35 research outputs found

    Twin-screw Extrusion Processing of Rainbow trout (Oncorhynchus mykiss) feeds using Graded Levels of High Protein Corn-based Distillers Dried Grains (HP-DDG) and Conventional Distillers Dried Grains with Solubles (DDGS)

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    Twin-screw extrusion cooking trials were performed to investigate the differential effects of conventional DDGS (DDGS) and HP-DDG inclusion, as fishmeal replacers, on physical properties (moisture content, water activity, thermal properties, expansion ratio, unit density, bulk density, water absorption, solubility and pellet durability indices, and color) of Rainbow trout (Oncorhynchus mykiss) feed. Four ingredient blends were formulated with 20 and 40% C- DDGS, and 20 and 40% HP-DDG, along with other required dietary ingredients. Each diet was extruded using two replications; a fishmeal based diet acted as the control diet. The highest and the lowest extrudate moisture content and water activity were observed for the diets containing 20% DDGS and 40% HP-DDG, respectively. Compared to the control diet, increasing HP-DDG content from 20 to 40% had no effect on the bulk density of the products, while increasing DDGS content from 20-40% led to a considerable rise in bulk density of the extrudates by 14.2 and 6%, respectively. Also, extrudates with the lowest brightness, greenness, and yellowness values were obtained from the diet containing 20% DDGS, whereas the most color intensity values were observed for the diets containing 40% DDGS and 20% HP-DDG. Increasing DDGS and HP-DDG from 0-40% caused a remarkable increase in water absorption index, by 72 and 30%, respectively. Likewise, the water solubility index increased, but in a considerably lesser order of magnitude. High pellet durability index of more than 99% was achieved with inclusion of either DDGS or HP-DDG. None of the diets impacted the thermal properties of the extrudates. Inclusion of 20 and 40% DDGS resulted in the extrudates with the largest and the smallest unit density values of nearly 887 and 750 kg/m3, respectively. As was expected, expansion ratio decreased with increasing unit density. Increasing inclusion levels of HP-DDG did not show any effect on unit density or expansion ratio of the products. Future research should concentrate on investigating the effects of both extrusion processing and graded levels of different types of DDGS on Rainbow trout feeds

    Twin-screw Extrusion Processing of Vegetable-Based Rainbow trout (Oncorhynchus mykiss) Feeds Using Graded Levels of High Protein Fermented Soybean Meal (FSBM)

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    Fast-paced growth in global aquaculture has elevated concerns about the high costs of aquafarm production and potential water pollution. Thus, finding eco-friendly and more sustainable alternative protein sources for fish diets is of vital importance to the industry. A twin-screw extrusion processing study was performed using three ingredient blends formulated with graded levels of FSBM (0, 80% and 100% db) as the fishmeal replacer, in combination with appropriate amounts of other required ingredients for rainbow trout diets. Increasing the FSBM content from 0% to 100% resulted in a substantial increase in brightness, greenness, and yellowness, and a decrease in bulk density, water absorption index, and unit density (UD) values of the extrudates by 12.5%, 73%, 30%, 7.3%, 27.5%, and 10%, respectively. Compared to the control diet (100% fishmeal-based), extrudate moisture contents increased by 15.2% and 22% for the diets containing 80 and 100% FSBM, respectively; although no change was observed by increasing FSBM from 80 to 100%. The highest water solubility index (WSI) was obtained for 80% FSBM; however, further increasing FSBM did not influence the WSI significantly. All extrudates exhibited low water activity and high pellet durability values (less than 0.5 and more than 99.5%, respectively). The most buoyant extrudates were obtained using total FSBM inclusion, with UD and expansion ratio values of nearly 660 kg/m3 and 1.3, respectively. Overall, results indicated that FSBM can be a promising alternative protein in rainbow trout feed production

    Twin-screw Extrusion Processing of Vegetable-Based Protein Feeds for Yellow Perch ( Perca flavescens) Containing Distillers Dried Grains (DDG), Soy Protein Concentrate (SPC), and Fermented High Protein Soybean Meal (FSBM)

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    Changing to alternative protein sources supports production of more economic aquafeeds. Two isocaloric (3.06 kcal/g) and isonitrogenous (40% db) experimental feeds for juvenile yellow perch were formulated with incorporation of FSBM and SPC, each of which were at two levels (0 and 20% db), along with constant amounts of high protein DDG (~30% db), and appropriate amounts of other ingredients. Using a pilot scale twin-screw extruder, feed production was performed in two replications for each diet at conditioner steam levels of 0.11 to 0.16 kg/min, extruder water of 0.11 to 0.19 kg/min, and screw speeds of 230 to 300 rpm. The effects of SPC and FSBM inclusions on extrudate physical properties were compared with those of a control diet (which contained 20% fishmeal and ~30% DDG). Inclusion of 20% FSBM and 20%SPC resulted in a substantial decrease in unit density by 9.2 and 24%, but an increase in lightness, greenness, yellowness, and expansion ratio of the extrudates by 7, 27, 14, 7, 17, 34, 15, and 16.5%, respectively. SPC inclusion led to a considerable increase in water absorption, thermal resistivity, and thermal diffusivity by 17.5, 6.3, and 17.6%, respectively, whereas no significant change was observed for these properties with incorporation of 20% FSBM. Additionally, all extruded products had high durability. Taken together, using ~30% DDG with 20% FSBM or 20% SPC as alternative protein sources resulted in viable extrudates with properties appropriate for yellow perch production. A future study investigating the effect of extrusion processing conditions on the production of complete vegetable-based protein feeds for yellow perch species would be appropriate

