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331.
A fractional factorial design with a replicated central composite point was used to investigate the effects of extrusion processing on physical properties of distillers dried grains with solubles (DDGS) based aquafeeds using a twin‐screw extruder. Extrusion cooking trials were performed with a nutritionally balanced ingredient blend for Nile tilapia, with two levels of screw speed (350 and 450 rpm), two levels of extruder water (0.236 and 0.302 kg/min), and two levels of conditioner steam (0.1 and 0.15 kg/min). The central point was 400 rpm screw speed, 0.271 kg/min extruder water, and 0.12 kg/min conditioner steam. Effects of these processing conditions on extrudate characteristics were extensively analyzed and included moisture content, water activity, thermal properties, expansion ratio, unit density, bulk density, color, water stability, sinking velocity, water absorption and solubility indices, and pellet durability index. Increasing the extruder water and conditioner steam resulted in a 5.3% decrease and nearly 8.6% rise in mass flow rate, respectively. As screw speed increased from 350 to 400 rpm, water stability and water activity increased by 13 and 58%, respectively. Increasing extruder water from 0.236 to 0.302 kg/min led to a significant increase in water stability by 12.5% and decreases in water absorption index, water activity, and expansion ratio by 13, 21, and 5.5%, respectively. As conditioner steam increased from 0.1 to 0.15 kg/min, sinking velocity and water absorption index decreased by 25 and 15%, respectively. Increasing conditioner steam from 0.1 to 0.12 kg/min resulted in 20, 5.5, 10, and 3% decreases in moisture content of the extrudates, brightness (L*), water stability, and expansion ratio, respectively. It also increased bulk density by 5.8% and unit density by 4.2%. Overall, all trials produced viable extrudates with properties appropriate for Nile tilapia feeding.  相似文献   
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333.
Genetic Resources and Crop Evolution - In the present study, the phenological and genetic differences/similarities of 95 walnut genotypes were considered. These genotypes had been propagated...  相似文献   
334.
A headspace (HS)-trap method in combination with gas chromatography (GC)-mass spectrometry (MS) was developed for the determination of volatile constituents in hops. The highly sensitive HS-trap system reduces the detection limit by using up to four trap enrichment cycles. Seventy hop samples of different varieties and cultivation regions, from the 2008 harvest, were examined using the HS-trap-GC-MS method and the established "European Brewery Convention" (EBC) method for hop essential oil analysis. Twenty-one different volatiles were quantified for each hop sample. For all compounds, except caryophyllene oxide, a strong correlation was found between the results of the HS-trap method and the EBC method. Experiments have revealed that the EBC method using steam distillation is not appropriate for thermolabile compounds, such as caryophyllene oxide, due to decomposition during boiling. The HS-trap method is fast and sensitive, requires small sample amounts and minimal sample preparation, and is easy to apply.  相似文献   
335.
The grafting of melon plants onto cucurbit rootstocks is a common commercial practice in many parts of the world. However, certain cucurbits have been shown to accumulate large quantities of weathered persistent organic pollutants from the soil, and the potential contamination of grafted produce has not been thoroughly evaluated. Large pot and field experiments were conducted to assess the effect of grafting on accumulation of weathered DDX (the sum of p,p'-DDT, p,p'-DDD, and p,p'-DDE) from soils. Intact squash (Cucurbita maxima × moschata) and watermelon (Citrullus lanatus), their homografts, and compatible heterografts were grown in pots containing soil with weathered DDX at 1480-1760 ng/g soil or under field conditions in soil at 150-300 ng/g DDX. Movement of DDX through the soil-plant system was investigated by determining contaminant levels in the bulk soil and in the xylem sap, roots, stems, leaves, and fruit of the grafted and nongrafted plants. In all plants, the highest DDX concentrations were detected in the roots, followed by decreasing amounts in the stems, leaves, and fruit. Dry weight concentrations of DDX in the roots ranged from 7900 ng/g (intact watermelon) to 30100 ng/g (heterografted watermelon) in the pot study and from 650 ng/g (intact watermelon) to 2430 ng/g (homografted squash) in the field experiment. Grafting watermelon onto squash rootstock significantly increased contaminant uptake into the melon shoot system. In the pot and field studies, the highest stem DDX content was measured in heterografted watermelon at 1220 and 244 ng/g, respectively; these values are 140 and 19 times greater than contaminant concentrations in the intact watermelon, respectively. The xylem sap DDX concentrations of pot-grown plants were greatest in the heterografted watermelon (6.10 μg/L). The DDX contents of the leaves and fruit of watermelon heterografts were 3-12 and 0.53-8.25 ng/g, respectively, indicating that although the heterografted watermelon accumulated greater pollutant levels, the resulting contamination is not likely a food safety concern.  相似文献   
336.
