Some Volatile Plant Compounds in Halloumi Cheeses made from Ovine or Bovine Milk

The volatile flavour componds in commercial samples of fresh Halloumi cheese made from either bovine milk or a mixture of ovine and caprine milks were compared. Terpenes, such as α-pinene, β-pinene, copaene, thymol, α-caryophyllene, β-caryophyllene and δ-cadinene were all present in the ovine/caprine cheeses and, in some cases, at concentrations above their reported flavour threshold values. Only low levels of α-pinene and β-caryophyllene were found in the bovine samples, along with D -carvone and eucalyptol from mint added during manufacture. Analysis of some plants that dominated the feeds of the sheep/goats or cows that produced the original milk indicated that the terpenes are likely to have originated in the plants eaten by the animals. It was suggested that the presence of the terpenes may explain the preference of some consumers for the fresh ovine/caprine cheese.     

Chemicals and polymers from biomass

While fossil energy prices remain relatively low and agricultural prices are maintained at a relatively high level as a result of production costs, the use of purpose grown crops as a source of fuels requires subsidies, tax support or other financial incentives to be viable. In the short term, the use of agricultural and forest raw materials as industrial raw materials for production of higher value products appears more attractive. However, simple substitution of a petroleum-based product by one derived from plants is seldom possible. Options are reviewed, covering both established commercial activities (such as starch, vegetable oil, paper-pulp and natural fibres), as well as the extensive research and development activities that should lead to new crops, new products and new markets.     

Diseases and pests in energy crop plantations

The Pest and Disease Management Activity was established in response to an awareness of the potential importance of pests and diseases in woody biomass production systems. Annual surveys in Canada, Eire, England, N. Ireland, Scotland and Sweden from 1987–1991 confirmed that rust disease (Melampsora spp.) is currently the most serious problem in willow biomass production in Europe. Other pests and diseases cause problems only on a local scale, though they could become more generally severe. Increasing clonal susceptibility to rust and an an increasing association of premature defoliation with lower rust severity levels have occurred over the period. A high degree of intrinsic variability in pathogen populations is expressed as four formae speciales (f.spp.) and at least eight pathotypes of the most common rust species, M. epitea. The same f.spp. appear to occur among pathotypes in Sweden, New Zealand and the UK. A network of field experiments has been established, in collaboration with the Joint Trials Activity, to enable the rust pathotype composition to be compared between five countries. It also aims to identify an international set of standard willow clones to be utilized for characterizing rust pathotypes globally.     

地质统计学在作物需水量研究中的应用

地质统计学是在G.马特隆的区域化变量理论基础上形成并发展起来的一门新兴学科。本文应用地质统计学分析研究了作物需水量的空间变异及最优估计问题。     

农业温室慎用臭氧

平流层臭氧有益，近地面臭氧是重要空气污染物。臭氧是氧化剂，可用于杀菌和消毒。臭氧也污染环境，既危害健康，也危害植物。臭氧造成农作物减产。对于生长期的温室作物，用臭氧对付病虫害的做法不可取.     

Antioxidant capacity of extracts from wild and crop plants of the Mediterranean region

ABSTRACT:  There is an increasing demand for natural antioxidants to replace synthetic additives in the food industry. The present work examines the potential of some wild and cultivated plants from the Mediterranean region as sources of natural antioxidants. Samples of different organs and tissues from each of these species were extracted with aqueous and organic solvents and analyzed for their total hydrosoluble and lipid-soluble antioxidant capacity, measured by the phosphomolybdenum method, and for their content in tocopherols. Our results demonstrate that there is more than a 1000-fold difference among total antioxidants in various plant sources. The highest level of water-soluble antioxidant capacity was found in fruit peel and leaf samples, while seeds presented the highest levels of lipid-soluble antioxidant capacity. Tocopherols were more abundant in leaf samples. Holm oak and olive tree leaves showed the highest yields of α-tocopherol. These Mediterranean plant species could be used as a very good source of both water-soluble and lipid-soluble antioxidants, particularly α-tocopherol.     