    Modeling Single-Screw Extrusion Processing Parameters and Resulting Extrudate Properties of DDGS-Based Nile Tilapia (Oreochromis niloticus) Feeds

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    A single-screw laboratory extruder was used to conduct an L18 (22´ 36) Taguchi fractional factorial study of aquafeed processing. The ingredients were based on a formulation for nutritionally-balanced Nile tilapia diets containing distillers dried grains with solubles (DDGS) and soybean meal as the main protein sources, in addition to constant amounts of corn flour, whey, and fishmeal. The effects of three levels of DDGS (20, 30 and 40%), soybean meal (30, 40 and 50%), ingredient moisture content (20, 30 and 40% db), screw speed (100, 150 and 200 rpm), die dimension (L/D ratios of 5, 9 and 13), barrel temperature (80-100-100°C, 80-120-120°C and 80-140-140°C) and two levels of screw configuration (compression ratios of 2:1 and 3:1) on extrudate physical properties (moisture content, water activity, bulk density, unit density, expansion ratio, pellet durability index, water absorption and solubility indices, water stability, color) and extruder processing parameters (resulting temperatures, die pressure, extruder torque, mass flow rate, apparent viscosity, and specific mechanical energy) were determined. Data from raw materials, processing conditions, and extrudate properties were used to develop surface response curves and equations. However, predominantly low R2values (\u3c 0.5) only permitted linear relationships between some independent parameters and response variables. Regarding main effects, die pressure significantly decreased with higher DDGS levels, moisture content, temperature, lower die L/D, and higher screw compression. Expansion ratio decreased significantly with higher moisture content and lower die L/D. Significant differences in color were caused by changes in DDGS levels and moisture content. In summary, DDGS, moisture content, die dimension, and extrusion conditions had the biggest impact on most of the extrudate physical properties and processing conditions. Different combinations of these independent factors can be used to achieve desired extrudate physical properties and processing conditions

    A Comparative Study of the Effects of Non-starch Polysaccharide Gums on Physical Properties of Single-screw Extruded Aquafeed

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    A factorial experimental design (5Ă—3Ă—2) was used to investigate the effects of non-starch polysaccharide binding agents on physical properties of single-screw extrusion. Extrusion cooking trials were performed with an ingredient blend for yellow perch, fortified with five non-starch polysaccharide binding agents including three plant-origin gums (guar, wheat gluten, carboxymethyl cellulose (CMC)) and two microbial-origin exopolysaccharide gums (xanthan and pullulan), with three levels of gum inclusion (3, 6, and 10%), and two levels of screw speed (100 and 150 rpm). Effects of the independent variables on extrudate characteristics were extensively analyzed and included density, expansion ratio, water absorption and solubility indices, pellet durability, and color. Increasing gum level from 3 to 10% led to a considerable increase in unit density of extrudates for xanthan, guar, wheat gluten, CMC, and pullulan by 39.6%, 21%, 11.4%, 30%, and 19.7%, respectively. The minimum (357 kg m-3) and maximum (607 kg m-3) bulk densities were observed for the diets produced with 6% guar at 150 rpm and 10% xanthan at 100 rpm, respectively. The mean values of expansion ratio for the diets containing exopolysaccharide gums were slightly smaller than those of the other diets. Increasing gum inclusion level increased the expansion ratio of the extrudates using xanthan, wheat gluten and pullulan but reduced the expandability of diets used guar gum; increased levels did not change the expansion ratio of extrudates containing CMC. At the highest levels of gum inclusion and screw speed, both pullulan and wheat gluten gums provided better expandability of the feed extrudate. Exopolysaccharide gums resulted in extrudates with significantly higher pellet durability and water solubility indices. Overall, the addition of 6 to 10% non-starch exopolysaccharides could improve the pellet durability of aqua feed extrudates. A future study investigating the effects of feed composition and additional extrusion processing conditions on the physical parameters of these products in aquafeeds would be appropriate

    Twin-Screw Extrusion Processing of Rainbow trout (Oncorhynchus mykiss) Feeds Using Graded Levels of High Protein Corn-Based Distillers Dried Grains (HP-DDG) and Conventional Distillers Dried Grains with Solubles (DDGS)

