水分调控对两种筋力型小麦品种籽粒淀粉糊化特性的影响

在池栽、防雨条件下，研究了不同灌水对两种筋力型小麦品种淀粉糊化特性的影响。结果表明，两种筋力型品种间淀粉粘度参数差异达0．01显著水平，强筋型品种豫麦34稀懈值、糊化温度低于弱筋型品种豫麦50，而最终粘度、反弹值、高峰粘度和低谷粘度大于豫麦50。水分调控对两种筋力型品种淀粉糊化特性有显著的影响，豫麦50主要粘度参数以灌4水处理和抽穗期灌1水处理较好，灌拔节1水处理较差；而豫麦34以灌1水处理较好，灌4水处理较差，其中拔节期灌1水与抽穗期灌1水差异不显著。分析两品种粘度参数之间的关系，豫麦50主要粘度参数间达显著相关水平，而豫麦34多数粘度参数间相关不显著，在栽培措施上豫麦50比豫麦34具有同步提高淀粉品质的可能性。     

淀粉凝胶力学性能的研究

淀粉凝胶的力学性能决定其“力学味觉”或“流变学味觉”如粘弹性、硬度、粗糙感等属性。材料试验机研究的结果表明，在一定的淀粉乳浓度范围内，凝胶强度和弹性模量随淀粉乳浓度的增加而增加，而凝胶弹性则基本保持不变。由于淀粉分子结构之间的差异，导致本试验研究对象——三种淀粉凝胶力学性能之间的不同：凝胶强度的大小为葛根淀粉＞马铃薯淀粉＞玉米淀粉；凝胶弹性为葛根淀粉＞玉米淀粉＞马铃薯淀粉；弹性模量为马铃薯淀粉＞葛根淀粉＞玉米淀粉。     

淀粉粒度对热塑性淀粉性能的影响研究

研究了微细化淀粉结晶度的变化以及淀粉粒度对热塑性淀粉性能的影响,结果表明,淀粉粒度降低的同时,其颗粒团聚作用明显。机械研磨作用能够明显地破坏淀粉分子的结晶结构,导致其结晶度降低,而无序化程度增加。淀粉粒度的适度降低对热塑性淀粉性能有显著改善作用,以中位径d₅₀≈4.23 μm附近的微细化淀粉为原料制备热塑性淀粉,其力学性能,熔体流变性以及生物降解性均较为理想,抗拉强度为21.7 MPa,断裂伸长率为138.3%,28 d土埋生物降解失重率近60%。     

喷灌促进小麦籽粒淀粉积累提高其品质

为研究喷灌和地面灌溉对小麦籽粒淀粉积累及其品质性状的影响,该文以中筋小麦百农矮抗58为试验材料,通过2012-2014年2个生长季的大田试验,以地面灌溉为对照,分析了喷灌对小麦籽粒淀粉及其组分积累过程、淀粉糊化特性等的影响。结果表明:1)与地面灌溉相比,喷灌显著提高了小麦总淀粉和支链淀粉的含量,降低了直链淀粉含量,进而降低了淀粉的直/支比;2)喷灌条件下小麦总淀粉和支链淀粉的积累量较地面灌溉分别显著提高了7.8%~8.0%和12.2%~12.5%(P0.05);3)喷灌条件下小麦直链淀粉的积累量较地面灌溉显著降低了8.3%~11.4%(P0.05);4)Logistics方程模拟淀粉积累过程表明,与地面灌溉相比,喷灌提高了小麦总淀粉和支链淀粉的最大积累速率、平均积累速率,但降低了直链淀粉的最大积累速率、平均积累速率;5)喷灌与地面灌溉条件下淀粉糊化特性表现出明显的不同:除糊化温度和糊化时间差异不显著外,喷灌小麦淀粉的高峰黏度、低谷黏度、稀懈值和最终黏度分别较地面灌溉提高了0.169~0.186、0.053~0.062、0.116~0.124和0.155~0.171 Pa·s(P0.05)。综上,与地面灌溉相比,喷灌有利于中筋小麦成熟期籽粒淀粉积累,并在一定程度上提高了中筋小麦淀粉品质。该研究可为小麦高产优质栽培提供理论依据。     

4种不同甘薯淀粉成分、物化特性及其粉条品质的相关性研究

为了研究不同品种甘薯淀粉性质与其粉条品质之间的关系,本文研究了4种不同淀粉型甘薯(卢选1号、徐薯22、冀薯65和冀薯98)来源淀粉化学成分和物化特性,并分析了甘薯淀粉成分和物化特性与粉条品质间的相关性.结果表明,不同品种间甘薯淀粉由于化学成分的不同而使其物化特性和粉条品质都发生不同程度的变化;通过对甘薯淀粉的成分和物化性质与其粉条品质之间的相关性分析,发现甘薯淀粉的直链淀粉和脂质含量、回生黏度、峰值时间、糊化温度、膨胀势、老化值等指标与甘薯粉条品质呈正相关,而甘薯淀粉的最终黏度、溶解度和粒径等指标与甘薯粉条品质呈负相关.通过综合比较,卢选1号的粉条品质优于其他3个品种的粉条.因此,本研究为合理选择甘薯粉条制备所需淀粉原料提供了理论依据,为进一步选育粉条专用型甘薯提供了基础数据.     

