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1.
A method is described for determination of ellagitannins in ethanol-water extracts of oak wood and in distilled alcoholic beverages matured in oak barrels. It is based on the combined ellagic acid content according to ellagitannin structure. Hydrolysis was carried out in the presence of hydrochloric acid under reflux in a 100 degrees C oil bath for 3 h. Total ellagic acid was thus determined by liquid chromatography (LC), and the free ellagic acid content present in the ethanol-water media was subtracted, the difference being the combined ellagic acid content corresponding to ellagitannins. A 5 micron C18 column was used with detection at 254 nm. The method is specific for ellagitannins, which is an advantage over other analytical techniques for overall evaluation of these substances extracted from wood. Results for spirits distilled from wine, grain, and sugarcane were highly variable.  相似文献   

2.
Three new phenolic compounds named whiskey tannins A and B and carboxyl ellagic acid were isolated from commercial Japanese whiskey, along with gallic acid, ellagic acid, brevifolin carboxylic acid, three galloyl glucoses, a galloyl ester of phenolic glucoside, 2,3-(S)-hexahydroxydiphenoylglucose, and castacrenin B. Whiskey tannins A and B were oxidation products of a major oak wood ellagitannin, castalagin, in which the pyrogallol ring at the glucose C-1 position of castalagin was oxidized to a cyclopentenone moiety. These tannins originated from ellagitannins contained in the oak wood used for barrel production; however, the original oak wood ellagitannins were not detected in the whiskey. To examine whether the whiskey tannins were produced during the charring process of barrel production, pyrolysis products of castalagin were investigated. Dehydrocastalagin and a new phenolcarboxylic acid trislactone having an isocoumarin structure were isolated, along with castacrenin F and ellagic acid. However, whiskey tannins were not detected in the products.  相似文献   

3.
Detection and individual quantification of oak wood ellagitannins in oak barrel aged red wine samples are difficult mainly due to their low levels and the similarity between their structures. In this work, a quantification method using mass spectrometry has been developed and validated to quantify wine ellagitannins after sample fractionation with a previously reported method. The use of an internal standard is a requirement to correct mass signal variability. (-)-Gallocatechin, among the different tested compounds, was the only one that proved to be a suitable internal standard making possible the accurate and individual quantification of the main oak wood ellagitannins. The developed methodology has been used to detect and quantify these ellagitannins in different Spanish commercial wines, proving its usefulness.  相似文献   

4.
为缓解南方夏季高温高湿热应激对肉牛生产性能的影响,探讨不同降温方式对肉牛的降温效果。以江西省地方品种锦江黄牛为试验对象,试验分为3组,每组8头牛,试验1、2和3组分别为舍内通风组、舍内喷雾通风组和屋面喷淋通风组,3个组牛的平均体质量分别为(250.38±24.54)、(247.93±24.54)和(250.00±24.02)kg(P0.05),试验于2014年7—8月进行。分别测定了环境温度、湿度,肉牛直肠温度、呼吸频率和日增质量等,结果表明:屋面喷淋运行期间(10:00—18:00),与1组相比,3组舍内距屋顶0、1、2和3 m处温度分别降低4.79(P0.01)、2.13、1.37和1.42℃;湿度分别增加9.66%(P0.01)、6.76%(P0.01)、2.66%和1.80%;在14:00时,距离地面高度1.5和0.5 m分别降低1.20(P0.05)和1.07℃;呼吸频率降低12次/min(P0.01);直肠温度差异不显著;日增质量提高0.19 kg/d,提高率为26.38%(P0.05)。喷雾运行期间14:00时,与1组相比,2组肉牛体感温度喷雾前后分别降低0.51和1.43℃(P0.05),在18:00分别下降0.70和1.60℃(P0.05);呼吸频率降低13次/min(P0.01);直肠温度差异不显著;日增质量提高0.08 kg/d,提高率为11.11%。从以上结果可以看出,喷雾通风和屋面喷淋通风均可以一定程度缓解肉牛的热应激。  相似文献   

