分子蒸馏分提生产稻米油技术的研究

以脱胶后的四级稻米油为原料,在脱色的基础上利用分子蒸馏低温高真空二级分提游离脂肪酸,通过单因素和正交试验,优选出了最佳的二级分子蒸馏脱酸工艺条件。结果表明,蒸馏温度180℃,刮膜器转速420 r/min,物料速度40滴/min为最优的一级脱酸条件;蒸馏温度190℃,刮膜器转速420 r/min,物料速度40滴/min为最优的二级脱酸条件。在此条件下,可使油脂的酸值(KOH)小于0.15 mg/g,生产出的稻米油符合国家一级稻米油质量标准。     

基于分子蒸馏技术紫苏油α-亚麻酸纯化效果的研究

为了探究分子蒸馏技术纯化紫苏油α-亚麻酸的可行性,筛选紫苏油提取方法的基础上,考察了蒸馏温度、蒸馏压力、刮板转速和进料速度4个因素对分子蒸馏技术纯化α-亚麻酸效果的影响。结果表明,紫苏油最佳提取法为超临界CO₂萃取法,α-亚麻酸纯化的首要影响因素是蒸馏温度,其次是蒸馏压力,再次是进料速度,最后是刮板转速。最佳纯化工艺：蒸馏温度220℃,蒸馏压力0.07 mbar,刮板转速375 r/min,进料速度1.0 d/min,该工艺条件下α-亚麻酸纯度达到97.42%。该方法有效提高了紫苏油α-亚麻酸的纯度,为高纯度α-亚麻酸的研究和利用奠定了理论基础。     

分子蒸馏技术拆分陈皮挥发油及其GC-MS分析

以陈皮挥发油为研究对象,将其经过分子蒸馏拆分,得到不同馏分物,并分别对陈皮挥发油及所得馏分物进行气相色谱-质谱(GC-MS)分析。分子蒸馏分为二级,一级条件为:蒸发温度(30±0.2)℃,真空度(0.5±0.1)k Pa,刮膜器转速150~160 r/min;二级条件为:蒸发温度(60±0.2)℃,真空度(0.5±0.1)k Pa,刮膜器转速200~210 r/min;两次进样温度25℃,冷凝管温度10℃。结果表明,陈皮挥发油经二级分子蒸馏后总回收率为98.80%,其中一级轻组分(DF1)回收率为40.20%,二级轻组分(DF2)回收率为58.06%,二级重组分(RF2)回收率为0.53%。陈皮挥发油和各馏分物经过GC-MS分析后,确定25种化合物,主要为右旋萜二烯、α-萜品烯、萜品油烯等,但陈皮挥发油及各馏分物成分种类及相对含量差异明显,说明分子蒸馏技术能有效对陈皮挥发油成分进行拆分,可用于陈皮等挥发油的加工利用。     

柚核中柠檬苦素纯化工艺的研究

以乙醇为提取溶剂,采用超声波辅助提取柚核中柠檬苦素,通过正交试验对提取工艺进行优化,并采用大孔吸附树脂纯化柠檬苦素。最佳提取条件为:料液比1∶10,超声时间30min,乙醇体积分数70%,超声提取2次。4020型大孔树脂分离纯化提取液的最佳工艺条件为:吸附流速1mL/min,体积分数70%的乙醇洗脱,解吸流速0.7mL/min,纯化后得到柠檬苦素的质量分数达83.77%。该工艺分离纯化效果好,成本低。     

超临界流体CO_2萃取浙贝母花生物碱的工艺研究

通过单因素试验和正交试验优化,建立了浙贝母花生物碱超临界萃取的工艺参数,确定了最佳萃取工艺条件。结果表明,生物碱超临界萃取的最佳工艺条件为萃取温度70℃,萃取压力35 MPa,萃取时间50 min,夹带剂流速0.15 mL/min,在此条件下总生物碱的理论提取率为3.52±0.15 mg/g。     

