壳聚糖-铜杀菌剂的合成工艺及其Cu^2＋的解吸性能研究

[目的]利用壳聚糖开发载体化铜制剂,既可避免铜离子浓度过高的药害,又可以延长药效期.[方法]探讨了壳聚糖对Cu^2＋吸附量的影响因素,最佳条件下合成壳聚糖-铜杀菌剂,研究其在水中Cu^2＋的释放动力学.[结果] CTS-Cu的最佳合成工艺：硫酸铜浓度20g/L,壳聚糖、硫酸铜质量体积比为1/40,反应温度40℃,吸附时间90 min.载铜壳聚糖在水中Cu^2＋的释放量随时间的延长而增加,8h即可达到较高浓度,在36 h后基本达到稳定释放.[结论]为其农业生产应用奠定基础.     

壳聚糖涂膜对大蒜保鲜效果的研究

采用壳聚糖作为涂膜保鲜材料,在常温条件下研究不同浓度壳聚糖的单膜和复合膜对大蒜贮藏期间主要理化特性的变化.结果表明,1.50%壳聚糖单膜和壳聚糖-玉米淀粉复合膜均可有效抑制大蒜的呼吸强度,保持大蒜的水分含量、硬度、可溶性同形物含量和总糖含量,以壳聚糖-玉米淀粉复合膜的保鲜效果最为理想.     

狭叶四照花果实保鲜及黄酮提取研究

[目的]研究狭叶四照花果实保鲜及黄酮的提取。[方法]用5种不同溶剂的壳聚糖作保鲜膜分别对狭叶四照花果实进行处理。[结果]结果表明,5种不同溶剂的壳聚糖保鲜膜均能不同程度地延缓果实衰老,其中以醋酸作溶剂效果最好,比其他溶剂的保鲜效果平均高出18%以上。处理8 d后,第5组的好果率仍达85%以上,Vc、还原糖、有机酸含量分别为保鲜前的69%、101%、53%以上,而未处理的已经大部分干瘪失去食用价值。此外,以70%乙醇作为提取溶剂更为有利于黄酮的提取,狭叶四照花果实和叶黄酮含量分别为10.26、55.12 mg/g。[结论]有利于开发狭叶四照花果实资源,为经济建设服务。     

水分胁迫下壳聚糖对菜豆种子萌发的影响

针对生产中菜豆出苗难、保苗难等问题,在盆栽条件下,通过控制土壤水分来模拟干旱胁迫环境,研究了壳聚糖不同浓度和药种比处理对菜豆种子萌发的影响;结果表明：壳聚糖能促进种子萌发,对菜豆种子发芽率、发芽势、发芽指数、活力指数等均有提高作用,当浓度为2%、药种比1:50 时,发芽率最高;浓度为1.5%、药种比1:50 时的发芽势最高,相同药种比下,浓度为1.5%和2%的发芽指数最高;浓度为1.5%和2%、药种比为1:50 时,活力指数达到最大。因此,当壳聚糖浓度为1.5%~2%,药种比为1:50 时,其处理效果最好,可为菜豆抗旱种衣剂的进一步研究提供基础。     

Effects of Yeast Oligosaccharide Diet Supplements on Growth and Disease Resistance in Juvenile Nile Tilapia,Oreochromis niloticus

Commercially available yeast and yeast subcomponents consisting mainly of β-glucan or oligosaccharide feed additives were added to diets of juvenile (12–18g) Nile tilapia (Oreochromis niloticus) at rates recommended by suppliers. Three experiments were conducted following a basic protocol with varied rates of supplementation, duration of feeding, and stocking densities. Experimental diets were fed twice daily to apparent satiation for a period of two or four weeks, at the end of which feed consumption and weight gain were measured. Following the experimental feeding period, serum components, including protein and immunoglobulin concentrations, as well as lysozyme and complement activities, were measured. A disease challenge was conducted with pathogenic isolates of Streptococcus iniae or Edwardsiella tarda. Weight gains were not significantly different in fish fed the supplemented diets when compared to the control diet. There were significant differences in fed intake within individual experiments; however, this effect was not consistent in all three experiments. Overall feed efficiency was not significantly affected by diet. There were no differences in serum components of fish sampled at two or four weeks. Fish fed the experimental diets did not have lower mortality or morbidity after disease challenge compared to fish fed the control diets. Specific antibody against S. iniae or E. tarda measured by ELISA did not reveal differences in the fish surviving the challenge. We conclude that the incorporation of these commercial yeast component products into the diet of juvenile Nile tilapia at these rates and for these feeding periods had no effect on growth, serum components, antibody responses, or survival following S. iniae or E. tarda infection.     