5.
The evolution of tannins in Spanish oak heartwood of Quercus robur L., Quercus petraea Liebl.,Quercus pyrenaica Wild., and Quercus faginea Lam. was studied in relation to the processing of wood in barrel cooperage. Their evolution was compared with that of French oak of Q. robur (Limousin, France) and Q. petraea (Allier, France) and American oak of Quercus alba L. (Missouri), which are habitually used in cooperage. Two stages of process were researched: the seasoning of woods during 3 years in natural conditions and toasting. Total phenol and total ellagitannin contents and optical density at 420 nm of wood extracts were determined. The ellagitannins roburins A-E, grandinin, vescalagin, and castalagin were identified and quantified by HPLC, and the molecular weight distribution of ellagitannins was calculated by GPC. During the seasoning process the different ellagitannin concentrations decreased according to the duration of this process and in the same way as those in French and American woods. The toasting process also had an important influence on the ellagitannin composition of wood. Roburins A-E, grandinin, vescalagin, and castalagin decreased during this process in the Spanish wood species, in the same proportion as in the French and American ones. Also, the seasoning and toasting processes lead to qualitative variations in the structure of ellagitannins, especially in the molecular weight distribution, as was evidenced by GPC analysis of their acetylated derivatives.  相似文献   

6.
Some wood substances such as ellagitannins can be extracted during wine aging in oak barrels. The level of these hydrolyzable tannins in wine depends of some parameters of oak wood. Their impact on the organoleptic perception of red wine is poorly known. In our research, oak staves were classified in three different groups according to their level of ellagitannins estimated by NIRS (near infrared spectroscopy) online procedure (Oakscan). First, the ellagitannin level and composition were determine for each classified stave and an excellent correlation between the NIRS classification (low, medium and high potential level of ellagitannin) and the ellagitannin content estimated by HPLC-UV was found. Each different group of NIRS classified staves was then added to red wine during its aging in a stainless tank, and the extraction and evolution of the ellagitannins were monitored. A good correlation between the NIRS classification and the concentration of ellagitannins in red wine aging in contact with the classified staves was observed. The influence of levels of ellagitannins on the resulting wine perception was estimated by a trained judge's panel, and it reveals that the level of ellagitannins in wine has an impact on the roundness and amplitude of the red wine.  相似文献   

7.
为探究适宜肉牛生长的最佳饲养密度,提高肉牛场经济效益,该文研究了饲养密度对肉牛生产性能,行为活动及经济效益的影响.在江西省高安市肉牛试验站选取体质量182~282 kg的杂交牛,在固定圈舍面积(18 m2)内分别饲养3、4、5、6、9头肉牛,对应占地面积为6.0、4.5、3.6、3.0、2.0 m2/头,饲养密度依次增加.由于肉牛体型较大,每个处理2个重复.结果显示,2.0 m2/头的试验组每头牛日采食量为11.90 kg显著高于其他处理组(P<0.05),但每头牛日增质量仅为1.09 kg;3.6 m2/头时,每头牛日采食量处于居中水平为10.96 kg,每头牛日增质量最佳,达到1.41 kg.随着饲养密度的增加,舍内二氧化碳浓度分别为1056.38、1108.44、1172.65、1200.89、1398.19 mg/m3,呈上升趋势;占地面积为2.0 m2/头时,舍内氨气浓度最高达3.23 mg/m3,而6.0 m2/头时仅为1.13 mg/m3;不同处理组之间有害气体浓度存在显著性差异(P<0.05).2.0 m2/头处理组1 d内站立时间(含打斗)为11.84 h,站立时间最长,脏污程度评分为2.09,体表最脏,3.6 m2/头试验组在打斗时间及体表清洁度方面均处于居中水平.综合上述指标,182~282 kg的每头牛适宜占地面积为3.6 m2,此时饲料转化率高,动物福利水平较好,利于农场取得较好经济效益.  相似文献   

8.
The decomposition of oak leaf litter was studied by means of a litterbag experiment in an oak forest in the Netherlands. The contribution of microbial activity and leaching to weight loss and element dynamics during the first 6 weeks of decomposition was investigated by means of frequent respiration measurements and extractions of the litter and by a qualitative comparison of throughfall and litter percolation water chemistry. The oak-leaf litter lost 9.3% of its initial dry weight during the first 6 weeks. In total, 90% of this observed weight loss was explained by the processes studied. About 5.9% (64% of the total) of this weight loss was attributed to microbial tespiration and 0.5% (5%) to the loss of inorganic solutes. Leaching of dissolved organic compounds was estimated to account for 2.0% (21%). The results indicated a fast leaching of K and Cl out of the fresh litter during the first 2 weeks, while Mg, Fe, Mn, Si, ortho P, and dissolved organic N were released at a much lower rate. At the same time, small amounts of H+, NH inf4 sup+ and NO inf3 sup- were retained in the litter.  相似文献   

