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پژوهش حاضر به بررسی رابطه میان سواد رسانه‌ای و خوداثربخشی خلاق در کارکنان معاونت سیمای جمهوری اسلامی ایران پرداخته است. این پژوهش، توصیفی، از نوع همبستگی بودن و به روش پیمایشی انجام شده است. جامعه آماری، کارکنان معاونت سیمای جمهوری اسلامی ایران (2100 نفر) را شامل می‌شود که با روش تصادفی 324 نفر آنان به ‎عنوان نمونه انتخاب شده‌اند. برای جمع‌آوری داده‌های پژوهش از پرسشنامه محقق‌ساخته با اقتباس از پرسشنامه خلاقیت تورنس و پرسشنامه سواد رسانه‌ای فلسفی استفاده شده و روایی و پایایی در حد مطلوب و قابل قبول (با آلفای کرونباخ 88/0) به دست آمده است. یافته‌های پژوهش حاکی از آن است که بین سواد رسانه‌ای و خوداثربخشی خلاق در کارکنان سیمای جمهوری اسلامی ایران رابطه‌ای معنادار و مثبت وجود دارد؛ همچنین بین سواد رسانه‌ای و مؤلفه‌های خلاقیت از دیدگاه تورنس که در 4 مؤلفه؛ ابتکار، بسط خلاقیت، سیالیّت و انعطاف‌پذیری مورد بررسی قرار گرفته، رابطه معنادار و مثبت دیده می‌شود. نتایج این مطالعه نشان می‌دهد که چنانچه دانش و مهارت‌های سواد رسانه‌ای کارکنان رسانه ارتقا باید، توانمندی بالقوه آنان در بروز خلاقیت‌های شغلی بیشتر می‌شود و باور هر یک نسبت به توانایی خود در فکر، عمل و خلق راهکارهای خلاقانه افزایش می‌یابد. از آنجا که خوداثربخشی خلاق، پیش‌بینی‌کننده خوبی برای سطح عملکرد بالاتر شغلی افراد است؛ با اتکا به این دارایی نامشهود به‌عنوان اهرم و عاملی برای رقابت در تولیدات رسانه‌ای، می‌توان به خودشکوفایی کارکنان از یک‌سو و کاربست خلاقیت در تولید محتوای خلاقانه رسانه‌ای از سوی دیگر دست یافت.

Due to concerns about the safety and long-term health of synthetic antioxidants such as BHT and BHA, the use of natural compounds with antioxidant properties, such as bioactive peptides, has attracted the attention of many researchers. The aim of this study was to determine the optimum hydrolysis time of edible mushroom protein ( Agaricus bisporus) with alcalase enzyme to produce protein hydrolyzate with high antioxidant properties. For this study, first edible mushrooms were converted into powder and then was hydrolyzed in different times of 200, 150, 100, 50 and 250 minutes with an enzyme to substrate of 2% at temperature of 50 °C and then appropriate treatment based on antioxidant properties of the produced sample was determined. The results showed that hydrolysis time 200 minutes is suitable to achieve maximum antioxidant properties. Next, the effect of different concentrations (10 to 50 mg/ml) of hydrolyzed protein prepared under optimal conditions on the antioxidant properties of the product compared to ascorbic acid (50 mg/ml) was investigated. In all the tests, the product showed a concentration-dependent behavior and with increasing concentration, the DPPH free radical scavenging, iron ion reduction power and total antioxidant power increased and in concentrations of 40 and 50 mg/ml the antioxidant power was similar to ascorbic acid (50 mg/ml). The results showed that the hydrolyzed protein produced has the potential to be used as a functional ingredient and as an alternative to synthetic antioxidants in food formulations. [ABSTRACT FROM AUTHOR]

