冷榨亚麻籽油的流变特性研究

通过低温压榨亚麻籽获得冷榨亚麻籽油(cold-pressed flaxseed oil, CFO),并分析了其主要理化指标,着重研究CFO的静态流变特性和动态流变特性,同时分别采用Casson、Herschel-Bulkley和Bingham模型对其流体行为进行拟合,并采用Arrhenius方程分析其粘度热动力学参数。研究结果表明：在剪切速率为0.1～200 s-1下,CFO由非牛顿流体逐渐转化为牛顿流体;当剪切速率大于10 s-1时,CFO呈牛顿流体;同时分析得出CFO的粘度活化能为3 095.4 cal/mol;CFO的粘度、剪切应力、损耗模量、塑性稠度系数、高剪切极限粘度和稠度系数随着温度升高而降低,但是温度变化对CFO的贮能模量影响不显著;另外通过比较3个流变模型得出Bingham模型适用于CFO。      

大豆7S球蛋白亚基相对含量与品质性状间的相关分析

以7S球蛋白亚基组成各异的稀有大豆种质为试材,系统分析了7S球蛋白三个主要亚基（α΄- 、-和β-亚基）的相对含量与品质性状之间的相关性。结果表明：(1) -亚基的相对含量与蛋白质总量呈显著负相关;α΄-与-亚基的相对含量与氨基酸组份间的负相关多达到显著或极显著水平;β-亚基的相对含量与蛋氨酸、胱氨酸和精氨酸的含量呈显著正相关,与苏氨酸呈极显著正相关。（2）脂肪含量与α΄-、-亚基的相对含量呈显著负相关,与-亚基的相对含量呈显著正相关;α΄-亚基的相对含量与亚麻酸的含量呈极显著的正相关;-亚基的相对含量与棕榈酸呈显著负相关,与亚油酸含量呈显著正相关,与硬脂酸和亚麻酸含量呈极显著正相关。（3）亚基组成表现分别为（α΄+α）-亚基缺失和α΄-亚基缺失的日B-1和日A-5是具有巨大育种潜力的优异种质。（4）通过遗传学的手段调整亚基含量,是选育“双高”（高蛋白、高脂肪）品种的新思路。     

动态超高压改性芒果皮渣膳食纤维对果酱流变特性的影响

本研究以芒果皮渣为研究对象,采用动态超高压技术处理芒果皮渣膳食纤维,研究其粒度、膳食纤维含量以及添加了该膳食纤维对果酱流变特性的影响。结果表明：超高压改性提高了芒果皮渣膳食纤维的溶解性;随着压力的增大,膳食纤维粒径先增大后减小再增加,120 MPa时粒径达到18.218 μm。流变特性研究发现,芒果皮渣膳食纤维/果酱复配体系为非牛顿流体,具有假塑性流体特征;果酱粘度随着剪切速率的增大而减小,存在明显的剪切稀化现象;动态粘弹性测试结果表明,果酱复配体系的贮能模量（G′）与损耗模量（G′′）均随角频率的增加而呈上升趋势,损耗正切值也随着压力的增加而增加,在150 MPa时流体性质最明显。     

野燕麦对油菜生长的影响及其经济阈值

采用添加系列试验和模型拟合的方法研究了不同野燕麦密度下油菜各生长性状的变化规律。结果表明,油菜在野燕麦的竞争干扰下,植株高度、分枝数、角果数及千粒重均随其密度的增加而显著降低,而第一分枝高度则不断增加。野燕麦能显著降低油菜植株间的透光率,其对田间25 cm高处的透光率影响较大,对75 cm和50 cm高处的透光率影响相对较小。野燕麦密度为5株&#8226;m-2时油菜产量显著降低,当其密度达到160株&#8226;m-2以上时,可使油菜减产达90%以上。对数模型y = 15.436lnx + 8.475可以较好地拟合野燕麦与油菜产量损失间的关系（P<0.0001）。油菜田野燕麦人工防除的经济阈值为1.15株&#8226;m-2,使用精噁唑禾草灵化学防除的经济阈值为0.70株&#8226;m-2。     

寡糖诱导向日葵活性氧代谢的变化

为了解寡糖诱导对活性氧代谢的效应,本研究通过寡糖喷雾处理向日葵叶片,测定诱导后不同时间的向日葵叶片O2-&#8226;产生速率和H2O2含量,并且进行了活性氧的原位检测,结果显示：在寡糖诱导后一段时间活性氧O2-&#8226;产生速率、H2O2含量明显上升,O2-&#8226;在3 h 达到高峰;H2O2在3 h到6 h均处于较高水平,6 h达到最高峰。原位染色反应也显示O2-&#8226;和H2O2在3 ~6 h积累明显。说明寡糖诱导可以导致向日葵植株早期活性氧的积累。     