9.
Perchlorate exposure and potential effects were evaluated in large mammals by monitoring heifer calves placed on a site with access to streamwater fed by a perchlorate-contaminated groundwater spring ( approximately 25 ng/mL). Blood was collected from the two calves on the site (and two control calves from an uncontaminated site) approximately every 2 weeks for analysis of perchlorate residues and thyroid hormones. During the 14 week study, perchlorate was detected (detection limit = 13.7 ng/mL) in blood plasma twice (15 ng/mL and 22 ng/mL) in one of the heifer calves drinking perchlorate-contaminated water on consecutive sampling periods 4 and 6 weeks after the beginning of perchlorate exposure. Constant exposure to 25 ppb perchlorate in drinking water had no effect on circulating thyroid hormones (T(3) and T(4)) in the heifer calves.  相似文献   

10.
 This study tested whether urban land use can affect the chemistry and decomposability of Quercus rubra L. (red oak) leaf litter in forests within and near a large metropolitan area. Cities may affect the quality of leaf litter directly through foliar uptake of atmospheric pollutants, and indirectly through alterations in local climate and changes in soil fertility caused by pollutant loads and altered nutrient cycling regimes. Using a microbial bioassay, we tested whether red oak leaf litter collected from urban and suburban forests in and near New York City differed in decomposability from litter of the same species collected from rural forests 130 km from the city. We found that oak litter from the urban forests decayed 25% more slowly and supported 50% less cumulative microbial biomass in a laboratory bioassay than rural litter. Rural litter contained less lignin and more labile material than urban litter, and the amounts of these chemical constituents were highly correlated with the decay rate coefficients and integrated microbial growth achieved on the litter. The specific causes of the variation in litter chemistry are not known. The results of this study suggest that decomposer activity and nutrient cycling in forests near large cities may be affected both by altered litter quality and by altered biotic, chemical and physical environments. The sensitivity of the microbial bioassay makes it useful for distinguishing differences in within-species litter quality that result from natural or anthropogenic variation in the environment. Received: 7 January 1999  相似文献   

11.
香蕉茎叶饲喂泌乳牛试验   总被引:9,自引:0,他引:9  
4头一胎泌乳 5个月的荷斯坦试验牛 ,在其日粮中用经青贮处理的香蕉茎叶 2 0 kg替代 60 %象草。经 60 d的试验结果表明 :试验组和对照组的泌乳量分别为 1 6.0 6kg和 1 5.36kg,乳脂率、乳蛋白质和乳的密度为 3.34、 3.0 9、 1 .0 2 51和 3.4 1、 3.0 7、 1 .0 2 65,两组牛的泌乳量和营养成分差异不显著 ( P>0 .0 5)。试验牛每产 1 kg鲜乳比对照组降低饲料费 0 .0 6元 ,试验期间两组牛体重变化和健康状况相似  相似文献   

