% ZEO-PLA showing the highest a* (55.14) and b* (31.30) values with fresh arils, respectively. The microbial test results showed that ZEO was more effective in controlling bacterial growth than ZnO. Based on atomic absorption spectrophotometer measurement, minimal amounts (∼29 mg Kg-1 sample) of Zn2+ ions were observed to be released into the arils. Overall, the active PLA could be used as a safe and effective way to prolong the storage life of arils in refrigerated conditions. پرونده مقاله