تولید فیلم های خوراکی بر پایه صمغ دانه اسفرزه غنی شده با اسانس لعل کوهستان

فیلم‌ها و پوشش‌های خوراکی لایه نازکی از پلیمرهای زیستی هستند که به عنوان پوشش مواد غذایی مورد استفاده قرار می گیرند. به دلیل معایب متعدد مواد بسته‌بندی سنتزی از قبیل مهاجرت ترکیبات بسته بندی به درون مواد غذایی، ایجاد آلودگی زیست محیطی و مشکل بازیافت پسماند اخیرا استفاده از فیلم های خوراکی جهت بسته‌بندی مواد غذایی افزایش قابل چشمگیری پیدا کرده است. فیلم های خوراکی بر پایه صمغ دانه اسفرزه به جهت دسترسی آسان و قیمت مقرون به صرفه منبع خوبی برای تهیه فیلم های خوراکی هستند. در این پژوهش فیلم های خوراکی بر پایه صمغ دانه اسفرزه غنی شده با نسبت‌های مختلف اسانس لعل کوهستان ساخته شد و ویژگی های فیزیکوشیمیایی فیلم‌ها شامل ضخامت، محتوای رطوبت، نفوذپذیری به بخارآب، مقاومت به کشش، درصد افزایش طول، ویژگی های مورفولوژی و حرارتی مورد بررسی قرار گرفت. نتایج آنالیز ترکیبات اسانس لعل کوهستان توسط gc/ms نشان داد که در مجموع 8 ترکیب شناسایی شد. نتایج نشان داد که با افزایش میزان اسانس لعل کوهستان ضخامت و درصد افزایش طول فیلم ها به طور معنی داری (05/0 > p) افزایش یافت، اما محتوی رطوبت، نفوذپذیری به بخارآب، مقاومت به کشش، دمای ذوب (tm) و دمای انتقال شیشه‌ای(tg) به طور معنی داری (05/0 > p) کاهش پیدا کردند. با توجه به نتایج کرنش تا نقطه شکست، با افزودن اسانس لعل کوهستان به فیلم ها، ویژگی انعطافپذیری در آنها افزایش یافت. همچنین ساختار همگن و یکنواخت فیلم کنترل (بدون اسانس) در تصاویر حاصل از میکروسکوپ الکترونی به قابل مشاهده بود.

production of edible films based on psyllium seed gum enriched with oliveria decumbens essential oil

introduction:synthetic plastics such as polypropylene, polyethylene and polystyrene are used as packaging materials in the food industry, which cause environmental pollution due to their non-degradability. in this way, solving this problem with biodegradable materials has been investigated. the increase in environmental problems caused by plastic packaging has led to the increasing use of food packaging. biopolymers extracted from food sources can be used as materials for biodegradable films. among these biopolymers, gum obtained from psyllium seed has the ability to form a good film and films based on gum obtained from psyllium seed have desired physical properties. one of the important properties of packaging is the protection of food against antimicrobial contamination, so in order to increase this property, nowadays packaging with antimicrobial properties is being investigated. one of them is the addition of various compounds with antimicrobial properties in food packaging, such as herbal essential oils. recently, the use of essential oils obtained from plants has received a lot of attention from food producers and consumers. an important use for them in food is flavoring, so essential oils play an important role in consumer satisfaction and affect the amount of food consumption. the preparation of edible film containing different essential oils has been studied by different researchers, but oliveria decumbens essential oil has not been studied in the formulation of the film obtained from psyllium seed gum. therefore, the purpose of this research is to add oliveria decumbens essential oil in the formulation of the film obtained from psyllium seed gum and to investigate the mechanical, physical and antimicrobial properties of the resulting edible film. material and methods: in this research, edible films were made based on psyllium seed gum enriched with different proportions of oliveria decumbens essential oil, and the physicochemical properties of the films included thickness, moisture content, permeability to water vapor, tensile strength, elongation percentage, morphological and thermal properties were investigated. all experiments were done in three replicates. statistical analyzes were performed in the form of completely randomized design using statistica version 13 software. average treatments were compared using duncan's method at the 99% confidence level. excel 2010 software was used to draw the figures. results and discussion: the results of the analysis of oliveria decumbens essential oil compounds by gc/ms identified a total of 8 compounds. the results showed that by increasing the amount of oliveria decumbens essential oil, the thickness and percentage of length of the films increased significantly (p < 0.05), but the moisture content, permeability to water vapor, tensile strength, melting temperature (tm) and the temperature of glass transition (tg) decreased significantly (p>0.05). the addition of oliveria decumbens essential oil in concentrations to the films based on psyllium seed gum significantly reduced the final tensile strength of the samples. in these films, the lowest and the highest ultimate tensile strength were related to the films containing 3% by volume of essential oil (14.28 mpa) and 1% by volume of essential oil (22.83 mpa). oliveria decumbens essential oil added to the films also showed the softening characteristic which was obtained from the results of strain to breaking point. the images obtained from the electron microscope showed that the control film (without essential oil) had a homogeneous and uniform structure. the melting peak of the control film appeared at the temperature of 81.8 ℃. this peak decreased to 80.3, 77.0 and 1.70 ℃ in films containing different proportions of oliveria decumbens essential oil (1%, 2% and 3%). this decrease in temperature can be due to the decrease in the hydroxyl groups of psyllium seed gum, which cause the creation of strong hydrogen bonds between polymer chains. conclusion: in this research, the possibility of producing edible films based on psyllium seed gum as a new hydrocolloid source was investigated and then the effect of adding different concentrations of oliveria decumbens essential oil on these films was investigated and finally the properties of the films was examined without essential oil and with essential oil. the results of the analysis of oliveria decumbens essential oil compounds by gc/ms identified a total of 8 compounds. the results showed that by adding essential oil to the films, thickness increases and moisture content, water vapor permeability, ultimate tensile strength, melting temperature and glass transition temperature decrease. more extensive research is needed to enable the use of these films in food packaging.