改性蒙脱石对黄曲霉毒素B_1和玉米赤霉烯酮的吸附研究

本试验旨在探究4种不同改性蒙脱石对黄曲霉B1(AFB1)和玉米赤霉烯酮(ZEN)的体外吸附性能。采用体外吸附试验,在霉菌毒素污染的喷浆玉米皮中添加4种改性蒙脱石,检测AFB1和ZEN的浓度变化,以探究不同种类及不同添加比例改性蒙脱石对AFB1和ZEN的吸附作用。结果表明:4种改性蒙脱石对AFB1和ZEN均有显著吸附作用,其中膨润土经十八烷基三甲基氯化铵改性制备的复合改性蒙脱石II型对AFB1和ZEN的吸附效果最好,在添加量为1%时,对AFB1和ZEN的吸附率分别为62.60%和43.38%。在本体外试验条件下,4种改性蒙脱石对喷浆玉米皮中AFB1和ZEN均具有吸附作用,可以降低喷浆玉米皮中的霉菌毒素含量,为改性蒙脱石在饲料脱毒剂的使用提供参考。     

Rainfall erosivity and erosivity density through rainfall synthetic series for São Paulo State,Brazil: Assessment,regionalization and modeling

Rainfall is the main cause of erosion of Brazilian soils, which makes assessing the rainfall erosivity factor (RE) and the erosivity density (ED) fundamental for soil and water conservation. Therefore, the objectives of this study were: i) to estimate the RE and ED for São Paulo State, Brazil, using synthetic series of pluviographic data; ii) to define homogeneous regions regarding rainfall erosivity; and iii) to generate regression models for rainfall erosivity estimates in each of the homogeneous regions. Synthetic series of pluviographic data were initially obtained on a sub-daily scale from the daily rainfall records of 696 rainfall gauges. The RE values were then estimated from the synthetic rainfall data, and ED was calculated from the relationship between erosivity and rainfall amounts. Monthly and annual maps for RE and ED were obtained. Hierarchical clustering analysis was used to define homogeneous regions in terms of rainfall erosivity, and regionalized regression models for estimating RE were generated. The results demonstrate high spatial variability of RE in São Paulo, where the highest annual values were observed in the coastal region. December to March concentrate approximately 60% of the intra-annual erosivity. The highest values of annual ED were observed in regions with intense agricultural activity. The definition of five homogeneous regions concerning the rainfall erosive potential evidenced distinct seasonal patterns of the spatial distribution of erosivity. Finally, the high predictive accuracy of the regionalized models obtained characterizes them as essential tools for reliable estimates of rainfall erosivity, and contribute to better soil conservation planning.     

Amino acid profile of the quinoa (Chenopodium quinoa Willd.) using near infrared spectroscopy and chemometric techniques

The high content of amino acids of the quinoa, especially essential amino acids (higher than other cereals) makes a food increasingly demanded by consumers. A total of twelve amino acids (arginine, cystine, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine) were analyzed in quinoa samples from Chile by near infrared spectroscopy (NIR) with direct application to the samples of a remote fiber-optic reflectance probe. The calibration results using modified partial least squares (MPLS) regression satisfactorily allowed the determination of the concentrations of this amino acid group with high multiple correlation coefficients (RSQ = 0.97–0.71) and low standard prediction errors (SEPC = 0.07–0.20). The prediction capacity (RPD) for the arginine, the cystine, the isoleucine, the lysine, the serine, the threonine, the tryptophan, the tyrosine and the valine ranged between 2.6 and 5.2, for the rest of amino acids were higher to 1.8, indicating that the NIRS equations obtained were applicable to unknown samples. It has confirmed that NIRS technology is a method that may be useful to replace the traditional methods for routine analysis of some amino acids.     

茧壳水煎剂对四氧嘧啶糖尿病模型小鼠的降血糖作用

用不同剂量的茧壳水煎剂分别对正常小鼠和四氧嘧啶糖尿病模型小鼠进行了降血糖作用研究。结果显示 :干茧壳剂量为 1 6、3 2g/kg·d的茧壳水煎剂对正常小鼠连续灌胃 2 0d ,其血糖水平没有明显变化 ;用干茧壳剂量为 1 6g/kg·d的茧壳水煎剂对四氧嘧啶糖尿病模型小鼠连续灌胃 2 0d ,或用干茧壳剂量为 3 2g/kg·d的茧壳水煎剂对四氧嘧啶糖尿病模型小鼠连续灌胃 10d ,其血糖没有显著降低 ;而干茧壳剂量为 3 2g/kg·d的茧壳水煎剂对四氧嘧啶糖尿病模型小鼠连续灌胃 14、2 0d ,有显著的降血糖作用 ,但是若不继续灌胃给药 ,则 7d后 ,这种降血糖作用又丧失。该研究结果为利用蚕茧治疗糖尿病提供了药理学方面的依据     

