فهرست مطالب bahareh haji rostamloo

Extraction by the subcritical water method was studied as an efficient, economical, green, and environmentally friendly method to extract effective compounds of frankincense gum. For this purpose, subcritical water was used at temperatures of 120 and 160 ° C for 5 and 15 minutes. The amount of total phenolic compounds, radical scavenging ability, and antimicrobial properties of the extracts were investigated. The encapsulated powder of the extract obtained from the optimal conditions was also prepared by spray drying method and the particle size distribution and anti-aspergillus properties of that were also investigated. The results showed that the subcritical water extraction method significantly increased the extraction efficiency of frankincense gum extract. The amount of phenolic compounds extracted at 160 °C and time of 15 minutes was the highest among the extracts with 130.83 mg of gallic acid per 100g dry matter. The radical scavenging ability of the extracts from the subcritical water method was similar to that of the natural antioxidant ascorbic acid, and the extract from the maceration method as a traditional was less efficient at absorbing DPPH free radicals. Microbial results showed that the effects of extracts from maceration and subcritical water methods on Staphylococcus aureus were more than Escherichia coli. Encapsulated frankincense powder had no anti-aspergillus potency at concentrations less than 600,000 μg / ml.

The use of local products in the food industry has become increasingly important in recent years, and jujube fruit is one of the most important garden products in South Khorasan. The high potential of jujube fruit due to the presence of antioxidant and antimicrobial compounds can be used as an alternative to some of the industrial antioxidants in the field of edible oils. In the present study, the compounds in jujube fruit including meat and kernels were investigated. First, in order to extract jujube extract with better properties and efficiency, two types of aqueous and methanolic solvents were used. . Then jujube extract at three concentrations of 250, 500 and 1000 parts per million was compared with BHA industrial antioxidant. The results indicate the presence of phenolic compounds, alkaloids, saponins, sterols, tannins, terpenoids and steroids. On the other hand, it was observed that jujube extract had antimicrobial properties against Salmonella typhi, Bacillus subtilis, Listeria monocytogenes, Aspergillus nigero Candida albicans. Comparing the antioxidant properties of jujube extract with industrial antioxidant BHA, it was observed that jujube extract had less antioxidant activity and had lower peroxide, acid number, thiobarbituric acid index and DPPH (P> 0.05); But as an alternative, it can help prevent oil oxidation

Today, due to its environmental problems and importance, the use of biodegradable nanocomposite films is of particular importance. In this study, silver nanoparticles were synthesized by means of aqueous extract of Mentha and the adsorption capacity of 1,1-diphenyl- 2-picrylhydrazyl radicals and their antimicrobial activity should investigated by the method of determination of minimum inhibitory concentration. The uniformity and shape were structure of these nanoparticles was determined by scanning electron microscopy. The antimicrobial effect of starch-based nanocomposite films, together with these nanoparticles, was investigated by disk diffusion test and determination of minimum inhibitory concentration of nanoparticles by threeEscherichia coli, Staphylococcus aureus and Listeria monocytogenes. The results showed that silver nanoparticles showed the highest absorption at 430 nm and had a spherical shape and their average size was between 15-37 nm. The silver nanoparticles produced acted as DPPH radical inhibitors (IC50 = 170 μ M). The minimum growth inhibitory concentration and the minimum lethal concentration on Staphylococcus aureus showed 3.1 and 6.2 showed the highest minimum inhibitory concentration. Also, by measuring the diameter of the bright area by the disk penetration test, pure starch does not have antimicrobial properties, but by adding 250 ppm silver nanoparticles to the starch film in the presence of bacteria, a halo with a diameter of 2.55 cm is formed and in fact by adding nanoparticles antimicrobial properties Starch is formed in the film and again increases the diameter of the halo to 2.35 cm in the film by bringing the amount of silver nanoparticles to 500 ppm, which indicates an increase in antimicrobial properties. Starch- based biodegradable films with biosynthesized silver nanoparticles showed antimicrobial effect against all tested microbes (p <0.05).