In recent years, researchers have identified and extracted bioactive peptides with acceptable antioxidant properties from animal and vegetable protein sources. According to research, "Flaxseed meal" which is the main by -product of the linseed oil extraction process; It contains a large amount of protein, which can be obtained by enzymatic hydrolysis to peptides with antioxidant properties. In this research, the effect of hydrolysis conditions (enzyme concentration 2.7 -1% and time 30 -183.64 minutes), type of protease (pancreatin and alcalase) and ultrasound pretreatment on the degree of hydrolysis and antioxidant properties (DPPH free radical inhibition, Total antioxidant activity and iron ion chelation) of hydrolyzed protein obtained from flaxseed meal were evaluated using the response surface method. The results showed that the optimal conditions for the production of hydrolyzed protein with the most antioxidant properties with alcalase enzyme with and without pretreatment and pancreatin enzyme with and without pretreatment respectively were: hydrolysis time 79, 146/79, 111.77 and 97.21 minutes and enzyme concentration 2.29%, 1.46%, 2.26% and 1.38%; According to the obtained results, by examining the degree of hydrolysis and antioxidant properties of the hydrolyzed proteins of flaxseed meal, hydrolyzed protein with pancreatin enzyme was suggested as the optimal treatment. Hydrolyzed protein with pancreatin enzyme with ultrasound pretreatment was reported to have 75.66% DPPH free radical inhibition, 70.39% iron ion chelating activity, total antioxidant activity with absorbance of 0.86 nm and 80.69% hydrolysis degree. Therefore, it can be stated that the hydrolyzed protein of flax seed meal with strong antioxidant capacity is a bioactive compound for use in food formulations and the production of beneficial products. [ABSTRACT FROM AUTHOR]

In fish processing industries, 50-70% of primary fish are produced as waste, while they are rich sources of protein and essential amino acids. The optimal use of these wastes and the production of compounds with high added value that have significant health-giving properties is one of the important challenges of fish processing industries. In this research, the effect of hydrolysis conditions (time: 30-300 minutes and enzyme concentration 0.5-3%) and type of protease (pepsin and trypsin) on the degree of hydrolysis and antioxidant properties (DPPH radical scavenging activity, Fe chelating activity, No radical scavenging activity, total antioxidant capacity and Fe reducing power) of hydrolyzed protein obtained from Skipjack viscera were evaluated using response surface methodology. The results showed that the optimal conditions for the production of hydrolyzed protein with the maximum antioxidant properties with pepsin and trypsin enzymes were respectively: hydrolysis time of 179.09 and 143.62 minutes and enzyme concentration of 2.63 and 1.94 %; In this condition, the degree of hydrolysis of the hydrolyzed proteins resulting from the activity of trypsin was calculated to be higher than that of pepsin. Comparing the antioxidant properties of the hydrolysates obtained from the two enzymes used showed that the hydrolyzed protein obtained from trypsin had a stronger antioxidant potential than pepsin. Therefore, it can be stated that the hydrolyzed protein of the Skipjack viscera using trypsin enzyme as a health-giving supplement and with high added value can be used in the production of functional food products and health supplements for athletes and elderly people. [ABSTRACT FROM AUTHOR]

