二氧化碳膨胀处理对烟丝物理结构的影响

将34种单等级烟叶通过二氧化碳膨胀制成膨胀烟丝,测量膨胀前后烟丝的整丝率、碎丝率和填充值,研究膨胀前后烟丝各物理结构指标的变化规律,并比较等级、部位等因素对于膨胀烟丝物理结构的影响。结果表明,烟丝膨胀后,整丝率显著性下降,填充值显著性上升,碎丝率变化不显著。不同等次和部位的烟丝膨胀前后结构指标变化存在一定差异,下等烟、下部烟和上部烟的整丝率显著下降,碎丝率增加较多,而中部烟和中上等烟整丝率保持较好,碎丝增加较少。     

香菇多糖的超滤分离及保润性能研究

采用溶剂提取法从香菇中提取香菇多糖,通过酶解法和Seveg法除去多糖中的蛋白质,得到香菇精多糖。通过超滤分离手段将香菇多糖按照分子量的大小分成4个组分,LE1、LE2、LE3和LE4。将4种香菇多糖以不同重量比添加到烟丝中,分别测量其在30%和80%湿度下的平衡含水率,表征其物理保润性能。结果表明,添加香菇多糖能明显提升烟丝在干燥环境下的平衡含水率,并降低潮湿环境下的平衡含水率。随着香菇多糖分子量的增加,其在潮湿环境下的防潮性能不断提升,而干燥环境下的保湿性能先增加后降低。     

西藏地区草莓"章姬"和"红颜"茎尖快繁技术研究

以草莓品种"红颜"和"章姬"匍匐茎茎尖为材料,研究外植体诱导、试管苗增殖与生根培养过程中外源激素种类与浓度配比及试管苗驯化移栽条件,为高原低气压地区设施草莓脱毒种苗生产提供理论依据.结果 表明:初代培养中,随6-BA浓度增加,草莓茎尖不定芽萌发率先升后降,MS+6-BA1.5处理表现最好;与只添加6-BA相比,增加一定量的NAA能显著提高草莓不定芽萌发率,MS+6-BA1.0+NAA0.2组合优势最强,"红颜"和"章姬"不定芽萌发率分别达62％和75％.和初代培养相比,继代与增殖培养中,需要较低浓度配比的外源激素,MS+6-BA0.2+NAA0.1组合优势最强,"红颜"和"章姬"丛生芽增殖系数分别达4.2和4.8.加入一定量的IBA,可促进草莓试管苗发根,以1/2 MS+IBA0.05处理最有效,"红颜"和"章姬"发根率分别达78.4％和88.1％.驯化移栽过程中,草炭∶蛭石∶珍珠岩=4∶1∶1基质组合相对较好,两供试草莓试管苗成活率分别达50.1％和47.9％.6-BA在草莓茎尖快繁体系中起着主导性作用,NAA可协同促进这一作用.     

基于离散多带小波变换的种蛋性别鉴别

蛋类生产中,母鸡的生产效益远高于公鸡,而在肉鸡生产中,公鸡又比母鸡饲料利用率高,生长速度快,生命力强[1].因而性别识别成为提高养鸡生产效益的一种重要技术途径.为更好地调控公、母养殖比例,满足不同时期的市场需要,节约种苗生产成本,急需寻求"种蛋性别鉴定技术".     

Antioxidant and antiproliferative activities of heated sterilized pepsin hydrolysate derived from half-fin anchovy (Setipinna taty)

In this paper we studied the antioxidant and antiproliferative activities of the heated pepsin hydrolysate from a marine fish half-fin anchovy (HAHp-H). Furthermore, we compared the chemical profiles including the amino acid composition, the browning intensity, the IR and UV-visible spectra, and the molecular weight distribution between the half-fin anchovy pepsin hydrolysate (HAHp) and HAHp-H. Results showed that heat sterilization on HAHp improved the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical-scavenging activity and reducing power. In addition, the antiproliferative activities were all increased for HAHp-H on DU-145 human prostate cancer cell line, 1299 human lung cancer cell line and 109 human esophagus cancer cell line. The contents of free amino acid and reducing sugar of HAHp-H were decreased (P < 0.05). However, hydrophobic amino acid residues and the browning intensity of HAHp-H were increased. FT-IR spectroscopy indicated that amide I and amide III bands of HAHp-H were slightly modified, whereas band intensity of amide II was reduced dramatically. Thermal sterilization resulted in the increased fractions of HAHp-H with molecular weight of 3000-5000 Da and below 500 Da. The enhanced antioxidant and antiproliferative activities of HAHp-H might be attributed to the Maillard reaction.     

