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91.
Use of Cottonseed Meal in Channel Catfish Feeds 总被引:3,自引:0,他引:3
Solvent extracted cottonseed meal was substituted for soybean meal in catfish feeds on a nitrogen basis. The feeds, which contained either 0, 10, or 20% cottonseed meal, were formulated to contain about 32% protein and 2.9 kcal digestible energy/g. The fish were reared in 6 m3 net pens suspended in a 1.6 ha earthen pond. Twelve pens (four per treatment) were stocked with 400 fish with an initial average weight of 95 g/fish. All fish were fed to satiation once daily. A sample of 60 fish from each pen was weighed at 76 days to evaluate feed consumption, feed conversion, and weight gain. At the end of the experiment (132 days), fish from each net pen were weighed collectively and samples were taken to determine tissue free gossypol concentrations, proximate composition of fillets, and dressout percentages. There were no significant differences in weight gain, feed conversion, or survival of fish sampled at 76 days or of fish at the end of the experiment regardless of dietary treatment. At 76 days, feed consumption of fish fed the 20% cottonseed meal feed was significantly higher than that of other fish, but there were no significant differences in feed consumption at the end of the experiment. Free gossypol levels were below detectable limits in fish tissue. There were no significant differences in percentage dressout or in body composition, except for a slightly higher ash content in fish fed the feed containing 10% cottonseed meal. It appears that cottonseed meal can be used to partially substitute for soybean meal in catfish feeds. At the present, it is recommended that cottonseed meal be limited to 15% of the catfish diet. 相似文献
92.
A high incidence of Diplodia shoot blight (site means ranging 85-100%) was observed on recently planted red pine (Pinus resinosa) seedlings where mature red pine stands previously had been clearcut. An investigation of the potential of harvest debris as a source of inoculum of Diplodia pathogens then was conducted. Cones, bark, needles, stems from shoots bearing needles, and stems from shoots not bearing needles (both suspended above the soil and in soil contact) were collected from harvest debris left at sites where clearcutting occurred. Conidia were quantified, and their germination rate was assessed, and Diplodia species were identified using PCR. Conidia of Diplodia species were found at all study sites and conidia counts increased from samples collected from 6 to 18 months after harvest. Germinable conidia were obtained from debris collected 6 months to 5 years after harvest. Fewer conidia were obtained from debris collected at intervals of up to 4-5 years after harvest and the percentage of germinable conidia was lower after longer intervals following harvest. More conidia were obtained and a greater percentage germinated from debris collected above the soil than from debris in soil contact. The host substrate also influenced the number of conidia and the percentage that germinated. Planting red pine seedlings next to debris infested with Diplodia pathogens could provide a persistent source of inoculum. Results should prompt further consideration by land managers and researchers of the potential forest health risks, in addition to benefits, that may be associated with harvest debris. 相似文献
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Luo Z Murray BS Yusoff A Morgan MR Povey MJ Day AJ 《Journal of agricultural and food chemistry》2011,59(6):2636-2645
It has been shown that some common food flavonoids can act as excellent stabilizers of oil-in-water emulsions through their adsorption as water-insoluble particles to the surface of the oil droplets, i.e., Pickering emulsions are formed. Flavonoids covering a wide range of octanol-water partition coefficients (P) were screened for emulsification behavior by low shear mixing of flavonoid+n-tetradecane in a vortex mixer. Most flavonoids with very high or very low P values were not good emulsifiers, although there were exceptions, such as tiliroside, which is very insoluble in water. When a high shear jet homogenizer was used with 20 vol% oil in the presence of 1 mM tiliroside, rutin, or naringin, much finer emulsions were produced: the average droplet sizes (d32) were 16, 6, and 5 μm, respectively. These results may be highly significant with respect to the delivery of such insoluble compounds to the gut, as well as their digestion and absorption. 相似文献
95.