壳聚糖制备工艺的研究

利用河蟹壳制备壳聚糖的改进工艺,对脱乙酰度、粘均分子量2项主要指标进行测定.经过极差分析找到了最佳工艺条件,即浓度为15%的氢氧化钠100℃脱蛋白1 h,浓度为15%的盐酸25℃脱钙4.5 h,浓度为45%的氢氧化钠130℃脱乙酰反应3 h.在改进工艺条件下,壳聚糖脱乙酰度在85%以上,粘均分子量大于70万,免去氧化脱色阶段,避免在氧化脱色过程中造成壳聚糖的降解,产物色泽呈灰白或肉色,保证了壳聚糖的质量.这表明,利用盘锦河蟹壳制备壳聚糖,从而改进工艺是可行的.     

壳聚糖的生理功能及其在肉鸡养殖中的应用

壳聚糖是目前在生物体中发现的唯一碱性多糖,具备降低体脂、抑菌抗菌和增强免疫等多种生理功能,被认为是一种极具潜力的绿色饲料添加剂,在畜禽生产方面有广泛的应用前景。对壳聚糖的生理功能及其对肉鸡脂肪代谢、鸡肉品质、生产性能和免疫机能的影响予以综述,为其进一步的开发利用提供理论依据。     

海藻酸钠和壳聚糖对莲藕贮藏效果及品质的影响

在常温（25℃）条件下,采用不同浓度的海藻酸钠（SA）和壳聚糖（CTS）涂膜保鲜剂对莲藕进行处理,对其采后贮藏效果和品质进行研究。结果表明：适宜浓度的SA 和CTS 涂膜处理可以有效的抑制莲藕表皮褐变,减小失重率,显著抑制莲藕VC、可溶性糖含量的降低和细胞膜透性升高。其中1.0%SA 处理在抑制莲藕表皮褐变,减小失重率,抑制可溶性蛋白含量降低及细胞膜透性上升等方面表现最好;1.25% CTS 和1.5% CTS 处理在抑制莲藕VC 和可溶性糖含量降低方面表现较好。     

香茅草精油/羧甲基壳聚糖复合膜的性能及对沃柑采后青绿霉病防治效果

为探寻安全高效的可食性涂膜应用于沃柑保鲜,以羧甲基壳聚糖（Carboxymethyl chitosan,CMCS）和香茅草精油（XMC）两种天然材料为原料制备复合涂膜材料,并检验复合涂膜材料的理化性质,后以蒸馏水为对照,研究0.5%香茅草精油与1.0%羧甲基壳聚糖复合涂膜处理（0.5% XMC-1.0% CMCS）对沃柑果实青霉、绿霉病害的防控效果及其对果实抗病防御酶活性和果实品质的影响。结果表明,香茅草精油的添加提高了膜的韧性、完整性、粗糙度、不透明度,降低了水蒸气透过率。同时,0.5%香茅草精油与1.0%羧甲基壳聚糖复合处理显著（P<0.05）抑制了沃柑果实青霉、绿霉病的发病率及病斑直径的扩展。此外,与对照组相比,0.5%香茅草精油与1.0%羧甲基壳聚糖复合涂膜处理诱导提高了沃柑果皮中苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、多酚氧化酶（PPO）、几丁质酶（CHI）活性及苯酚、类黄酮、花青素等抗性物质的含量,且在整个贮藏过程中保持了果实品质。综上,香茅草精油的加入提高了复合膜的整体性能,0.5% XMC-1.0% CMCS复合涂膜处理诱导提高了采后沃柑果实的抗病防御酶活性和抗性物质含量,增强沃柑果实抗青绿霉病的能力,维持了果实贮藏品质。     

壳聚糖对水蜜桃汁的澄清效果初报

用壳聚糖对水蜜桃汁进行澄清试验的结果表明,壳聚糖用量为0.3~1.2g/L、温度40~55℃、pH3.0~4.5的工艺条件下澄清水蜜桃汁,透光率达86%以上,果汁中的可溶性固形物含量基本不变。通过正交试验,得出壳聚糖对水蜜桃汁澄清的最适工艺条件是：壳聚糖用量为0.4g/L,温度为40℃,pH为4.5。