超临界CO2萃取琉璃苣芳香油参数的优化

采用超临界CO2萃取技术,利用正交设计对琉璃苣(Borago officinlis)芳香油萃取参数进行了优化研究.结果表明,影响超临界CO2萃取量最重要因子为萃取压力,其次是萃取温度;最佳萃取工艺参数组合为萃取压力20 MPa、萃取温度35℃、萃取时间2.0 h、CO2流量3.0 L/h.采用该参数组合进行超临界CO2萃取,琉璃苣芳香油含量高达0.684％.     

环氧乙烷熏蒸小麦矮腥黑粉菌应用技术的研究

应用环氧乙烷熏蒸进口小麦矮腥黑粉菌取代干热灭菌法获得成功,为进口小麦灭菌处理开辟了新的途径。试验表明环氧乙烷熏蒸小麦矮腥黑粉菌的有效剂量为175—200克/米~3,熏蒸期间粮温15—25℃,密闭熏蒸3—5天。同时还对矮腥黑粉菌有一定的持续效果。每立方米用150—200克的环氧乙烷熏蒸小麦,对种子的生活力有影响,不宜用于少量引种繁殖材料的熏蒸,只能作进口小麦灭菌处理。     

猪瘟病毒EO基因在CHO细胞中的表达

将EGFPEO融合基因插入哺乳动物细胞表达载体pCI-dhfr中,构建重组质粒pCI-EGFPE0.将重组质粒转染CHO(dhfr'),在荧光显微镜下观察到少数细胞呈现绿色荧光,表明转染成功.通过MTX加压筛选后,在荧光显微镜下观察到多数细胞呈现强绿色荧光,表明重组融合蛋白EGFPE0在CHO细胞中得到大量表达.高效表达重组融合蛋白细胞克隆的获得为进一步大量制备可溶性的猪瘟病毒E0糖蛋白、制备其单抗筛选抗原表位及研究E0蛋白的生物学功能奠定基础.     

猪多杀性巴氏杆菌病活疫苗（EO630株）生产用合成培养基的研究

为便于猪多杀性巴氏杆菌病活疫苗（E0630株）质量控制和降低生产成本,研制了ZJ-1和ZJ-2两种合成培养基,并进行了两种合成培养基与马丁肉汤的比较试验。结果表明,合成培养基ZJ-1培养活菌数高于ZJ-2和马丁肉汤。用合成培养基ZJ-1培养制备3批疫苗,并分别用兔进行安全检验和小鼠效力检验。3批疫苗对兔均2／2健活,对小鼠的保护力分别为9／10、9110、8／10,符合产品质量标准。本试验表明,运用合成培养基替代传统培养基是可行的。     

Effect of electrolyzed oxidizing water and continuous ozone exposure on the control of Penicillium digitatum on tangerine cv. ‘Sai Nam Pung’ during storage

The effect of electrolyzed oxidizing (EO) water in combination with ozone to control postharvest decay of tangerine cv. “Sai Num Pung” was investigated. The spore suspension containing 10⁵ conidia ml⁻¹ of Penicillium digitatum was prepared. EO water was generated by electrolysis of various concentrations of NaCl solution (5, 25, 50% and saturated NaCl). The spore suspension was inoculated into EO water and incubated at 27 °C for 1, 2, 4, 8 and 32 min. It was found that the EO water with saturated NaCl completely inhibited the spore germination of the fungus within 1 min. When the fruits inoculated with P. digitatum were washed in EO water at the same concentrations as previous experiment for 4, 8 and 16 min and stored at 5 °C for 18 days, it was found that immersion of the fruit in EO water for 8 min was the most effective to reduce disease incidences. Moreover, washing fruit in EO water and kept in a refrigerated chamber at 5 °C with continuous ozone exposure at a concentration of 200 mg l⁻¹ for 2 h day⁻¹ to extend storage life suppressed the disease incidence until 28 days. However, none of the treatments had any effect on the quality of fruit such as total soluble solids, titratable acidity, percent weight loss and peel color. Therefore EO water may be useful for surface sanitation and ozone has potential to control the recontamination of postharvest diseases in tangerine fruit in storage room.     

黑龙江农田土壤壬基酚及其短链聚氧乙烯醚残留调查

对黑龙江土壤样品中的壬基酚(NP)、壬基酚一氧乙烯醚(NP1EO)和壬基酚二氧乙烯醚(NP2EO)的残留状况开展研究。结果表明,NP、NP1EO和NP2EO均有不同程度的检出,检出率在68.46%~95.38%之间;NP、NP1EO和NP2EO的浓度分别为ND~156.8μg kg-1、ND~15.70μg kg-1和ND~13.63μg kg-1,均值分别为22.02μg kg-1、4.04μg kg-1和2.15μg kg-1;进一步分析,已检出的样品中,NP在0~10μg kg-1的比重最大,NP1EO在4~6μg kg-1比重最大,NP2EO在1~2μg kg-1比重最大。NP的残留水平高于NP1EO和NP2EO,说明NP相对较难降解,更易在土壤中累积。     

Characterization of Slightly and Moderately Saline and Sodic Soils in Irrigated Agricultural Land using Simulated Data of Advanced Land Imaging (EO‐1) Sensor