Murray BS Durga K de Groot PW Kakoulli A Stoyanov SD 《Journal of agricultural and food chemistry》2011,59(24):13277-13288
Surface active cellulose particles have been prepared for use as foam stabilizing agents in foods. Various sources of cellulose were broken down by combinations of milling, acid dissolution and treatment with cellulase. The most efficient and simple method was hammer and freezer milling of dry crystalline α-cellulose (Tencel). The resultant Tencel particles were made partially hydrophobic through precipitation of ethyl cellulose (EC) onto them in acetone-water dispersions. The optimum ratio of EC to cellulose and the optimum solids concentration (C(x)) at which to form the complexes were 1:1 and C(x) ≈ 1 wt %, respectively. Complexes combined at low concentrations (e.g., C(x) ≈ 0.1 wt %) with caseins or whey proteins gave significant improvements in stability of foams and bubbles to coalescence and disproportionation compared to either component alone. As such, the complexes could be a useful ingredient in improving the quality of various food foams. 相似文献
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Hydrophilic biopolymer systems reach a state of maximum plasticization at a concentration of water designated as Wg′. The thermomechanical behaviour of various extruded cereals were investigated at concentrations above and below Wg′ to determine the significance of Wg′ on the viscoelastic properties in the rubbery region above Tg. Cereal melts were produced via extrusion cooking using a twin-screw extruder at in-barrel moisture contents ranging from 25 to 42% (wb). Dynamic mechanical thermal analysis (DMTA) was used to determine the viscoelastic properties for melts obtained from degermed corn meal, oat flour, pregelatinized corn starch and pregelatinized waxy maize. All of the extruded melts displayed reductions in the storage modulus of about two orders of magnitude from the glassy to rubbery regimes. At temperatures greater than 320K, another transition is apparent for extruded oat flour. These losses may be attributed to a reduction in physical crosslinks and/or entanglements. With respect to the other melts investigated, differences in the oat flour melts at temperatures above Tgmay be due to the increased presence of protein and lipid. Given the apparent partly crystalline nature of these melts at moisture contents <Wg′, the most appropriate representation of the viscoelastic properties may be isotimic plots of the viscoelastic functions. These contour plots provide a more comprehensive guide to material behaviour than the ‘traditional’ state diagrams found throughout the literature. An important point is that prediction of viscoelastic properties above Tgfor polymers where the internal structure changes with temperature or moisture content, cannot be predicted using the same methods of reduced variables as for amorphous polymers. Thus rather than using these methods, experimental data, such as given here, may prove to be necessary to design or understand processes involving cereal melts based on their viscoelastic properties. 相似文献
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Pure compound screening has previously identified the indolglyoxylamidospermidine ascidian metabolites didemnidine A and B (2 and 3) to be weak growth inhibitors of Trypanosoma brucei rhodesiense (IC50 59 and 44 μM, respectively) and Plasmodium falciparum (K1 dual drug resistant strain) (IC50 41 and 15 μM, respectively), but lacking in selectivity (L6 rat myoblast, IC50 24 μM and 25 μM, respectively). To expand the structure–activity relationship of this compound class towards both parasites, we have prepared and biologically tested a library of analogues that includes indoleglyoxyl and indoleacetic “capping acids”, and polyamines including spermine (PA3-4-3) and extended analogues PA3-8-3 and PA3-12-3. 7-Methoxy substituted indoleglyoxylamides were typically found to exhibit the most potent antimalarial activity (IC50 10–92 nM) but with varying degrees of selectivity versus the L6 rat myoblast cell line. A 6-methoxyindolglyoxylamide analogue was the most potent growth inhibitor of T.
brucei (IC50 0.18 μM) identified in the study: it, however, also exhibited poor selectivity (L6 IC50 6.0 μM). There was no apparent correlation between antimalarial and anti-T. brucei activity in the series. In vivo evaluation of one analogue against Plasmodium berghei was undertaken, demonstrating a modest 20.9% reduction in parasitaemia. 相似文献