贵州毕节地区烤烟有机酸类物质的相关分析和因子分析

以贵州毕节地区8个县(市、区)59个烤后烟叶中部叶样品为供试材料,对烤烟17种有机酸成分进行了相关分析和因子分析,并利用因子得分进行综合评价。结果表明,烤烟有机酸成分间存在显著或极显著的相关性,且适合对原数据做因子分析。对有机酸成分进行因子分析得到5个公因子,即不饱和脂肪酸因子、吃味因子、草酸因子、十七酸因子和二十酸因子。因子分析法综合评价的结果与感官评吸结果基本一致,为评价烤烟品质提供了科学的依据和方法。     

贝加尔唐松草微量元素和氨基酸含量测定

应用等离子体发射光谱仪(ICP-AES)和氨基酸分析仪测定了贝加尔唐松草根和茎中的微量元素和氨基酸含量。结果表明,贝加尔唐松草根和茎中的钾、钙和镁含量非常高,铁、钠、锌和锰含量次之,铜、镍和钴含量较低,10种微量元素含量的质量分数大小依次为:钾>钙>镁>铁>钠>锌>锰>铜>镍>钴;钾元素含量根部<茎部,其他9种微量元素含量均是根部>茎部。贝加尔唐松草根和茎中含有17种丰富的游离氨基酸,含量均为根部>茎部,其中人体必需氨基酸含量较高,根和茎中7种必需氨基酸质量分数分别占氨基酸总量的44.66%、41.83%。甘肃贝加尔唐松草可作为一种具有开发前景和应用价值的野生药材。     

日本金线鱼肌肉营养成分分析

对日本金线鱼(Nemipterus japonicus)的含肉率和肌肉营养成分进行测定并分析。结果表明,日本金线鱼含肉率为74.96(±1.99)%,粗蛋白含量为19.48(±0.21)%,粗脂肪含量为2.66(±0.02)%,水分含量为76.37(±0.34)%,粗灰分含量为1.35(±0.02)%。肌肉蛋白中17种氨基酸占鲜样的13.71%,其中人体必需氨基酸占鲜样的6.26%,占氨基酸总量的45.66%,必需氨基酸与非必需氨基酸的比例为89%,符合FAO/WHO的标准。第一、第二限制性氨基酸均为含硫氨酸(蛋氨酸+胱氨酸)和苏氨酸,必需氨基酸指数为65.30,4种鲜味氨基酸含量为5.39%,占氨基酸总量的39.31%。     

缺氮复氮处理对玉米根系生长、根系活力、硝态氮及氨基酸含量的影响

为明确缺氮复氮处理对根系生长、根系活力、硝态氮含量及氨基酸含量的影响,对水培玉米幼苗进行研究。结果表明,缺氮处理的根系总长、根表面积、分根数比正常处理的较大,复氮处理后各测定指标均有一定恢复;缺氮处理根系活力显著下降,降幅达50.91%,复氮处理后根系活力有所恢复,但仍然降低42.15%;缺氮根系的NO₃^- N含量比正常处理降低76.21%,复氮处理后NO₃^- N含量仍然降低40.97%;缺氮根系的天冬氨酸、苏氨酸、丝氨酸、谷氨酸、脯氨酸、甘氨酸和丙氨酸的含量明显下降,复氮处理后这些氨基酸含量仍然低于正常处理。     

梅花鹿茸、马鹿茸不同部位氨基酸、总磷脂、钙、磷含量的研究

本文对梅花鹿茸、马鹿茸不同部位氨基酸、总磷脂、钙、磷含量进行了分析，结果表明：梅花鹿茸、马鹿茸不同部位都含有丰富的氨基酸，其中含有７种以上的人体必需氨基酸。各个部位氨基酸的总量，必需氨基酸的含量及总磷脂的含量由基部到顶端逐渐增加，钙、磷的含量则由基部到顶端逐渐减少。     