橄榄浓缩汁流变学特性

利用MCR301高级流变仪及NDJ-7型旋转粘度计测定了橄榄浓缩汁流变特性值并绘制其流变曲线。结果表明：橄榄浓缩汁为非牛顿流体,拟合的流变特性方程为y=10.234x0.560 8,流变行为指数n＜1,因此其在测量范围内为假塑性流体。阿累尼乌斯方程能较好地反映橄榄浓缩汁温度对粘度的影响,数学模型η=Bexp（AC）能较好地反映橄榄浓缩汁浓度对粘度的影响,橄榄汁浓缩过程温度和浓度对粘度的综合影响可用数学模型η=K1exp（Ea/RT+K2C+K3C2）来表示。利用这些回归模型可预测和控制橄榄浓缩汁在实际生产中不同条件下的粘度。     

金柑汁浓缩过程流变特性及其动力学模型的研究

研究金柑汁浓缩过程中温度、浓度与粘度的关系,确定了金柑浓缩汁的流变特性,同时建立浓缩动力学模型。通过回归分析发现,在研究的条件范围内,金柑浓缩汁表现为非牛顿假塑性流体;温度对粘度的影响可用阿利尼乌斯(Arrhenius)方程来表示,表现为随温度的升高,金柑浓缩汁粘度随之下降;浓度对粘度的影响可用指数方程来表示,表现为随浓度升高,金柑浓缩汁粘度随之增大。推导出温度和浓度对金柑浓缩汁粘度综合影响的数学模型方程式,为实现金柑浓缩汁产业化生产提供理论依据。     

NaCl胁迫对续随子离子吸收及荧光特性的影响

以续随子为材料采用温室盆栽法,研究了NaCl胁迫处理对其生长发育、离子分布和叶绿素荧光特性的影响。结果表明：(1) 25mmol&#8226;L-1 NaCl胁迫时续随子幼苗的鲜重、干重和株高比对照略有下降,但不显著;随着NaCl浓度的继续增加,三指标均显著降低。(2)盐胁迫影响植物组织的离子分布,Na +浓度增加时,K+、Ca2+和Mg2+浓度均持续下降,K+/ Na+、Ca2+/ Na+、Mg2+/ Na+ 也急剧下降。(3) NaCl胁迫下,续随子幼苗叶片的初始荧光(Fo)、最大荧光(Fm)、PSⅡ实际光化学效率均降低。但在0～25 mmol&#8226;L-1NaCl浓度下,Fo、Fm与对照差异不显著。可见,NaCl胁迫下,续随子产生了光合作用的光抑制伤害。     

吉林省大豆品种遗传改良过程中茎部性状的演变

以吉林省1923-2005年育成的30个大豆（Glycine max）品种为材料,通过2005和2006两年田间试验对茎部性状演化及其与产量的关系进行研究。结果表明,产量随育成年代呈线性增加,根据回归方程计算,产量从1923年的1197.80kg&#8226;hm-2增加到2005年的2305.545 kg&#8226;hm-2,82年来增加了1107.73kg&#8226;hm-2,平均每年增加14.60kg&#8226;hm-2;不同年代育成大豆产品种间茎部性状差异显著,植株高度降低,倒伏指数下降,茎直径明显增加,主茎分枝减少,节数增多,节间明显缩短,植株抗倒伏能力随着年代的演替明显增强,但株高不宜继续降低,应保持在80cm左右为宜;通过相关分析表明,产量与株高、分枝数、倒伏指数、节间长度相关均达到显著水平（P≤0.05）,并且株高、节数和节间长度对产量产生的直接效应较大,说明在遗传改良过程中茎部性状与产量关系密切,在品种选育和高产栽培过程中可以作为选择的依据。     

降解除草剂异噁草酮细菌的分离、鉴定及生长特性

利用长期施用长残留除草剂的土壤，采用高压富集的方法，从两种培养液中共分离出3株细菌，根据菌株的形态特性和生理生化特征，对此3个菌株进行了初步鉴定： W2为短杆菌属(Brevibacterium)； Y1和X同为芽胞杆菌属（Bacillus）；W2、Y1和X的最适生长温度分别是30℃、35℃和30℃；W2培养基的pH值为6.0～9.0，Y1和X的最适pH值为6.0～8.0；W2生长最适异噁草酮的浓度是200mg a..i.&#8226;L-1，Y1和X生长最适异噁草酮的浓度是100mg a..i.&#8226;L-1。     