加味当归四逆壳聚糖喷膜剂的研制

研制加味当归四逆壳聚糖喷膜剂,并且制定生产工艺和质量标准。试验采用水煎法提取处方药材;通过正交试验确定壳聚糖盐酸盐、PVPK-30以及乙醇成膜材料的最佳配比;按照药典相关规定,采用紫外分光光度法测定每瓶总黄酮的含量。成膜材料的最佳配比为壳聚糖盐酸盐1%,3%PVPK-30和40%乙醇。通过TLC鉴定样品含有阿魏酸和芍药苷成分。质量标准中性状为澄清有清凉气味的红棕色液体,总黄酮的含量1.83 mg/mL。以处方为219 mg/mL中药复方,1%的壳聚糖盐酸盐,3%的PVPK-30以及40%的乙醇制备出加味当归四逆壳聚糖喷膜剂,且制定质量标准中样品含有阿魏酸和芍药苷并且每瓶总黄酮含量满足1.83 mg/mL。     

响应面法优化当归补血汤液体发酵工艺

为确定当归补血汤液体发酵的最佳工艺,本试验采用枯草芽孢杆菌为发酵菌种,以多糖提取率为评价指标进行液体发酵工艺优化。首先采用单因素试验考察发酵培养基中葡萄糖和蛋白胨添加量、菌液接种量和发酵时间对多糖提取率的影响,再以此为基础,采用Box-Behnken中心组合试验设计法,选取葡萄糖添加量、蛋白胨添加量、接种量、发酵时间为发酵优化的4个因素,以多糖提取率为响应值,设计4因素3水平的试验方案并进行响应面分析,以确定各因素与响应值多糖提取率的关系。结果显示,各因素对多糖提取率变化的贡献大小依次为葡萄糖添加量、蛋白胨添加量、接种量、发酵时间;利用响应面分析结果显示,蛋白胨添加量与接种量和发酵时间、接种量和发酵时间的交互作用较为显著,最终确定最佳发酵工艺条件为：葡萄糖添加量0.95%,蛋白胨添加量1.52%,接种量2.92%,发酵时间35.8 h。该条件下多糖提取率达到9.23%,与未发酵组（4.62%）相比,多糖含量提高近2倍。该工艺对液体发酵当归补血汤产多糖优化效果显著,为发酵当归补血汤的进一步开发利用提供了理论基础。     

蘑菇保鲜技术及其生理效应

试验比较了~(60)Co—r 射线辐照、气调、药剂等保鲜方法对双孢蘑菇保鲜的效果,得出以纸塑袋密封包装,加天然去异味剂,采用自发气调法保鲜,效果最佳。在5℃左右温度条件下可以保存10—15天,开伞率不超过3%,基本无褐变和异味,失重率在2%以内,质地基本不下降。同时,研究了自发气调保鲜的作用机制,证明自发气调保鲜法,氧与二氧化碳分压可分剐调整到2—3%和10—15%,在这种条件下,多酚氧化酶的活性明显下降。     

Agar/galactomannan blends for strawberry (Fragaria x ananassa Duchesne) cv. Pelican micropropagation

The efficacy of partial substitution of agar by galactomannans (GMs) obtained from different sources was tested in strawberry (Fragaria x ananassa Duchesne) cv. Pelican micropropagation. GMs extracted from seeds of Cassia fastuosa (cassia) and Cyamopsis tetragonolobus (guar gum – a commercial GM) were mixed with agar in the proportion of 0.3/0.3% (w/v) in MS medium, and the performance was compared with behaviour of medium containing agar only (0.6%, w/v) as gelling agent. The results obtained showed that agar could be partially replaced by GMs, since the rheological measurements confirmed a good interaction between the polysaccharides. Also, better performance and enhanced proliferation of strawberry shoots were observed; where in the modified medium the length of roots was higher. Thus, the behaviour of the agar/galactomannans gels and the commercial cost effectiveness, which is lower for the modified medium compared with the system solidified with agar only, showed the potential use of these galactomannans for application in plant tissue culture.     

甘蓝型低芥酸油菜单株产量基因效应的研究

用5×5半双列杂交研究甘蓝型低芥酸油菜单株产量的遗传,结果表明:供试的甘蓝型低芥酸油菜品系中,单株产量的遗传符合加性显性模型,显性性质为超显性,平均显性度为1.404。显性基因约为隐性基因的3倍多,并且多数增效基因表现显性,但也有显性的减效基因存在。单株产量的广义遗传力h_B~2=71.4％,狭义遗传力h_N~2=33.18％。供试亲本显性效应的强弱依次为81007>81006>81018>81004>81033,增效基因的多少依次为81018>81006>81007>81004>81033。一般配合力的大小依次为81018>81006>81004>81033>81007。     

多品种（系）试验中简化广义格子设计的探讨

根据多品种（系）田间试验的特点，在Ｐａｔｔｅｒｓｏｎ等广义格子设计基础上提出简化广义格子设计（简称ＳＧＬ设计）。ＳＧＬ设计基于格子设计的正交性原理，对于可用区组容量整除的任何供试品种数、２－４次重复，均可构成不完全区组设计。且构成方法简便，设计效率因子高，具有可解析性，连通性，ＳＧＬ设计的参数采用修饰极大似然法估计。