从发酵糠醛渣中提取生化腐植酸的技术研究

[目的]获得从腐熟糠醛渣中利用碱提酸析方法制备生化腐植酸的最优工艺.[方法]以发酵糠醛渣为原料,采用碱提酸析法提取生化腐植酸(BHAs).通过四因素四水平的正交实验,考察固液比(发酵糠醛渣与水的质量比)、碱液浓度、提取温度、提取时间对生化腐植酸提取率的影响,再利用盐酸调节提取液的pH值,使生化腐植酸沉淀析出,固液分离烘干后得到成品生化腐植酸.[结果]最佳的腐植酸提取工艺条件为:碱提步骤固液比为1:8、碱液浓度为8％、提取时间为2.5 h、提取温度为70℃,酸析步骤pH为2.5.得到腐植酸含量为76％的固体生化腐植酸成品,其提取率为49％.[结论]该研究为碱提酸析法从发酵糠醛渣中分离提纯BHA提供了理论依据.     

Processing of 13C glucose in mineral soil from aspen,spruce and novel ecosystems in the Athabasca Oil Sands Region

Microbial composition is known, on similar soil types, to vary based on differing organic matter inputs, or stand composition. Fine-textured luvisolic soils, which dominate the upland boreal forests of Western Canada, support a canopy cover of aspen (Populus tremuloides Michx.), white spruce (Picea glauca (Moench) Voss) or a mixture of the two. These soils then reflect different belowground biogeochemical processing of organic matter. Novel, anthropogenic soils formed from a combination of peat litter and fine textured mineral soil, are now also a part of the landscape in the western boreal. This study set out to determine if a simple labeled compound (¹³C glucose) was processed differently by soils from the two dominant stand types (aspen and spruce) and from an anthropogenic (newly reclaimed) site. Results indicate that while all three soils rapidly incorporated and respired the labeled carbon, each maintained a distinct microbial community structure (as evidenced by phospholipid fatty acid analysis) throughout the 300 hour experiment. Therefore soils with different microbial communities from varied organic matter inputs decompose organic carbon by different processes, even in the case of simple labile compounds.     

The Effects of Peptide-Precipitating Lignosulphonic Acids on the Proteolytic Activity of Pepsin in Vitro and on the Response of Pigs to an Ulcer Inducing Diet

The inhibitory effect of peptide-precipitating lignosulphonic acids on the proteolytic activity of pepsin in vitro has been studied. When an unfractionated lignosulphonic acid preparation was used, total inhibition of the activity of 5 µg crystalline pepsin was obtained by addition of about 15 mg of lignosulphonic acids.The greatest inhibitory effect was seen with the high-molecular weight lignosulphonic acids, but an effect was also seen with middle-and low-molecular weight lignosulphonic acids.A reduction in the inhibitory effect was seen when the experiments were performed in the presence of arginine. The inhibition mechanism is discussed in relation to the peptide-precipitating ability of the lignosulphonic acids.No obvious protection against the appearance of stomach ulcers in four pigs receiving an ulcerogenic diet was seen.     

Optimum soybean lecithin contents in microdiets for gilthead seabream (Sparus aurata) larvae

The aim of the present study was to determine the optimum dietary levels of soybean lecithin (SBL) for seabream (Sparus aurata) larvae, and its influence on production performance and digestive enzymes activity. Larvae were fed five formulated microdiets with five levels of SBL. Complete replacement of live preys with the experimental microdiets for seabream larvae at 16 dph produced over 55% survival rates, particularly in fish fed with the highest levels of SBL. Moreover, increase in dietary SBL up to 80 g kg⁻¹ significantly improved larval growth, leading to high final total length and body weight. An increase in alkaline phosphatase activity with the elevation up to 80 g kg⁻¹ SBL was also found denoting a better maturation of the digestive system. Besides, there was a stimulatory effect of dietary SBL on PLA2 activity. Finally, increasing dietary SBL lead to better utilization of dietary highly unsaturated fatty acid, as it was reflected in their higher content in both neutral and polar lipid of the larvae. In summary, elevation of dietary SBL up to 80 g kg⁻¹ in microdiets for seabream significantly improved digestive enzymes activities, enterocyte maturation, utilization and deposition of dietary essential fatty acids and larval growth, as a consequence of a better digestion, absorption, transport and deposition of dietary nutrients.