Rheological properties of starches with different amylose/amylopectin ratios

The rheological properties of corn starches with different amylose/amylopectin ratios (80/20, 50/50, 23/77, and 0/100) were systematically studied by Haake rheometry. The starches were initially pre-compounded with water to designated moisture content levels using a twin-screw extruder. A single-screw extruder with a slit capillary die was then used to characterize the shear stress and melt viscosity characteristics of sample pellets, as a function of both moisture content (19–27%) and extrusion temperature (110–140 °C). The melts exhibited shear thinning behavior under all conditions, with the power law index (0 < n < 1) increasing with increasing temperature and moisture content in the majority of cases. The higher the amylose content, the higher is the viscosity (for example, η increases from 277 Pa s to 1254 Pa s when amylose content increases from 0% to 80% under a certain condition), which is opposite to the sequence of molecular weight; amylopectin-rich starches exhibited increased Newtonian behavior. These rheological behaviors are attributed to the higher gelatinization temperature of amylose-rich starches, and in particular the multiphase transitions that occur in these starches at higher temperatures, and the gel-ball structure of gelatinized amylopectin.     

Constitutive equations for dilute bubble suspensions and rheological behavior in simple shear and uniaxial elongational flow fields

A theoretical model is proposed in order to investigate rheological behavior of bubble suspension with large deformation. Theoretical constitutive equations for dilute bubble suspensions are derived by applying a deformation theory of ellipsoidal droplet [1] to a phenomenological suspension theory [2]. The rate of deformation tensor within the bubble and the time evolution of interface tensor are predicted by applying the proposed constitutive equations, which have two free fitting parameters. The transient and steady rheological properties of dilute bubble suspensions are studied for several capillary numbers (Ca) under simple shear flow and uniaxial elongational flow fields. The retraction force of the bubble caused by the interfacial tension increases as bubbles undergo deformation. The transient and steady relative viscosity decreases asCa increases. The normal stress difference (NSD) under the simple shear has the largest value whenCa is around 1 and the ratio of the first NSD to the second NSD has the value of 3/4 for largeCa but 2 for smallCa. In the uniaxial elongational flow, the elongational viscosity is three times as large as the shear viscosity like the Newtonian fluid.     

Processing and characterization of liquid crystalline copoly-(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate)/polycarbonate blends

Liquid crystalline (LC) poly(ethylene terephthalate-co-2(3)-chloro-1,4-phenylene terephthalate) (50/50, mole/mole) [PECPT] was synthesized and blended with polycarbonate (PC). LC properties of PECPT and thermal, morphological, and rheological behaviors of the PECPT/PC blend were studied. PECPT showed the nematic LC phase and much longer relaxation time than poly(ethylene terephthalate) (PET). The apparent melt viscosity of PECPT was one third of that of PET. An abrupt torque change was observed during the blending process due to the orientation of LC domains. For the blends containing 10∼30 wt% of PECPT, the complex viscosities were higher than that of PC. As PECPT content increases above 40 wt%, shear thinning was observed. The lowest complex viscosity was obtained at 40∼50 wt%. Transesterification of PECPT and PC was confirmed by the selective chemical degradation of carbonate groups in PC.     

Effect of wheat dietary fibres on bread dough development and rheological properties

Several fractions of wheat fibres were isolated from starchy endosperm, aleurone layer and bran, and characterized for their hydration properties and arabinoxylans (AX) content. The influence of their addition, up to 10%, to standard flour was studied through mixing tests, and rheological tests at small and large deformations. The effect of insoluble AX on dough development was accounted for by their capacity to retain water, whatever their origin and percentage of addition. The addition of insoluble AX increased the viscoelastic plateau modulus. The addition of soluble and insoluble AX to the dough did not modify the overall dough flow behaviour in shear, characterized by a Newtonian plateau at low shear rates followed by shear-thinning behaviour at larger shear rates. This behaviour could be fitted by the Cross model. The addition of water soluble AX modified the Newtonian viscosity value. Conversely, the addition of insoluble ones increased dough consistency, probably through a filler-like effect in the dough matrix.     