Around the world, especially in semi‐arid regions, millions of hectares of irrigated agricultural land are abandoned each year because of the adverse effects of irrigation, mainly secondary salinity and sodicity. Accurate information about the extent, magnitude, and spatial distribution of salinity and sodicity will help create sustainable development of agricultural resources. In Morocco, south of the Mediterranean region, the growth of the vegetation and potential yield are limited by the joint influence of high temperatures and water deficit. Consequently, the overuse of surface and groundwater, coupled with agricultural intensification, generates secondary soils salinity and sodicity. This research focuses on the potential and limits of the advance land imaging (EO‐1 ALI) sensor spectral bands for the discrimination of slight and moderate soil salinity and sodicity in the Tadla's irrigated agricultural perimeter, Morocco. To detect affected soils, empirical relationships (second‐order regression analysis) were calculated between the electrical conductivity (EC) and different spectral salinity indices. To achieve our goal, spectroradiometric measurements (350 to 2500 nm), field observation, and laboratory analysis (EC of a solution extracted from a water‐saturated soil), and soil reaction (pH) were used. The spectroradiometric data were acquired using the ASD (analytical spectral device) above 28 bare soil samples with various degrees of soil salinity and sodicity, as well as unaffected soils. All of the spectroradiometric data were resampled and convolved in the solar‐reflective spectral bands of EO‐1 ALI sensor. The results show that the SWIR region is a good indicator of and is more sensitive to different degrees of slight and moderate soil salinity and sodicity. In general, relatively high salinity soils show higher spectral signatures than do sodic soils and unaffected soils. Also, strongly sodic soils present higher spectral responses than moderately sodic soils. However, in spite of the improvement of EO‐1 ALI spectral bands by comparison to Landsat‐ETM+, this research shows the weakness of multispectral systems for the discrimination of slight and moderate soil salinity and sodicity. Although remote sensing offers good potential for mapping strongly saline soils (dry surface crust), slight and moderately saline and sodic soils are not easily identified, because the optical properties of the soil surfaces (color, brightness, roughness, etc.) could mask the salinity and sodicity effects. Consequently, their spatial distribution will probably be underestimated. According to the laboratory results, the proposed Soils Salinity and Sodicity Indices (SSSI) using EO‐1 ALI 9 and 10 spectral bands offers the most significant correlation (52.91%) with the ground reference (EC). They could help to predict different spatial distribution classes of slight and moderate saline and sodic soils using EO‐1 ALI imagery data.     

Molecular response of Musca domestica L. to Mintostachys verticillata essential oil, (4R)+-pulegone and menthone

Intense applications of synthetic insecticides for the control of adult Musca domestica have led to the insects developing resistance to most of them. In consequence, there is interest in new active ingredients as alternatives to conventional insecticides. Essential oils (EO) are potential tools for controlling M. domestica because of their effectiveness and their minimal environmental effects. In a fumigant assay, M. domestica adults treated with Minthostachys verticillata EO [LC(50)=0.5 mg/dm(3); majority components by SPME-GC: (4R)(+)-pulegone (67.5%), menthone (22.3%) and (4R)(+)-limonene (3.8%)], died within 15 min or less. The terpenes absorbed by the flies and their metabolites, analyzed using SPME fiber, were (4R)(+)-limonene (LC(50)=6.2 mg/dm(3)), menthone (LC(50)=1.9 mg/dm(3)), (4R)(+)-pulegone (LC(50)=1.7 mg/dm(3)) and a new component, menthofuran (LC(50)=0.3 mg/dm(3)), in a relative proportion of 12.4, 6.5, 35.9 and 44.2% respectively. Menthofuran was formed by oxidation of either (4R)(+)-pulegone or menthone mediated by cytochrome P450, as demonstrated by a fumigation assay on flies previously treated with piperonyl butoxide, a P450 inhibitor, which showed a decrease in toxicity of the EO, (4R)(+)-pulegone and of menthone, supporting the participation of the P450 oxidizing system in the formation of menthofuran. The enzymatic reaction of isolated fly microsomes with the EO or the (4R)(+)-pulegone produced menthofuran in both cases. Contrary to expectations, the insect detoxification system contributed to enhance the toxicity of the M. verticillata EO. Consequently, resistant strains overexpressing P450 genes will be more susceptible to either M. verticillata EO or (4R)(+)-pulegone and menthone.     

Comparative Evaluation of Natural Antioxidant Coating and Vacuum-Packaging Technique on Quality Characteristics of Chill Stored Giant Trevally Fillets

ABSTRACT

The effect of coating with natural antioxidants like sage and oregano essential oils (EO), and tocopherol on spoilage characteristics of giant trevally fillets was evaluated during chilled storage. Further, results were compared against vacuum and conventional polyethylene packaging practices. Prior to coating, the properties of antioxidants were evaluated in vitro using standard activity assays. Coating with EO was found effective in retarding lipid oxidation in fish fillets; while tocopherol accelerated the spoilage process. It was concluded that EO treatment can slow down the process of spoilage in fish fillets and can be considered as an alternative to expensive vacuum-packaging technique.