壳聚糖-胰蛋白酶抑制剂复合可食性膜的制备及抗黄曲霉活性

为探索新型生物膜材料的制备方法及抗黄曲霉活性,以壳聚糖和大豆胰蛋白酶抑制剂(TI)提取物为原料,甘油为增塑剂,利用溶液共混流延法制备壳聚糖-TI-甘油复合可食性膜,测试其厚度、表观结构、力学性质、透光率、水蒸气透过率及抗黄曲霉侵染活性。结果表明,当壳聚糖浓度为18mg/mL、TI浓度2mg/mL、甘油浓度12mg/mL和干燥温度45℃时,制备复合膜具有优良抗黄曲霉活性,且综合理化性能最佳。制备壳聚糖-TI-甘油复合膜液涂膜于花生上,接种黄曲霉培养后发现,复合膜对于黄曲霉侵染具有较强的抵抗和抑制作用。     

四川豌豆种质资源白粉病抗性及分子鉴定

豌豆白粉病是由白粉菌（Erysiphe pisi D. C.）引起的豌豆最重要的病害之一,控制豌豆白粉病最经济有效且环保的方法是种植抗病品种。在温室条件下对400份豌豆种质资源进行白粉病抗性鉴定,同时利用7个与已知豌豆抗白粉病基因连锁的分子标记进行基因型鉴定。结果表明,在400份资源中,有8份表现免疫,3份表现抗病,5份表现抗感分离,其余384份均为感病;16份抗性资源中有10份来自于四川省中部不同纬度地区,其余6份为国外引进资源;7个分子标记将400份种质资源分为39个标记基因型,其中16份抗性资源分为7个标记基因型。上述抗性资源及其标记基因型可有效应用于豌豆白粉病抗性育种的研究中。     

基于颜色特征的马铃薯绿皮检测

提出了一种基于颜色特征的马铃薯绿皮检测方法,该方法以颜色特征分析为基础,结合BP神经网络,实现对马铃薯绿皮缺陷的检测.首先建立马铃薯图片采集系统,采集丰富的绿皮马铃薯和优质马铃薯图像并对图像进行彩色图像增强.对绿皮缺陷和优质区域的颜色特征进行深入分析,提取出相对独立的特征参数R、G、B、H、P/G、B/(R+G).构建...     

烤烟常规化学成分与氢氰酸关系研究

为了明确氢氰酸释放量与烟叶常规化学成分的关系,本研究以全国主要烤烟区域的代表性等级烟叶为材料,运用数理统计相关和回归方法分析了两者之间的关系。结果表明:烟叶中的总氮含量(x_1)、总糖含量(x_2)、钾氯比(x_3)对主流烟气中的氢氰酸释放量(y)有重要影响,回归方程为:y=1.98+120.08x_1+1.50x_2-3.20x_3,其中总氮、总糖含量与氢氰酸释放量呈正相关,钾氯比与氢氰酸释放量呈负相关。因此,在烟叶生产或叶组配方中可通过生产或选择钾氯比高、总氮和总糖含量相对较低的烟叶降低氢氰酸释放量。     

Modeling moisture absorption process of wood-based composites under over-saturated moisture conditions using two-part equations

The objective of this study was to investigate the moisture absorption process for wood-based composites subjected to over-saturated moisture conditions. Two stages are comprised in the moisture transfer process at the over-saturated moisture conditions, an initial stage which is the moisture transfer process mainly under fiber saturation point (FSP), and a second stage which is the moisture transfer process beyond the FSP. A model was developed based on two-part equations to describe the process, from which three coefficients (k ₁ , k ₂₁ , and k ₂₂) can be used to quantitatively describe the moisture transfer process under the conditions. Two different wood-based composites, wood fiberboard and wood fiber/polymer composites (polymer content: 30%), were used to test the model at four different ambient temperatures (30, 45, 62, and 80°C). It was shown that the two-part equation can accurately describe the moisture absorption process under over-saturated moisture conditions. The moisture absorption rate in the initial stage was about 30–60% greater than that in the second stage for most of the cases evaluated in this study. The higher the temperature, the greater moisture absorption parameters were obtained. At both moisture absorption stages (below FSP and above FSP), the calculated activation energy for the moisture absorption rate of wood fiberboard was very close to that of wood fiber/polymer composites.