12.
Background and Objective  Largely influenced by the passage of the Swamp Land Act of 1849, many wetlands have been lost in the coastal plain region of southeastern United States primarily as a result of drainage to convert land for agriculture. While further wetland conversion or loss is universally acknowledged, the process continues with little public recognition of the causes or consequences. This study examined changes in soil carbon, pH, and Mehlich extractable nutrients in soils following conversion of wetland to beef cattle pasture. Methods  To better understand the chemical response of soils during wetland conversion to beef cattle pasture, soil samples were collected from the converted beef cattle pastures and from the adjoining reference wetland. Soil samples were collected from eleven sites in the beef cattle pasture, and from four in the adjoining reference wetland. Data that were collected from the reference wetland sites were used as the reference/baseline data to detect potential changes in soil properties associated with the conversion of wetlands to beef cattle pastures from 1940 to 2002. Results and Discussion  Compared with the adjoining reference wetland, the beef cattle pasture soils in 2002, 62 years after being drained, exhibited: (1) a decrease in organic carbon, TOC (-172.3 g kg-1), nitrogen, TN (-10.1 g kg-1), water soluble phosphorus, WSP (-5.1mg kg-1), and potassium, K (-0.7 mg kg-1); (2) an increase in soil pH (+1.8 pH unit), calcium, Ca (+88.4 mg kg-1), magnesium, Mg (+7.5 mg kgc), manganese, Mn (+0.3 mg kg-1), and iron, Fe (+6.9 mg kg-1); and (3) no significant changes in sodium (Na), zinc (Zn), copper (Cu), and aluminum (Al). In 2002, the amount of TOC and the concentration of soil organic matter (OM) in pasture fields were significantly lower than the concentration in the reference wetland with average values of 7.8 ± 8 g kg-1 and 36 ± 26 g kg-1 and 180.1 ± 188 g kg-1 and 257 ± 168 g kg-1, respectively. It appeared that conversion of wetlands was proceeding toward a soil condition/composition like that of mineral soils. Conclusion and Outlook  Overall, conversion of wetland had significant effects on soil carbon, pH, nitrogen, phosphorus, and extractable nutrients. Results of our study have shown a decrease in TOC, TN, WSP, and K and an increase in soil pH, Ca, Mg, Mn, and Fe. These results are important in establishing useful baseline information on soil properties in pasture and adjoining reference wetland prior to restoring and converting pasture back to its original wetland conditions as a major part of the restoration effort being underway.  相似文献   

13.
Abstract

Soil pH can be increased by manure or compost application because feed rations usually contain calcium carbonate. This study was conducted from 1992 to 1996 to evaluate effects of phosphorus (P) and nitrogen (N)‐based manure and compost application management strategies on soil pH level. Composted and uncomposted beef cattle (Bos taunts) feedlot manure was applied to supply N or P needs of corn (Zea mays L.) for either a one‐ or two‐year period. Phosphorus‐based manure or compost treatments also received additional fertilizer N (ammonium nitrate) to provide for a total of 151‐kg available N ha‐1 yr‐1. Fertilized and unfertilized checks also were included. Manure and composted manure contained about 9 g CaCO3kg‐1 resulting in application rates of up to 1730 kg CaCO3 ha‐1 in 4 years. The surface soil (0–150 mm) pH was significantly decreased with ammonium nitrate application compared to soil in the unfertilized check or to soil receiving manure or compost. Soil pH was significantly increased with the N‐based management strategy compared with the soil original level. In contrast, 4 yr of P‐based manure and compost application strategy maintained soil pH at the original level. Nitrogen‐based applications resulted in higher soil pH than P‐based. Beef cattle feedlot manure and compost can be good sources of CaCO3 for soils requiring lime addition.  相似文献   

14.
15.
针对规模化肉牛场粪污的收集与处理问题,以干清粪工艺为研究对象,总结归纳了规模化肉牛场粪污收集量的计算公式,并以1万头肉牛养殖场为例计算了粪污的产生和收集量,在此基础上选取了堆肥技术处理牛粪,进行了牛粪堆肥处理工艺设计。结果表明:干清粪工艺下规模化肉牛场粪污收集量可由公式直接算出,粪污收集率系数为0.83。养殖规模为1万头的肉牛养殖场,每天的粪尿收集量为150 t,含水率为82%。日处理210 t原料(牛粪150 t+辅料60 t,含水率60%),可产生含水率35%的堆肥产品93.04 t;堆肥项目主要土建工程占地面积为17 738 m2,采用连续动态好氧堆肥处理工艺和配套设备后,实现了整个系统的自动化运行。  相似文献   

16.
南方开放式肉牛舍夏季喷雾降温效果   总被引:1,自引:5,他引:1  
为缓解南方肉牛夏季养殖过程中的热应激,该试验采用喷雾联合悬挂式风机的降温措施对不同品种肉牛的降温效果进行了研究。试验以西门塔尔杂交牛和锦江黄牛为试验品种,测定了环境、直肠温度、呼吸频率和日增质量等评价指标。结果表明:喷雾运行阶段,处理舍空气温度平均可降低2.1℃(P<0.01),相对湿度增加5.8%(P<0.01),降低3.2℃的体感温度(P<0.01);对西门塔尔杂交牛,喷雾结合风机的降温方式可降低其12:00-18:00的平均直肠温度0.3℃和呼吸频率11次/min(P<0.01),有效解除热积聚状况,但对其日增质量无显著提高;对锦江黄牛,喷雾可以降低其呼吸频率14次/min(P<0.01),有效缓解其热应激,日增质量提高0.19kg/d(P<0.05),提高率为27.5%。  相似文献   