响应面法优化分子蒸馏纯化废次烟末中香味成分的研究

以废次烟末为原料,采用分子蒸馏技术对其超临界CO2提取物的香味成分进行分离纯化研究,以纯化物得率和感官品质为评价指标,分别考查了蒸馏压力、蒸馏温度、进料速率对其影响,采用Box-Behnken响应面法对纯化工艺的关键参数进行优化。结果表明,蒸馏温度、蒸馏压力对得率和感官品质的影响显著,得到的最优纯化工艺条件为蒸馏温度61℃,蒸馏压力111 Pa,进料速率11 m L/min,得率为1.54%,感官品质最佳。     

提高大蒜精油得率的酶控工艺研究

大蒜精油具有多方面的药用价值和保健作用,因此已经成为国内外竞相研究的热点课题。该研究从影响蒸馏前蒜氨酸酶活性的酶解条件入手,探究大蒜精油提取率的最佳工艺条件,得出最佳的工艺条件是酶解时间2．5h、酶解温度55℃、pH值6．6、蒸馏时间45min、蒸馏电压120V。实验结果表明,良好的酶控条件可以大大提高大蒜精油的产出率,最高可达0．57％。     

黄花菜多酚提取工艺及抗氧化作用的研究

探讨黄花菜多酚最佳提取工艺及抗氧化作用。结果表明,黄花菜多酚最佳提取工艺为:提取时间60min、乙醇浓度55%、料液比1∶15、提取温度35℃;在此条件下,多酚得率为28.89%。抗氧化试验表明黄花菜多酚对羟自由基、超氧阴离子自由基、DPPH自由基均具有一定的清除作用,其半抑制率(IC50)分别为0.1176mg/mL、0.1638mg/mL和0.1593mg/mL,且清除率与黄花菜多酚浓度成量效关系。     

柚皮柠檬苦素的提取及其杀虫活性研究

为了探究柚皮中柠檬苦素的最佳提取工艺及其杀虫活性,采用正交试验对柚皮中柠檬苦素的提取工艺进行优化,利用得到的柠檬苦素对夹竹桃蚜虫、吹绵蚧和菜蝽喷雾进行杀虫试验。结果表明：超声波提取法、二氯甲烷和丙酮水浴提取法从10 g柚皮中提取到的柠檬苦素分别是0.9700、1.5860、1.6000 g;二氯甲烷水浴提取法对柚皮中的柠檬苦素提取率为6.08%。10 mg/mL的柠檬苦素能将供试害虫全部杀死,0.625 mg/mL的柠檬苦素依然有较高的杀虫活性。回流法提取柚子皮中的柠檬苦素时,最佳提取工艺是：二氯甲烷为提取溶剂,液料比为1:12,回流提取2次,每次2 h,温度50℃;得到的柠檬苦素对3种供试害虫有较强的杀虫活性。     

超声波辅助提取沙田柚种籽油工艺优化研究

为了优化超声波提取沙田柚种籽油的工艺参数。在单因素试验基础上,通过采用响应面法,对超声波辅助时间、液料比、超声波功率比和温度进行了优化。结果表明,最佳工艺参数为：提取溶剂为异丙醇、时间为40 min、超声波功率比为73.77%、液料比为5.9:1(mL/g)、提取温度为47.39℃。在此最佳工艺参数下,沙田柚种籽油的提取率达38.82%。     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Genetic constitution and diversity in four narrow endemic redwoods from the family Cupressaceae

The genetic constitution and diversity of four relictual redwoods are discussed in this review. These include monotypic genera of the family Cupressaceae: coast redwood (Sequoia sempervirens), giant sequoia (Sequoiadendron giganteum), dawn redwood (Metasequoia glyptostroboides), and alerce (Fitzroya cupressoides). All four species are narrow endemics, share a number of common phenotypic traits, including red wood, and are threatened species. Fossil history suggests that the ancestors of redwoods probably originated during the Cretaceous and Tertiary periods and flourished thereafter for millions of years. Towards the end of the Tertiary period began their decline and struggle for existence that continued during the subsequent geologic upheavals and climate changes, until the survival of the present-day redwoods in the current restricted locations in the world (USA, China, and South America). Although two species, Sequoiadendron and Metasequoia, are diploids (2n = 22), and the other two are polyploids: Fitzroya a tetraploid (2n = 4x = 44), and Sequoia a hexaploid (2n = 6x = 66); they all share the same basic chromosome number x = 11. The genome size in the hexaploid Sequoia is one of the largest (31,500 MB) in the conifers, while the genome sizes of diploid Metasequoia and Sequoiadendron are about one-third (~10,000 MB) of Sequoia. Genetic diversity in the redwoods is lower than most other gymnosperms, except in Sequoia, which seems to rank near the upper quarter of the coniferous forest trees. Genomic research is sparse in the redwoods, and should be pursued for a better understanding of their genome structure, function, and adaptive genetic diversity.     