聚乙烯醇/淀粉共聚物包膜材料消泡研究

聚乙烯醇／淀粉共聚物包膜材料在对肥料进行包膜过程中会产生大量的气泡，在肥料表面形成微小孔隙，因此降低了肥料的缓释性能。本试验通过对不同种类的消泡剂消泡效果的研究，削述了消泡剂的消泡机理，并且通过研究确定了改性有机硅型消泡剂和聚二氧化硅型消泡剂消泡效果最好，降低了膜的吸水量和透水性，从而提高了聚乙烯醇／淀粉共聚物包膜肥料的缓释效果。     

淀粉凝胶与植物组织培养II.玉米淀粉凝胶培养基对苹果砧木组培生根诱导的同步化作用

珠美海棠和M26苹果矮化砧木分别在琼脂培养基和玉米淀粉（corn starch）凝胶培养基上进行生根培养，结果玉米淀粉培养基不但提高了两种植物的生根率，而且对生根诱导具有同步化效应。珠美海棠生根苗游离氨基酸含量的高效液相色谱（HPLC）分析表明，琼脂生根培养基上，吲哚丁酸（IBA）诱导了天冬氨酸、谷氨酸、组氨酸、苏氨酸、色、蛋氨酸和谷氨酰胺、丙、酪氨酸的降低，但却提高了精氨酸、缬氨酸、苯丙氨酸、亮氨酸和鸟氨酸的含量。当玉米淀粉替代琼脂后，玉米淀粉培养基不但进一步促进了上述氨基酸含量的降低，而且抑制了精氨酸、缬氨酸、苯丙氨酸等的升高。     

一种稻米直链淀粉含量的简易测定方法

为便于育种利用,对农业部标准中的米质测定方法(NY147-88)作了简化,其测定结果与标准法高度正相关(r=0.9996),两种方法间的测定结果绝对误差小于1.2%。与标准法相比较,简易法具有简单、易操作、样品量少等优点,可用于小样品或育种大群体的筛选测定。     

Net energy,energy utilization,and nitrogen and energy balance affected by dietary pea supplementation in broilers

Pea starch consists predominantly of C-type of amylopectin chain which is more resistant to digestive enzymes than A-type of starch thus slowly digested in poultry. It was hypothesized that the presence of slowly digested pea starch in broiler diets will increase net energy and the efficiency of energy utilization in broilers. Two experiments were performed to investigate starch digestibility of pea at different incubation times (in vitro study) and the effect of dietary pea on heat increment and net energy in broilers using an open-circuit respiratory calorimetry system (in vivo study). One-day-old Ross 308 male broilers were fed a common starter crumble from d 1 to 10 and standard grower diets thereafter. At d 21, birds were transferred to the chambers each housing 2 birds. Each treatment was replicated 6 times with 2 identical runs of 3 replicates per treatment. A wheat-soybean meal-based diet was used as a control and the treatment diet contained 500 g of pea/kg pea. In vitro study showed that pellet processing increased (P < 0.001) starch digestibility, particularly at shorter times for wheat and a much larger response for pea. Birds offered the pea-based diet had lower (P = 0.002) feed intake, lower (P = 0.020) body weight gain, but a similar (P > 0.05) FCR compared to those offered the wheat-based diet. Net energy (NE) and apparent metabolizable energy (AME) values were higher in the pea-based diet than in the wheat-based diet (P = 0.037 for NE and P = 0.018 for AME). Heat production, respiratory quotient, heat increment of feed, efficiency of utilization of gross energy for AME, and efficiency of utilization of AME for NE did not differ (P > 0.05) between the 2 treatments. There was no effect (P > 0.05) of pea on the total tract digestibilities of dry matter, crude protein and ash, but the total tract digestibility of starch was higher (P = 0.022) in the pea-based diet compared to the wheat-based diet. This study provides insight into the energy metabolism of broilers offered a pea-based diet and indicates that dietary pea supplementation increases dietary AME and NE but has no effect on heat increment of feed and the efficiency of energy utilization in broilers.