17.
Abstract

Nine soil surface treatments and one planting‐hole treatment were tested for their effectiveness in stimulating growth and preventing chlorosis of pin oak (Quercus palustris) seedlings planted in calcareous soil. Planting‐hole acidification was highly effective, especially in combination with a surface treatment of either sulfuric acid or aluminum sulfate. Ammonium sulfate lowered soil pH but was detrimental to the seedlings. Nutrient concentrations in uniformly chlorotic leaves were different from those in interveinally chlorotic leaves, but both types were characterized by low zinc.  相似文献   

18.
Numerous in vitro and in vivo studies have suggested that dietary anthocyanins and ellagitannins or ellagic acid might have beneficial health effects. Epidemiological evidence on the disease-preventing potential of these polyphenols is lacking, due to the absence of reliable data on their contents in foods. In this study was analyzed the content of anthocyanins and ellagitannins (as ellagic acid equivalents after acid hydrolysis) in foods consumed in Finland, including berries, fruits, vegetables, and processed products, using high-performance liquid chromatographic (HPLC) methods. Anthocyanins were detected in 41 of 54 selected food items. The total anthocyanin content varied in berries from 1 to 611 mg/100 g, in fruits from 2 to 66 mg/100 g, and in vegetables from 3 to 75 mg/100 g of fresh weight as the weight of the aglycone. Ellagitannins were screened in 33 food items, but were detected only in 5 species of berries, that is, in cloudberry, raspberry, rose hip, strawberry, and sea buckthorn, the content ranging from 1 to 330 mg/100 g. The results underscore the superiority of berries, especially dark blue or red berries, as excellent sources of anthocyanins and certain berries of the Rosaceae family as the major source of ellagitannins in the Finnish diet.  相似文献   

19.
Aimed at increasing our knowledge on the sensory-active nonvolatiles migrating from oak wood into alcoholic beverages upon cooperaging, an aqueous ethanolic extract prepared from oak wood chips (Quercus alba L.) was screened for its key taste compounds by application of the taste dilution analysis. Purification of the compounds perceived with the highest sensory impacts, followed by liquid chromatography/mass spectrometry as well as one-dimensional and two-dimensional NMR experiments, revealed the ellagitannins vescalagin, castalagin, and grandinin, the roburins A-E, and 33-deoxy-33-carboxyvescalagin as the key molecules imparting an astringent oral sensation. To the best of our knowledge, 33-deoxy-33-carboxyvescalagin has as yet not been reported as a phytochemical in Q. alba L. In addition, the sensory activity of these ellagitannins was determined for the first time on the basis of their human threshold concentrations and dose/response functions. Furthermore, the ellagitannins have been quantitatively determined in extracts prepared from Q. alba L. and Quercus robur L., respectively, as well as in bourbon whiskey and oak-matured red wines, and the sensory contribution of the individual compounds has been evaluated for the first time on the basis of dose/activity considerations.  相似文献   

20.
肉牛甲烷排放影响因素的试验研究   总被引:8,自引:2,他引:8  
为考察不同粗饲料类型、日粮精粗饲料比、能量摄入水平等因素对肉牛甲烷排放量的影响,从而为控制甲烷排放提供理论依据,本研究选用4头18月龄的健康肉用公牛(鲁西黄牛),针对不同粗饲料类型、饲料精粗比和日粮能量摄入水平进行了试验,采用SF6示踪法对甲烷排放量进行了测定。试验结果表明:SF6示踪法可用来快速测定反刍动物的甲烷排放量;影响肉牛甲烷排放量因素的主次顺序依次为:饲料粗料类型>饲料精粗比>能量摄入水平;对肉牛饲喂紫花苜蓿和青贮玉米秸比饲喂稻草和干玉米秸时甲烷排放量要小;日粮中粗饲料越多,则肉牛的甲烷排放量越大;随着能量摄入水平的加大,肉牛的甲烷排放量也呈增加的趋势。  相似文献   

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