Distribution,ecology and reproductive biology of wild tomatoes and related nightshades from the Atacama Desert region of northern Chile

Over the past 20 years, several expeditions were made to northern Chile to collect populations of wild tomatoes (Solanum chilense, S. peruvianum) and allied nightshades (S. lycopersicoides, S. sitiens), and obtain information about their geographic distribution, ecology and reproductive biology. Restricted mainly to drainages of the Andean and the coastal cordillera, populations are geographically fragmented. The two nightshade species are rare and threatened by human activities. Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.     

The induction in vitro of adventitious shoots in Rosa

Summary Adventitious shoots were formed on excised leaves, roots and callus of Rosa persica x xanthina and on excised leaves of R. laevigata and R. wichuraiana on culture media that included BAP and NAA as growth regulators. Shoots formed freely on freshly cultured callus of R. persica x xanthina but their production declined in successive cultures and ceased after twelve weeks. Transplantation to soil was improved by rooting plantlets in cellulose plugs in vitro and transferring plantlets to soil while still in the plugs.     

The exploration of genetic resources of Portuguese cabbage and kale for resistance to several Brassica diseases

Summary Twenty three accessions of nine Portuguese cabbage and kale land races from different geographic origins were tested at the seedling stage for resistance to several important brassica diseases. Resistance to downy mildew (Peronospora parasitica), expressed as necrosis of the cotyledon mesophyll, was found in all the accessions. Type A resistance to cabbage yellows (Fusarium oxysporum f. sp. conglutinans race 1) was present in most of the landraces. Resistance to clubroot (Plasmodiophora brassicae race 6) was found in one accession of the Portuguese tree kale. High resistance to blackleg (Leptosphaeria maculans) and white rust (Albuco candida) was not detected, although several accessions showed 20 to 30% of plants with intermediate expression of resistance. All Portuguese cole accessions were susceptible to blackrot (Xanthomonas campestris pv. campestris).     

Production and characterization of intergeneric diploid cybrids derived from symmetric fusion between Microcitrus papuana Swingle and sour orange (Citrus aurantium)

Plants were regenerated from intergeneric somatic hybridization between embryogenic protoplasts of Microcitrus papuana Swingle and leaf-derived protoplasts of sour orange (Citrus aurantium L.) via electrofusion. The regenerated plants were morphologically similar to the leaf parent in growth vigor, leaf and branch structure. FCM analysis showed that they were diploids. Simple-sequence-repeat (SSR) and cleaved-amplified-polymorphic-sequence(CAPS) were employed for hybridity characterization. SSR banding patterns of the regenerated plants were identical to the leaf parent, sour orange, indicating that they possessed nuclear component derived from sour orange. DNA amplification with chloroplast and mitochondrial universal primers, followed by restriction endonuclease digestion, revealed polymorphism between the fusion parents. Therefore, this method was used to determine the cytoplasmic compositions of the regenerated plants. Banding patterns for all the polymorphic primer/enzyme combinations of the regenerated plants were similar to those of the embryogenic parent, M. papuana, suggesting that only the cytoplasmic components derived from the embryogenic parent were present in the regenerated plants. FCM, SSR and CAPS demonstrated that intergeneric diploid cybrids have been successfully obtained by symmetric fusion. Related results concerning nuclear and cytoplasmic composition of previous diploid somatic hybrids and potential mechanism for regeneration of such kind of plants are discussed herein. This revised version was published online in July 2006 with corrections to the Cover Date.