967 resultados para Oil yield
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Mechanisms underlying milk fat conjugated linoleic acid (CLA) responses to supplements of fish oil were investigated using five lactating cows each fitted with a rumen cannula in a simple experiment consisting of two consecutive 14-day experimental periods. During the first period cows were offered 18 kg dry matter (DM) per day of a basal (B) diet formulated from grass silage and a cereal based-concentrate (0.6 : 0.4; forage : concentrate ratio, on a DM basis) followed by the same diet supplemented with 250 g fish oil per day (FO) in the second period. The flow of non-esterified fatty acids leaving the rumen was measured using the omasal sampling technique in combination with a triple indigestible marker method based on Li-Co-EDTA, Yb-acetate and Cr-mordanted straw. Fish oil decreased DM intake and milk yield, but had no effect on milk constituent content. Milk fat trans-11C(18:1), total trans-C-18:1, cis-9 trans-11 CLA, total CLA, C-18 :2 (n- 6) and total C-18:2 content were increased in response to fish oil from 1.80, 4.51, 0.39, 0. 56, 0.90 and 1.41 to 9.39, 14.39, 1.66, 1.85, 1.25 and 4.00 g/100 g total fatty acids, respectively. Increases in the cis-9, trans-11 isomer accounted for proportionately 0.89 of the CLA response to fish oil. Furthermore, fish oil decreased the flow of C-18:0 (283 and 47 g/day for B and FO, respectively) and increased that of trans-C-18:1 fatty acids entering the omasal canal (38 and 182 g/day). Omasal flows of trans-C-18:1 acids with double bonds in positions from delta-4 to -15 inclusive were enhanced, but the effects were isomer dependent and primarily associated with an increase in trans-11C(18:1) leaving the rumen (17.1 and 121.1 g/day for B and FO, respectively). Fish oil had no effect on total (4.36 and 3.50 g/day) or cis-9, trans-11 CLA (2.86 and 2.08 g/day) entering the omasal canal. Flows of cis-9, trans-11 CLA were lower than the secretion of this isomer in milk. Comparison with the transfer of the trans-9, trans-11 isomer synthesized in the rumen suggested that proportionately 0.66 and 0.97 of cis-9, trans-11 CLA was derived from endogenous conversion of trans-11 C-18:1 in the mammary gland for B and FO, respectively. It is concluded that fish oil enhances milk fat cis-9, trans-11 CLA content in response to increased supply of trans-11 C-18:1 that arises from an inhibition of trans C-18:1 reduction in the rumen.
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In this study was analyzed the effect of crop year and harvesting time on the fatty acid composition of cv. Picual virgin olive oil. The study was carried out during the fruit ripening period for three crop seasons. The mean fatty acid composition of Picual oils was determined. The oils contained palmitic acid (11.9%), oleic acid (79.3%), and linoleic acid (2.95%). The content of palmitic acid and saturated fatty acids decreased during fruit ripening while oleic and linoleic acids increased. The amount of stearic and linolenic acids decreased. The amount of saturated acids, palmitic and stearic, and the polyunsaturated acids linoleic and linolenic was dependent on the time of harvest, whereas the amount of oleic acid varied with the crop year. The differences observed between crop years for both palmitic and linoleic acid may be explained by the differences in the temperature during oil biosynthesis and by the amount of summer rainfall for oleic acid content. A significant relationship was observed between the MUFA/PUFA ratio and the oxidative stability measured by the Rancimat method.
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Background: Up to 75% of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production. Methods: We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat) located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient fromsimple to heterogeneous landscapes. Results: Insect pollination enhanced average crop yield between 18 and 71% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries’ commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness. Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild pollinators in some areas, but our results suggest the need of landscape-scale actions to enhance wild pollinator populations.
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Tiger nut (Cyperus esculentus) tuber contains oil that is high in monounsaturated fatty acids, and this oil makes up about 23% of the tuber. The study aimed at evaluating the impact of several factors and enzymatic pre-treatment on the recovery of pressed tiger nut oil. Smaller particles were more favourable for pressing. High pressure pre-treatment did not increase oil recovery but enzymatic treatment did. The highest yield obtained by enzymatic treatment prior to mechanical extraction was 33 % on a dry defatted basis, which represents a recovery of 90 % of the oil. Tiger nut oil consists mainly of oleic acid; its acid and peroxide values reflect the high stability of the oil.