    Get PDF
    Twin-screw extrusion cooking trials were performed to investigate the differential effects of conventional DDGS (DDGS) and HP-DDG inclusion, as fishmeal replacers, on physical properties (moisture content, water activity, thermal properties, expansion ratio, unit density, bulk density, water absorption, solubility and pellet durability indices, and color) of Rainbow trout (Oncorhynchus mykiss) feed. Four ingredient blends were formulated with 20 and 40% C- DDGS, and 20 and 40% HP-DDG, along with other required dietary ingredients. Each diet was extruded using two replications; a fishmeal based diet acted as the control diet. The highest and the lowest extrudate moisture content and water activity were observed for the diets containing 20% DDGS and 40% HP-DDG, respectively. Compared to the control diet, increasing HP-DDG content from 20 to 40% had no effect on the bulk density of the products, while increasing DDGS content from 20-40% led to a considerable rise in bulk density of the extrudates by 14.2 and 6%, respectively. Also, extrudates with the lowest brightness, greenness, and yellowness values were obtained from the diet containing 20% DDGS, whereas the most color intensity values were observed for the diets containing 40% DDGS and 20% HP-DDG. Increasing DDGS and HP-DDG from 0-40% caused a remarkable increase in water absorption index, by 72 and 30%, respectively. Likewise, the water solubility index increased, but in a considerably lesser order of magnitude. High pellet durability index of more than 99% was achieved with inclusion of either DDGS or HP-DDG. None of the diets impacted the thermal properties of the extrudates. Inclusion of 20 and 40% DDGS resulted in the extrudates with the largest and the smallest unit density values of nearly 887 and 750 kg/m3, respectively. As was expected, expansion ratio decreased with increasing unit density. Increasing inclusion levels of HP-DDG did not show any effect on unit density or expansion ratio of the products. Future research should concentrate on investigating the effects of both extrusion processing and graded levels of different types of DDGS on Rainbow trout feeds

    The relationship between spiritual health and social trust among students

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    Social trust and spiritual health play an important role in social communication. The aim of this study was to determine the relationship between spiritual health and social trust among Iranian students. This cross-sectional study was conducted in the city of Sanandaj, in the West of Iran, in 2018. 686 students from 5 universities were included in the study through simple random sampling. The data were collected using established, reliable instruments for the assessment of social trust and spiritual health. Logistic regression models were applied to assess the association between social trust and spiritual health. We reported estimated logits and Odds Ratios (OR) with corresponding 95% confidence intervals (95% CI). The students with a literate father had substantially higher odds of social trust (OR=1.98, 95% CI=1.19-3.28, p\u3c0.01). Also, similar findings were obtained for students with a literate mother compared to those with an illiterate mother (OR=2.09, 95% CI=1.33-3.28, p\u3c0.01). The odds of social trust also increased with the father’s employment status (OR=13.06, 95% CI=4.16-41, p\u3c0.01). The odds of social trust increased with religious health (OR=1.05, 95% CI=1.03-1.08, p\u3c0.01). It is essential to increase spiritual health and the parents’ literacy to promote social trust among the students

    Twin-screw Extrusion Processing of Vegetable-based Protein Feeds for Yellow Perch (Perca flavescens) Containing Distillers Dried Grains, Soy Protein Concentrate, and Fermented High Protein Soybean Meal

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    Changing to alternative protein sources supports production of more economic aquafeeds. Two isocaloric (3.06 kcal/g) and isonitrogenous (40% db) experimental feeds for juvenile yellow perch were formulated with incorporation of fermented soybean meal (FSBM) and soy protein concentrate (SPC), each of which were at two levels (0 and 20% db), along with constant amounts of high protein distillers dried grains (DDG) (~30% db), and appropriate amounts of other ingredients. Using a pilot scale twin-screw extruder, feed production was performed in two replications for each diet at conditioner steam levels of 0.11 to 0.16 kg/min, extruder water of 0.11 to 0.19 kg/min, and screw speeds of 230 to 300 rpm. The effects of SPC and FSBM inclusion on extrudate physical properties were compared with those of a control diet (which contained 20% fishmeal and ~30% DDG). Inclusion of 20% FSBM and 20%SPC resulted in a substantial decrease in unit density by 9.2 and 24%, but an increase in lightness, greenness, yellowness, and expansion ratio of the extrudates by 7, 27, 14, 7, 17, 34, 15, and 16.5%, respectively. SPC inclusion led to a considerable increase in water absorption, thermal resistivity, and thermal diffusivity by 17.5, 6.3, and 17.6%, respectively, whereas no significant change was observed for these properties with incorporation of 20% FSBM. Additionally, all extruded products had high durability. Taken together, using ~30% DDG with20% FSBM or20% SPC as alternative protein sources resulted in viable extrudates with properties appropriate for yellow perch production. A future study investigating the effect of extrusion processing conditions on the production of complete vegetable-based protein feeds for yellow perch species would be appropriate

    Imaging a Single-Electron Quantum Dot

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    Images of a single-electron quantum dot were obtained in the Coulomb blockade regime at liquid He temperatures using a cooled scanning probe microscope (SPM). The charged SPM tip shifts the lowest energy level in the dot and creates a ring in the image corresponding to a peak in the Coulomb-blockade conductance. Fits to the lineshape of the ring determine the tip-induced shift of the electron energy state in the dot. SPM manipulation of electrons in quantum dots promises to be useful in understanding, building and manipulating circuits for quantum information processing.Comment: 14 pages including 3 figure
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