凉粉草胶溶液粘度的研究

从温度、PH值、剪切速度、盐、糖和质量浓度这几个方面对凉粉草胶溶液的粘度进行探讨。结果表明,凉粉草胶溶液呈现出牛顿流体或假塑性流体行为,在其他条件一定时,凉粉草胶的粘度总是随着剪切速度的增大而降低。在剪切速度为40 r/min时,凉粉草胶的粘度随着温度的升高而降低,溶液粘度随着氯化钠添加量的增加而降低,随着糖添加量的增加而增大,随着凉粉草胶质量浓度的增大而变大。     

荠蓝胶流变学特性的研究

研究了荠蓝胶溶液的流变学特性.应用NDJ-1型旋转粘度计和AR550流变仪,考察了浓度、温度、pH、剪切速率、电解质和非电解质对荠蓝胶溶液表观粘度的影响,及其动态流变性质.结果表明,低浓度荠蓝胶具有很高的粘度;荠蓝胶溶液是剪切变稀的假塑性流体,其表观粘度随浓度的增加逐渐增加;随着温度的上升,荠蓝胶溶液的表现粘度下降;pH对荠蓝胶溶液的表观粘度影响很大;盐、蔗糖、柠檬酸在一定浓度范围都会使荠蓝胶溶液表现粘度显著下降.动态流变性质的研究表明,荠蓝胶溶液显示弱凝胶的特性.     

魔芋葡甘聚糖/明胶复配胶液表观粘性研究

该文研究了胶液浓度、pH、剪切速率对魔芋葡甘聚糖及明胶溶液表观粘度影响,并将两者进行复配,研究了pH、复配胶溶液浓度、复配比例对复配胶液表观粘度影响。研究结果表明,魔芋葡甘聚糖和明胶溶液表观粘度随浓度增加而增加;随pH增高呈现出先升后降趋势。魔芋葡甘聚糖溶液表观粘度随剪切速率升高而降低,并表现出了剪切变稀假塑性。明胶溶液表观粘度随剪切速率增加而趋于稳定。复配胶液表观粘度随魔芋葡甘聚糖所占比例增加而增大,随复配胶液浓度变大而变大,随pH增加先升后降;在总胶浓度为2%、魔芋葡甘聚糖与明胶为7∶5的配比、pH=8情况下,复配胶液表现出较好流动性,且形成富有弹性和咀嚼性凝胶体。     

羧甲基沙蒿胶的性质研究

研究了羧甲基沙蒿胶的性质。结果表明,羧甲基化使沙蒿胶的水不溶物含量由原来的56.0%降至15.1%,吸水率为原沙蒿胶的10多倍。羧甲基沙蒿胶溶液的粘度随剪切速率的增加而降低,是假塑性流体,其表观粘度随质量分数的增加而增加。此外,温度、pH值对羧甲基沙蒿胶的粘度影响较小,盐与蔗糖的加入均会改变羧甲基沙蒿胶溶液的粘度。     

茶籽粕多糖流变学性质分析

以研究茶籽粕多糖溶液流变学特性为目的,以分级沉淀和去蛋白后得到的茶籽粕多糖(TSPs80)为对象,采用AR1000流变仪测定了其流变学特性及温度、剪切速率、p H、蔗糖、柠檬酸和金属离子等因素对流变学特性的影响。实验结果表明,TSPs80为假塑性流体,具有触变流体特征。TSPs80的粘度在相同剪切速率条件下与浓度呈正线性相关(p0.05);相同浓度条件下,虽然粘度低于黄原胶,但粘度变化的稳定性随剪切速率变化高于黄原胶(p0.05);25~70℃内,粘度保持高度稳定,而黄原胶则随温度上升粘度迅速下降;粘度随p H升高而升高,随Na+和Ca2+添加量的增加而降低,但变化幅度不大;蔗糖和柠檬酸能显著提高TSPs80粘度(p0.05)。     

沙蒿籽胶的流变学性质研究

研究了沙蒿籽胶的静态流变学特性和动态流变学特性。静态流变学表明:沙蒿籽胶溶液是触变性流体,其表观粘度随质量分数的增加而增加,且随剪切速率变化的影响符合Herschel-Bulkey模型;温度、pH值等对沙蒿籽胶溶液的表观粘度影响较小;盐的加入能改变沙蒿籽胶溶液的粘度。动态流变学特性表明:沙蒿籽胶溶液显示弱凝胶特性。     

亚麻籽胶的流变性质

研究了亚麻籽胶的静态流变性质和动态流变性质.静态流变性质的研究表明:亚麻籽胶溶液是剪切变稀的假塑性流体,其表观粘度随质量分数的增加逐渐增加;温度对亚麻籽胶溶液的表观粘度的影响符合Arrhenius模型,活化能为27.48kJ/mol;pH值对亚麻籽胶溶液的表观粘度影响很大;盐的加入导致亚麻籽胶溶液的粘度降低.动态流变性质的研究表明,亚麻籽胶溶液显示弱凝胶的特性.     