Comparison of Mineral Oil and Rapeseed Oil Used for the Protection of Seed Potatoes against PVY and PVM Infections

The aim of this research was to compare the effectiveness of mineral oil with rapeseed oil in the protection of potato seeds against Potato virus Y (PVY) and Potato virus M (PVM) infection. The research was carried out under field conditions in the north of Poland, in the Department of Potato Protection and Seed Science of the Plant Breeding and Acclimatization Institute??National Research Institute at Bonin. The effects of oil protection on potato seed infection by viruses, yield, and its structure and phytotoxity were assessed. Two rapeseed oils and one mineral oil were used: Olejan 85 EC (85% of natural rapeseed oil), alimentary oil Marlibo (100% of natural rapeseed oil) and Sunspray 850 EC (98.8% mineral oil+1.2% emulsifier). The effectiveness of oils in protection against PVY and PVM tuber infection was tested on two cultivars (Clarissa and Rosalind), which have a different level of resistance to the two viruses. The assessment of phytotoxicity was carried out on 10 potato cultivars from different earliness groups (Augusta, Bryza, Cekin, Clarissa, Impala, Krasa, Rosalind, Satina, Velox). Two oil concentrations, 2% and 4% were applied. During the growing period, eight to nine oil treatments were applied at 7-day intervals. The effectiveness of rapeseed oils against PVY and PVM was much weaker than that of the mineral oil and for the susceptible cultivar the percentage infected tubers did not differ significantly from untreated crops. However, Olejan 85 EC deserves attention as it significantly reduced PVY infection across years in the more resistant cultivar, especially in the case of a lower concentration (2% vs. 4%). When there are no other means of protection to use on organic seed plantations, this oil can be used as an alternative, especially in the case of cultivars which are moderately resistant to PVY. A disadvantage of its application may be the fact that in some years symptoms of phytotoxicity on potato plants were recorded and a lowering of tuber yield.     

凝胶剂种类对双低菜籽油基凝胶油结构及性能的影响

以双低菜籽油为基料油，选用12-羟基硬脂酸、蜂蜡、葵花蜡、硬脂酰乳酸钠、单甘酯、豆甾醇、薯蓣皂素、肉桂酸作为凝胶剂，在不同浓度（2%，4%和6%，m/m）条件下制备菜籽油基凝胶油，通过持油率、流变特性测定、偏光显微镜、X-射线衍射和傅里叶红外等技术表征其物理特性及微观结构。经外观及持油率结果表明，除蜂蜡与肉桂酸以外，其余的凝胶剂均能在低浓度（2%）下形成稳定凝胶油，且当浓度为6%时，除薯蓣皂素与肉桂酸外，其他体系所形成的凝胶油持油率均能达到94%以上；经流变分析发现，12-羟基硬脂酸凝胶油G′值大且结构不易受外力而改变，豆甾醇形成的凝胶油热稳定性最好（相转变温度93.4°C）；微观结构结合红外分析表明，12-羟基硬脂酸在菜籽油中形成致密纤维状的网络结构，豆甾醇、薯蓣皂素在油中形成棒状晶体，而肉桂酸呈稀疏片状晶体，其他凝胶内部为小颗粒结晶，且凝胶油的晶型及晶体之间的作用力主要取决于凝胶剂的分子结构。     

Pasting,thermal and rheological properties of octenylsuccinylate modified starches from diverse small granule starches differing in amylose content

Waxy maize (a standard starch of normal granule size) and five small granule starches from different botanical sources (rice, wheat B type, oat, quinoa and amaranth) were subjected to 2-octenyl-1-succinic anhydride (OSA) modification. Changes of pasting, gel texture, thermal and rheological properties were investigated. Different small granule starches showed quite different property changes after OSA modification. Pasting viscosity was generally increased in OSA starches, among which OSA oat starch had notably high peak and breakdown viscosity but low setback viscosity. Gel hardness of rice, wheat B type, oat and quinoa starches was reduced by OSA treatment, whereas that of waxy maize and amaranth starches was increased. Amylose content was considered to be the major factor influencing pasting, gel and thermal property of OSA starches. Esterification increased pseudoplastic flow behavior of all starches, while OSA oat starch uniquely had reduced flow consistency coefficient. The dynamic rheological properties were also changed differentially among OSA starches. Viscoelastic properties of rice, wheat B type, oat and quinoa starches were increased after OSA treatment, whereas those of waxy maize and amaranth starches were decreased. This study showed that diverse functionalities from OSA small granule starches may fulfil different demands in product development.     

环氧化天然橡胶的流变行为和力学行为

用橡胶加工分析仪研究了环氧化天然橡胶ENR）的流变行为和力学行为,并和天然橡胶（NR）进行了比较。结果表明,在高剪切速率区,ENR和NR的表观粘度都随剪切速率的增加而降低,但 ENR表观粘度的降低幅度比NR小。ENR和NR的粘流活化能均随剪切速率的增加先降低而后又增加,但ENR粘流活化能比NR大。在大应变范围,ENR的转矩S'的应变响应明显与NR 不同。在高频区,随温度增加NR的G'略有降低,而ENR的则明显下降。