Oxidation of lipids in food is one of the most important factors in food degradation during processing, storage and distribution through adverse effects on aroma, color, nutritional value and also the production of toxic compounds. In this regard, this study was conducted to investigate the antioxidant effects of free grape pomace extract and nanoliposomes containing it on some oxidation parameters of soybean oil. In this study, 5 concentrations of nanoliposomes containing grape pomace extract (50, 100, 200, 500 and 1000 ppm), one level (200 ppm) of synthetic antioxidant (BHT) and one concentration (500 ppm) of free grape pomace extract were used and tests such as Acidity, peroxide, thiobarbituric acid index, conjugate diene, oxidative stability and refractive index of oils were stored in a laboratory oven at 63 ° C for 7 days. The results showed that with increasing the concentration of nanoliposomes containing antioxidants of grape pomace extract up to 500 ppm, the increase in acidity, thiobarbituric acid index, peroxide, conjugated diene and refractive index was less intense, but at higher concentrations of nanoliposomes used in this oil, Increased more. On the other hand, it was found that with increasing storage time, the amount of acidity, thiobarbituric acid, conjugated diene increased, but the amount of peroxide and refractive index of oils increased until the fifth day and then decreased. The results also showed that the highest oxidative stability of oils (7.6 h) was related to the sample containing 500 ppm nanoliposomes containing antioxidant extract of grape pomace. Finally, it can be said that the use of nanoliposomes containing grape pomace antioxidant extract is a good alternative to synthetic antioxidants on the market.

In this investigation, to design the process of oil extraction from corn germ on an industrial scale, three cooking temperatures (80, 85 and 90 °C) and three different moisture contents of the output seeds from the cooking pot (3, 3.5 and 4%) were considered and the quantity of insoluble fine partial and oil acidity, oil, protein and moisture contents of the obtained meals were studied as responses. To predict the changes' trend the artificial neural network in MATLAB R2013a software was used. By studying the various networks of back propagation feed forward network with wide range of various topologies, the arrangement of 2-6-5 with a correlation coefficient (R 2 = 0.984) and the mean squared error (MSE=0.003) with using sigmoid hyperbolic of tangent activation function was selected as optimized design. Also Levenberg-Marquardt learning algorithm and learning cycle of 1000 were specified as the best neural model. The results of optimized selected models were evaluated and these models with high correlation coefficients (>0.953) were able to predict the variations process. On the other hand, the results showed that the models obtained in this study had the highest accuracy in predicting the moisture content of the meal. Finally, it was Experimentally determined that for the best properties of corn germ oil and meal, the cooker temperature and moisture contents of the output seeds from the cooking pot should be 80 ° C and 3%, respectively.

Some plants have antioxidant compounds and antimicrobial properties and can be used as fractional compositions in the industry. This study aimed to investigate the radical scavenging and antimicrobial properties as well as the determination of the compounds in the seed extract of Securigera securidaca. The plant seeds were extracted by maceration method using ultrasound (50 Hz) and dried extract in this study. Then, the compounds were identified by GC/MS device and the radical scavenging capacity was determined by DPPH. The antimicrobial properties of the extract were determined by disc-diffusion method against Escherichia coli, Listeria monocytogenes and Candida albicans strains. Fourteen (14) compounds were identified, containing 98.58% of total extract compositions, and the highest percentage was related to Mome Inositol (30.55%) and cis-9-Octadecenoic acid (20.44%). The highest radical scavenging capacity was observed at the concentration of 600 ppm of extract (91.6%). Different concentrations of the extract rather than the concentration of 0.25 mg/ml inhibited L. monocytogenes and all concentrations of extract had inhibitory effect on E. coli and the most effect was related to the concentration of 0.5 mg/ml (12.98 mm). None of the concentrations had an inhibitory effect on C. albicans. The results showed that the extract inhibitory effect increased on the strains effectively by increasing the concentration of extract. The plant extract can be used in the nutraceutical industries due to its appropriate antioxidant activity and antimicrobial properties.