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Regulatory, safety, and environmental issues have prompted the development of aqueousenzymatic extraction (AEE) for extracting components from oil-bearing materials. The emulsion resulting from AEE requires de-emulsification to separate the oil; when enzymes are used for this purpose, the method is known as aqueous enzymatic emulsion de-emulsification (AEED). In general, enzyme assisted oil extraction is known to yield oil having highly favourable characteristics. This review covers technological aspects of enzyme assisted oil extraction, and explores the quality characteristics of the oils obtained,focusing particularly on recent efforts undertaken to improve process economics by recovering and reusing enzymes.
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The main goal of this work was to evaluate thermodynamic parameters of the soybean oil extraction process using ethanol as solvent. The experimental treatments were as follows: aqueous solvents with water contents varying from 0 to 13% (mass basis) and extraction temperature varying from 50 to 100 degrees C. The distribution coefficients of oil at equilibrium have been used to calculate enthalpy, entropy and free energy changes. The results indicate that oil extraction process with ethanol is feasible and spontaneous, mainly under higher temperature. Also, the influence of water level in the solvent and temperature were analysed using the response surface methodology (RSM). It can be noted that the extraction yield was highly affected by both independent variables. A joint analysis of thermodynamic and RSM indicates the optimal level of solvent hydration and temperature to perform the extraction process.
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The catalytic ethanolysis of soybean oil with commercial immobilized lipase type B from Candida antarctica to yield ethyl esters (biodiesel) has been investigated. Transesterification was monitored with respect to the following parameters: quantity of biocatalyst, reaction time, amount of water added and turnover of lipase. The highest yields of biodiesel (87% by (1)H NMR; 82.9% by GC) were obtained after a reaction time of 24 h at 32 degrees C in the presence of lipase equivalent to 5.0% (w/w) of the amount of soybean oil present. The production of ethyl esters by enzymatic ethanolysis was not influenced by the addition of water up to 4.0% (v/v) of the alcohol indicating that it is possible to use hydrated ethanol in the production of biodiesel catalyzed by lipase. The immobilized enzyme showed high stability under moderate reaction conditions and retained its activity after five production cycles. The (1)H NMR methodology elaborated for the quantification of biodiesel in unpurified reaction mixtures showed good correlations between the signal areas of peaks associated with the alpha-methylene groups of the ethyl esters and those of the triacyl-glycerides in residual soybean oil. Monoacylglycerides, diacylglycerides and triglycerides could also be detected and quantified in the crude biodiesel using (1)H NMR spectroscopic and GC-FID chromatographic methods. The biodiesel production by enzymatic catalysis was promising. In this case, was produced a low concentration of glycerol (0.74%) and easily removed by water extraction. (C) 2010 Elsevier B.V. All rights reserved.
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Pseudomonas aeruginosa LBI produced surface active rhamnolipids when cultivated on waste from the sunflower-oil process under different conditions. These biosurfactants, which reduce the superficial and interfacial tensions between fluids, offer advantages over their chemical counterparts, especially because of their ecological acceptability. These molecules can be used in fields as diverse as chemical, pharmaceutical and petrochemical industries. In this work, we present the effect of C/N ratio on growth and production yield. The best production yields (Y-P/S) were achieved for C/N ratios (in g/g) of 8/1 (0.22) and 6.4/1 (0.23). The product concentration was very satisfactory (7.3 g/L) at C/N ratio of 8/1, especially when considering that the substrate was basically composed of wastes that would otherwise constitute an environmental disposal problem. (c) 2007 Elsevier Ltd. All rights reserved.
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Effect of lactic acid, SO2, temperature, and their interactions were assessed on the dynamic steeping of a Brazilian dent corn (hybrid XL 606) to determine the ideal relationship among these variables to improve the wet-milling process for starch and corn by-products production. A 2x2x3 factorial experimental design was used with SO2 levels of 0.05 and 0.1% (w/v), lactic acid levels of 0 and 0.5% (v/v), and temperatures of 52, 60, and 68degreesC. Starch yield was used as deciding factor to choose the best treatment. Lactic acid added in the steep solution improved the starch yield by an average of 5.6 percentage points. SO2 was more available to break down the structural protein network at 0.1% than at the 0.05% level. Starch-gluten separation was difficult at 68degreesC. The lactic acid and SO2 concentrations and steeping temperatures for better starch recovery were 0.5, 0.1, and 52degreesC, respectively. The Intermittent Milling and Dynamic Steeping (IMDS) process produced, on average, 1.4% more starch than the conventional 36- hr steeping process. Protein in starch, oil content in germ, and germ damage were used as quality factors. Total steep time can be reduced from 36 hr for conventional wet-milling to 8 hr for the IMDS process.