Background and purpose: The formation of free radicals in aerobic organs is inevitable. These radicals cause cells and tissues damages. Oxidation of lipids by producing harmful compounds and as theresult spoilage of food products is one of the most important concerns of the food industry. The use of synthetic antioxidants is tightly controlled due to their harmful effects on human health. Therefore, scientists' research has turned to the identification and extraction of natural antioxidant compounds. Bioactive peptides are specific protein components that are inactive at the primary protein source and are produced by enzymatic hydrolysis, microbial fermentation, and chemical synthesis. These peptides have different health-promoting properties such as antihypertensive, anticholesterol, anti-cancer, strengthening the immune system and antioxidant properties that are influenced by their amino acid composition and sequence. This study aimed to investigate the effect of molecular weight and amino acid composition on the antioxidant properties (DPPH radical scavenging activity, Fe reducing power and ABTS radical scavenging activity) of peptide components of pumpkin seed protein hydrolysate. Materials and Methods: Pumpkin seed protein hydrolysate was prepared under optimum conditions based on the results of previous research and then the effect of molecular weight distribution on the bioactive properties of the resulting fractions and also the relationship between the amino acid composition of these peptides and their antioxidant properties after separation and purification by size exclusion chromatography (SEC) and reverse phase high pressure liquid chromatography (RP-HPLC) was examined. Results: The results of size exclusion chromatography showed that fractions 49 to 56 and 49 to 63 with a molecular weight in the range of 9000 to 13,000 daltons have the highest DPPH and ABTA radical scavenging activity. The antioxidant activity reached its maximum value after further purification of fractions with a holding time of 22 minutes by RP-HPC. The results of the amino acid analysis showed that fractions with high antioxidant capacity contain high amounts of hydrophobic amino acids (about 33.5%), which include non-polar aliphatic groups (such as valine, isoleucine, proline, leucine, tryptophan, and tyrosine). In other words, low molecular weight peptides, with aromatic and hydrophobic amino acids have higher antioxidant activity. Conclusion: Pumpkin seed protein hydrolysate with peptide components of significant antioxidant properties, can compete with synthetic antioxidants used in the food industry. Therefore, it can be used as a natural preservative in food formulations to produce functional products to increase public health levels and for medicinal purposes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the influence of Arabic gum concentration on production yield, physicochemical and morphological properties of spray dried stevia extract. Also, the effect of stevia powders replacement with sucrose on physicochemical, textural and sensory properties of Aloe Vera jelly was investigated. The spray drying process using Arabic gum was carried out at concentrations of 10, 20 and 30% (w/v). Then, 25, 50 and 75% of sucrose in the formulation of Aloe Vera jelly was replaced with 0.25, 0.50 and 0.75% of stevia powders. The results revealed that the maximum yield of powder (47.73%) has been obtained at 10:90 Arabic gum to extract ratio. The amount of moisture, water activity and hygroscopicity of powders decreased with increasing the carrier ratio. Other properties such as bulk density, particle density and true density, solubility and wettability of powders also decreased with increasing the carrier ratio. These properties were varied in the range of 0.39-0.46 g / ml, 0.42-0.57 g / ml, 1.42- 1.55g / ml, 89.10-92.30%, and 15.39- 27.52 s. Also, flow ability behavior of samples improved by increasing the carrier ratios. According to the results of scanning electron microscopy, the increasing of carrier concentration also led to the production of larger particles with wrinkled surface and irregular shapes. Evaluation of the physicochemical properties of the jelly samples revealed that by increasing the stevia concentration, the moisture content, syneresis and acidity of samples increased, while the brix, gel strength and pH decreased. Treatments containing 0.25% and 0.50% of 10% Stevia powder and treatment containing 0.25% of 20% Stevia Powder, showed higher acceptability regarding sensory characteristics and did not show significant differences with the control sample. [ABSTRACT FROM AUTHOR]

Fenugreek seed protein (Graceum Trigonella foenum) is a rich source of lysine and tryptophan. In this study, the enzymatic hydrolysis of fenugreek seed protein with the pancreatin enzyme was performed using the response surface methodology with independent variable including: temperature 20 - 60 ° C, time 30-270 min, and enzyme to substrate ratio of 0.25-3/25%. Optimum conditions to achieve the highest 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity and reducing power were obtained at 46/12 °C, and enzyme to substrate ratio of 1.84% and time of 175.96 min. Then, the antioxidant properties of the optimum treatment were measured at different concentrations (10-50 mg/ml) and compared with antioxidant properties of non-hydrolyzed protein and vitamin C. The highest DPPH radical scavenging activity (52.98%), and total antioxidant activity (absorbance 1.28 at wavelength of 695 nm) were achieved at concentration (40 mg/ml), and the highest hydroxyl radical scavenging activity (70.99%) and Fe2+ chelating activity (72.63%) and Fe reducing power (0.80 at wavelength of 700 nm) were achieved at concentration (50 mg/ml). According to the results, the hydrolysis of fenugreek protein by the pancreatin enzyme had led to the production of peptides with significant antioxidant activity that can compete with synthetic antioxidants. Also, these peptides can be used in the pharmaceutical industry and the production of functional foods. [ABSTRACT FROM AUTHOR]