This study was carried out in order to determine the effect of various manganese fertilizers [manganese sulfate (MnSO4.3H2O) (MS), 27% manganese (Mn) and manganese ethylenediaminetetraacetic acid (Mn-EDTA) (ME), 12% Mn], their doses (0, 6, 9, 12 mg Mn kg?1 for the soil and 0, 0.2, 0.3, 0.4% for the leaf) on yield and net return of dwarf bean. Field experiments were conducted in the randomized blocks split plot design with four replications under Konya ecological conditions in Turkey. Soil applications were made on bands as a single application at sowing whereas foliar applications (FA) were made at two times. Results of the field experiments showed the highest bean yields were significantly obtained by the fertilizer of ME-FA sprayed (243.80 and 257.74 kg da?1). For both years, the lowest yields were obtained by the MS-SA applications (166.97 and 180.60 kg da?1). The maximum net income was US $104.16 da?1 and US $156.06 da?1 by years.  相似文献   
337.
Fast transport system of materials in mammalian nerve fibers   总被引:4,自引:0,他引:4  
A fast transport system of materials is shown in cat sensory fibers of sciatic nerve. After injection of tritiated leucine into the lumbar seventh ganglia, the distribution of activity was measured in the sciatic nerves from 2 to 8 hours afterward. The distribution showed a crest of activity advancing down the fibers at a rate of approximately 410 millimeters per day. An intraaxonic locus of the activity was indicated by a block of the downflow induced by local freezing which causes the fibers to close off. Some of the activity in the nerve was due to free tritiated leucine, with most of it incorporated into polypeptide, soluble protein, and subcellular particulates.  相似文献   
338.
339.
Stone, disc and hammer milling of bulgur   总被引:1,自引:0,他引:1  
The effects on the milling quality of bulgur were compared using stone, disc and hammer mills. For each milling system bulgur particles were examined for appearance, surface structure, dimensions (max., min., mean, standard deviations and coefficient of variance), particle size distribution, bulk density and 1000 particle weight. Smooth and regular shaped bulgur particles were obtained using the abrasive stone and disc mills. Stone milled bulgur particles, were not split or glassy, but were opaque. Hammer milling significantly affected the appearance and surface characteristics of the bulgur particles and gave the lowest minimum dimensions and the highest deviation and variance in dimensions. The milling yields for hammer (98.3%) and stone (97.4%) mills were higher than for the disc mill (96.5%). Each mill gave a different distribution between coarse, medium and fine fractions. The highest yield of the coarse fraction (83.1%) was obtained using the stone mill. The results indicate that due to loss of quality, hammer milling is not suitable for bulgur preparation.  相似文献   
340.
The aim of this study is to assess the effects of Olive Oil Mill Wastewater (OOMW) application as irrigation water on in vitro pollen germination, focusing on total protein quantity. In test groups, pollen germination substances such as sucrose, H3BO3 and Ca(NO3)2 were added to different concentrations of OOMW and used as germination media. Regarding control group, the same substance melted into water instead of OOMW. As a result, in general, pollen germination percentage was decreased significantly in all OOMW concentrations than that of the control group, except 1/1000 concentrations. Similarly, total protein quantities declined linearly depending on decreasing OOMW concentrations, except 1/1 concentration which has 4-5 times the control value. Consequently, it was established that OOMW generally decreased pollen germination ratio and had carcinogenic effects on protein synthesis mechanism and must not be used as irrigation water without purification.  相似文献   
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