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The objective of this study was to determine the energy values of soybean oil (SBO) and tallow (T) combined in different ratios, and to evaluate their effects on the performance, body composition, and serum lipid levels of starter broilers. In experiment I, a digestibility trial was performed to determine the energy value of the SOB and T mixtures using 100 12 - to 21 -day-old broilers. In experiment II, 930 one-day-old broilers were used. Treatments consisted of the inclusion of 4% SBO and T inclusions at the following ratios: 0:100, 25:75, 50:50, 75:25, 100:0. Each treatment included six replicates. In experiment I, AME and AMEn linearly increased (P<0.01), as SBO participation in the mixture increased. In experiment II, the different lipid ratios quadratically influenced (P<0.01) body weight and weight gain at 21 days of age, increasing up to the ratio of 65.87:34.13. Serum lipids linearly decreased (P<0.05) as SOB inclusion in the diet increased. It was concluded that AME and AMEn of SBO and T at ratios of 0:100, 25:75, 50:50, 75:25, and 100:0 were 7.882 and 7.542, 8.384 and 8.076, 8.701 and 8.385, 8.801 and 8.727, and 9.478 and 9.271 kcal/kg, respectively. The best performance with no detrimental effect on carcass yield was obtained with the mixture of 75% SBO with 25% T. The highest dietary soybean oil level reduced serum lipid levels of 21-day-old broilers.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This work has been developed using a sylvestral fruit tree, native to the Brazilian forest, the Eugenia uniflora L., one of the Mirtaceae family. The main goal of the analytical study was focused on extraction methods themselves. The method development pointed to the Clevenger extraction as the best yield in relation to SFE and Soxhlet. The SFE method presented a good yield but showed a big amount of components in the final extract, demonstrating low selectivity. The essential oil extracted was analyzed by GC/FID showing a large range of polarity and boiling point compounds, where linalool, a widely used compound, was identified. Furthermore, an analytical solid phase extraction method was used to clean it up and obtain separated classes of compounds that were fractionated and studied by GC/FlD and GUMS. (c) 2006 Elsevier B.V. All rights reserved.
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The proposal of this work was to study the effects of lecithin and soy oil on the fermentative performance of Saccharomyces uvarum I Z 1904, a yeast used in the industrial production of ethanol. High Test Molasses (HTM) was chosen as the fermentation media because it is a substratum that is poor in nutrients, and because it permits one to distinguish the action of lipids from other nutritional factors. The study of the optimization of the concentration of lipids by surface response analysis showed that the lipids favor the performance of the yeast principally when applied separately. Maximum concentrations of the two sources of lipids in the media stimulated the budding rate but did not constitute a protection against cell death. Considering the action of lipids on the cellular parameters studied, the supplementation of the media with 3.0 g/l of soy oil permitted the obtention of maximum responses of cellular viability, budding rate and viability of the buds after 6 successive cycles. In relation to the fermentative parameters, the use of 1.5 g/l of soy oil provided high yields and an equilibrium between the mass of ethanol produced (EM) and the alcoholic yield (Y p/s) , whereas the cellular viability after 6 cycles did not differ statistically from that observed with 3g/l of oil.
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This experiment was carried out at Plant Production Sector, Agronomical Science College-Botucatu, S.P., Brazil, in March, 2000. The aim of this assay was to determine the yield of essential oil of fennel (Foeniculum vulgare Miller) in different stages of development. Essential oils were prepared by hydrodistillation from the seeds using of Clevenger apparatus. The water utilized for the extraction of essential oil was sufficient to cover 100 g of seeds and the mixture was distilled for three hours. The volume of essential oil in the graduated side -arm of Clevenger apparatus was observed. There were no significative difference statistic was observed (Tukey 5%) in percentage (v/m) of oil content, based on dry weight of green seeds compared with dry weight of mature seeds, when they were harvested in two different stages of development. There was significative difference statistic between data obtained of humidity content of green seeds when these were compared with mature seeds. These results shows that others specifics studies about adaptation of fennel in tropical conditions are necessary, because the obtained data were different of data described on literature.
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Oil wastes were evaluated as alternative low-cost substrates for the production of rhamnolipids by Pseudomonas aeruginosa LBI strain. Wastes obtained from soybean, cottonseed, babassu, palm, and corn oil refinery were tested. The soybean soapstock waste was the best substrate, generating 11.7 g/L of rhamnolipids with a surface tension of 26.9 mN/m, a critical micelle concentration of 51.5 mg/L, and a production yield of 75%. The monorhamnolipid RhaC10C10 predominates when P. aeruginosa LBI was cultivated on hydrophobic substrates, whereas hydrophilic carbon sources form the dirhamnolipid Rha2C10C10 predominantly. © 2005 American Chemical Society and American Institute of Chemical Engineers.