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Dual properties of Enterococcus on the one hand, have made them suitable and accepted bacteria as starter cultures in the production of food products and probiotics, but on the other hand, because of antibiotic resistance properties and virulence factors, has resulted in concerns about the consumer’s health. In this study, in order to evaluate the antibiotic resistance of enterococcal isolates, the disk diffusion method was used. Also, culture-based method was applied for hemolytic and gelatinase activities. The results of the inhibition zone of Enterococcus isolates against common clinical antibiotics revealed that the isolates were sensitive to Vancomycin and Ampicillin and are resistant to Kanamycin and Streptomycin. The isolates showed very little resistance to Tetracycline and Chloramphenicol and none of the isolates were resistant to all tested antibiotics. Results obtained from hemolytic activity of isolates showed that none of examined isolates were capable of blood hemolysis and consequently no clear zone of inhibition in medium containing sheep’s blood. All of isolated were γ hemolytic and they have no hemolytic activity. Gelatinase activity results confirmed that none of the isolates are able to produce clear zone in tryptone soy agar containing gelatin.

 

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The consumption of extruded snacks has been increased among children. Due to their high content of fat and low nutritional value extruded snacks are contributing to a range of health problems which related to an unhealthy diet. Therefor they had an appropriate potential for production of functional foods. The objective of the research was to substitute fat used in the production of snacks coating partially by different levels of fat replacer containing native inulin (0-20%) and resistant starch (0-20%) in order to supply low fat flavoring of snacks. Based on mixture design the effect of fat replacers on rheological properties, color and emulsion stability of final products were investigated. Results showed that, addition of resistant starch increased emulsion stability of coating (1.42). The flow behavior index of samples were investigated by Power-law and Bingham model. Power-law was successfully fitted to the description of flow behavior of coating. Meanwhile, based on rheological properties,  all of the samples showed shear thinning behavior and the samples containing higher amount of inulin(20%) and lower amount of fat (80%) had the highest consistency coefficient (2.219 Pa.Sⁿ) and the lowest  and flow behavior index (0.868). The lightness of product was decreased by increasing fat replacers levels. The lowest amount of lightness belonged to sample containing inulin- resistant starch in 10-10% levels

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in this project, study of production of food by products (Spent coffee – wheat bran) in order to producing fiber solid foam using extrusion was carried out. Central composite design was used for evaluation of variables containing spent coffee: wheat bran ratio (75:25, 50:50, 25:75), feed moisture content (14, 17, and 20) and screw speed (120, 160, 200 RPM) on final moisture, water activity, expansion index, hardness and microstructure of extrudates. Results showed that by increasing spent coffee and moisture, water activity and humidity of solid foams were increased significantly. However screw speed had no effects on both properties. Improvement of spent coffee: wheat bran concentration in formulations in order to higher concentration of nonsalable fiber caused an increase in hardness and decrease in expansion index significantly. Increasing feed moisture content (14, 17, and 20) and screw speed simultaneously, showed an increase in expansion index and decrease in hardness. Microstructure Survey of solid foams illusterated that increasing spent coffee: wheat bran ratio leaded porosity reduction and improvement of cell wall size and reducing in air buble diameter. Based on optimization results, in order to production of solid foam with appropriate characteristics such as final moisture content (4.73%), wateractivity (0.29), expansion index (1.23), hardness (68.51 N), the process conditiond were determined at spent coffee: wheat bran ratio (69:31), feed moisture content (14.1) and screw speed (190 RPM)

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Snack foods contain main parts of food habit among people in the world. Recently the high rate of consumption and variety of extruded snacks is proven to increase the attention to nutritional quality besides keeping desired acceptability of products. In this study, based on central composite design the effect of independent variables consist of the whole Oleaster  powder (5- 15%), moisture content (12-20%), screw speed (120-180 RPM), were investigated on the physicochemical, textural and color of extrudates based on corn- wheat grit. results showed that, Increasing Oleaster content caused an increase in the density, hardness and solubility. Whereas, Increase screw rate and oleaster content simultaneously leaded to a lower density. In low amount of moisture content, improvement of oleaster content didn’t significant effect on hardness. However by boosting recent factors gradually, the hardness of products increased dramatically. Moisture content and screw speed had absolute effect on lightness of extrudates. Meanwhile improvement of oleaster content caused a decrease in lightness. Optimum condition was determined to be the feed moisture content (13.87%), oleaster content (5%) and screw speed rate (166.7 rpm).
 