Soil carbon sequestration beneath hybrid poplar plantations in the North Central United States

Hybrid poplar plantations grown on tilled agricultural lands previously in prairie, sequester significant quantities of soil carbon. Comparisons are made between hybrid poplar plantations and adjacent row crops or mowed grass. Establishing and tending plantations often results in early soil carbon loss, but soil carbon is significantly related (positive) to tree age. Increasing tree age eventually results in a net addition of soil carbon from plantations older than about 6 to 12 years of age. Soil carbon loss under trees occurred most frequently from the surface 30 cm early in the plantation history—evidence that the loss was due to mineralization. Soil carbon gain was most significant in the 30–50 cm layer and was attributed to tree root growth. Soil carbon accretion rate beneath 12- to 18-year-old poplar plantations exceeded that of adjacent agricultural crops by l.63 ± 0.16 Mg ha⁻¹ yr⁻¹. There was a significant crop × soil depth interaction for bulk density with bulk density lower beneath trees in the 0–30 cm layer and higher in the 30–50 cm layer. There was little evidence of carbon trapping of wind-blown organic detritus by tree plantations in the prairie environment.     

基于MODIS数据的大尺度作物遥感监测综述

我国幅员辽阔,作物种类丰富,如何及时、客观、准确地收集我国作物信息,对科学指导农业发展具有重要的意义.本文以MODIS数据为主要信息源,以农作物的波谱特性和生物学特性机理为基础,开展利用MODIS数据的高光谱多时相及免费获取的优势,进行大尺度农情遥感监测研究,发展了适用的模型和算法,实现大尺度主要作物类型信息的遥感提取和产量遥感估算,提高了农作物遥感定量精度,并探讨了基于MODIS数据的全球农作物遥感监测的现状.同时,针对大尺度农情遥感监测中涉及的农业气候环境网格信息系统做了初步尝试.     

我国生物质能源现代化应用前景展望(一)——生物质资源和供给

生物质能除了可以在改善世界一次能源结构、降低化石能源需求量方面做出重要贡献以外,还可在减少温室气体排放、保障能源供应安全、改善贸易平衡、促进农村发展和改进城市废弃物处理方式等方面发挥作用。目前全球每年一次能源消费总量为500EJ,生物质资源的年用量约占一次能源消费总量的10%左右,主要被用于传统的民用燃料和生产第一代生物燃料。第二代生物燃料技术预计将于2020年前后在一些国家实现工业化生产。IEA预测,2050年世界一次能源需求量为670EJ,生物质资源将占一次能源需求总量的20%左右。各方学者预测的2050年全球生物质资源量最低值基本在200~400EJ之间,最高值在400~1500EJ之间。中国的生物燃料产业尚处于起步阶段,不过应该说取得了良好的开端。我国生物质资源相对较少,且分布不均,发展生物质能产品需要依靠能源作物。只有通过合理开发、有效利用,才能在不与粮食和食用油争夺土地的前提下,在一定程度上提供生物运输燃料和生物质发电供热所需的原料,生物质能-农产品和/或生物质能-林产品联合生产系统应成为主要发展方向。美国生物燃料产业的发展模式对我国具有一定的借鉴意义。生物质最有效的利用方式是生产运输燃料,从长远来看,生物燃料可以与石油燃料竞争,尤其是喷气燃料和汽油更具替代优势,但受到生物质资源供应量的制约。     

粮油中可开发的功能性成分

近年来,功能性食品成为世界食品工业新的增长点,为功能性食品配套的作为添加剂和配料的功能性成分也成为国内外竞相研究和开发的热点。水稻、小麦、玉米、大豆、花生、芝麻及红薯等为我国主要的粮油作物,这些粮油作物含有丰富的对人体健康有益的功能活性成分。本文对这些粮油作物中可供开发的功能性成分进行了简要综述,为粮油作物中功能性添加剂及配料的开发提供参考,进而促进粮油资源价值的充分发掘。