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Abstract
In recent years, the individuals' demand for consumption of healthy and useful products has increased. With regard to the specific role of breakfast cereal in today's dietary habit, the incorporation of nutrients into their formulation is considered as a way to produce functional food products. So in this research, the effect of extrusion variables containing feed formulation (whole oleaster flour to whole oat flour (10 to 90, 25 to 75 and 40 to 60%), feed moisture (14, 18 and 22%) and screw speed (120, 150 and 180 rpm) on some properties of snack was investigated. Thus, the central composite design was used to assess the water absorption index (WAI), water activity (a_w), expansion ratio. Based on the obtained results, in a constant condition of other variables (feed moisture; 18% and screw speed; 150 rpm), an increase of the whole oleaster flour ratio from 10 to 40% decreased the WAI (from 5.64 to 5.16) and expansion ratio (from 1.72 to 1.48). While, an increase of the feed moisture from 14 to 18% led to an increase in the WAI (from 5.01 to 5.16) and water activity (from 0.33 to 0.63), when replacement level and screw speed were 25% and 150 rpm, respectively. The evaluation results of the screw speed in the moisture of 14 and 22% indicated that increasing the speed resulted in a decrease and increase in WAI, respectively. In addition, the relationship between the expansion ratio and microstructure was proved by scanning electron microscopy method. The optimum condition was found to the blends of whole oleaster flour/whole oat flour (10:90), screw rate of 180 rpm, and feed moisture content of 22% with desirable properties including (0.64%), expansion ratio(1.85), water absorption index(6.26).

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Extrusion cooking studies were carried out with a view to develop an instant ready to eat porridge from composite flour based on whole oat meal and broken rice. Full factorial design was carried out to investigate the influence of variables, feed moisture content (23, 27 %), cooking temperature (120, 145, 170 c°) and ratio of whole oat meal: broken rice 25:75, 50:50 and 75:25 % on physicochemical and functional properties contain, final humidity, water solubility index, color and porosity of extrudates. Results showed that increasing feed moisture content and whole oat meal simultaneously, showed an increase in humidity. Water solubility index (WSI) decreased with increase in feed moisture content, however with increase in level of whole oat meal, redness and WSI increased and porosity decreased. Increase in cooking temperature resulted in the decrease in lightness, humidity and increase in porosity of the extrudates. These findings suggest that fortified instant porridge have the potential to be adopted and can be used as a vehicle to deliver micronutrients to these populations and that extrusion with high yield, somewhat enhances the levels of soluble fiber fractions.

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Revival of native food, introducing it to the industrial cycle in accordance with the current modern lifestyle and the tendency to consume prepared foods, will play an effective role in maintaining the correct food pattern, increasing public health and offering it at the international level. Among them, cereal porridge (Harireh) containing almonds and rice flour is recommended as a traditional and beneficial food with high nutritional value for most age groups of the society. The production of this product is associated with limitations such as lack of quick preparation, non-uniform texture and short shelf life. Therefore, it is important to modify the formulation and process to introduce a super food to the market. In this research, extrusion technology was used to fabricate instant porridge from almond- oatmeal composite flour. For this purpose, the effect of humidity (12-16%) and the ratio of almond- oatmeal flour (10:90, 20:80 and 30:70) on the physicochemical and functional properties were evaluated using rotatable central composite design (CCD). The results showed, the simultaneous increase in moisture and the level of whole almond flour due to the increase in fiber and fat fraction caused an increase in density. At the level of 30% of almond powder, the antioxidant activity was at the maximum level. according to the optimization results; In order to have a product with the highest porosity, antioxidant capacity and water absorption along with the lowest density, the optimal treatment including feed moisture 13%, rotation speed 150 rpm and whole almond flour 22.3% was determined. This product, in addition to having suitable microstructure features, also has a favorable performance feature.
 

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In this research, extrusion technology was used to produce high-fiber snacks made from fresh cauliflower, corn starch, and corn flour. For this purpose, a central composite design and the response surface method (RSM) effects of various factors, including screw speed (120 to 180 rpm), cauliflower percentage (15%, 20%, 25%), and their impact on macrostructural, functional and color characteristics, such as expansion ratio, porosity, water solubility, water absorption index, and color changes of the snacks were investigated. The results demonstrated increasing the percentage of cauliflower increased the water absorption index (P<0.05) and whiteness index (P<0.0001) and also decreased the expansion ratio (P<0.0001) and porosity (P<0.0001) of the snack. It had no significant effect on the water solubility index. Increasing the screw speed led to an increase in the expansion ratio (P<0.0001), porosity (P<0.0001), solubility index in water(P<0.0001), and decreased whiteness index(P<0.0001) and water absorption index (P<0.05). The optimal sample was obtained by considering the maximum amount of cauliflower, the maximum water absorption index and the expansion ratio equivalent to the amount of cauliflower of 25% and the screw speed of 180 revolutions per minute with a desirability of 0.81 And after performing the test on the predicted values of the software, the non-significance of the average difference between the actual sample analysis results and the predicted sample values was observed, and The observations of the study indicate the promising potential of extruded snacks for enrichment purposes.