大豆浓缩蛋白溶液表观粘度的研究

本文研究了pH值、温度、NaCl以及SDS对大豆浓缩蛋白(SPC)粘度的影响.结果表明:添加NaCl和提高溶液的pH能使SPC的表观粘度升高,剪切速率的影响增加;添加SDS能降低SPC溶液在低剪切速率时的粘度,剪切速率的影响较小;SPC表观粘度随着温度的升高先是升高后再降低.     

自然发酵对米粉力学性质的影响

通过对整粒大米(籼米)自然发酵，探讨传统自然发酵法对米粉力学性质的影响。研究发现随着发酵时间的增加，米粉的硬度和最大破断应变及塑性呈递增趋势，杨氏模量与最大破断应力随着发酵时间的增加先增加而后减少，屈服强度呈减少趋势。而不同发酵时间、浓度为5％大米粉的糊化流体都属于非牛顿假塑性流体，在相同温度下，剪切应力随剪切速率的增加而增大，表观粘度随剪切速率的增加而减少。发酵7天的大米粉糊化流体的剪切应力和表观粘度在不同温度和剪切速率下都较其他样品大。     

旋转黏度计测马铃薯羧甲基淀粉钠的流变性

以马铃薯淀粉为原料,用溶剂法制备马铃薯羧甲基淀粉钠(CMS),研究马铃薯CMS溶液的流变性。结合马铃薯CMS溶解和糊化温度低的特点,用NDJ-9S旋转黏度计在低温区域(20、30、40、50、60℃)对质量浓度为0.5、1.0、2.0、4.0g/100mL的马铃薯CMS溶液进行测量,得出不同剪切速率时的表观黏度,建立马铃薯CMS流变模型方程,并推断其流变性。将氯化钠、柠檬酸、蔗糖分别添加到质量浓度为4.0g/100mL的马铃薯CMS溶液中,研究氯化钠(1.5g/100mL)、柠檬酸(0.2g/100mL)、蔗糖(5g/100mL)对马铃薯CMS溶液流变性的影响。结果表明:马铃薯CMS为假塑性流体,其表观黏度随温度、质量浓度、剪切速率等条件变化显著。加入蔗糖对马铃薯CMS溶液流变性影响不大,但加入氯化钠和柠檬酸后,溶液的表观黏性和剪切应力下降显著。     

两种皂荚多糖胶流变性质的表征

采用Brookfield 流变仪研究在不同加热时间、温度、pH 值以及盐和糖质量浓度等条件下两种不同形状皂荚豆中多糖胶的流变性质。结果表明：皂荚豆胶是一种假塑性流体,测得的剪切速率和相应的剪切应力的关系符合Power-law 模型,圆皂荚豆胶具有较高的黏度,且假塑性明显高于扁皂荚豆胶。在80℃条件下加热1h 可使皂荚豆胶完全水合,胶液黏度随温度的上升而下降。在pH2～11 范围内,皂荚豆胶比较稳定,但过酸或过碱会导致黏度的下降。皂荚豆胶的黏度随NaCl 质量浓度的上升而下降,随白砂糖质量浓度的上升而略微升高。与扁皂荚豆胶相比,NaCl 对圆皂荚豆胶的降黏作用较为明显。     

Steady-shear flow of semidilute guar gum solutions with sucrose, glucose and sodium chloride at different temperatures

Steady-shear flow curves of aqueous solutions of guar gum at 0.22% at different temperatures (5-65 °C), guar gum (0.22%) with sugars (sucrose or glucose) at different sugar/water ratio (0.10, 0.20 and 0.40) at 5 °C, guar-sugar (at 0.40 sugar/water ratio) at different temperatures (5-65 °C) and guar gum and guar-sucrose (0.40 sucrose/water ratio) with NaCl (1%) at 5 °C, were determined using a controlled-stress rheometer over a wide range of shear rate (1-1000 s⁻¹). Apparent viscosity increased with decreasing temperature and increasing sugar content independent of sugar type. Synergic effect on apparent viscosity due to sugar addition was found and was correlated with sugar content. Salt addition decreased slightly the apparent viscosity and increased the shear-thinning behaviour of the guar gum solution. Steady-shear flow curves were satisfactorily described by the Cross model. Semi-empirical correlations of Cross model parameters with sugar content and temperature were obtained.     

影响沙蒿籽胶表观黏度的因素

利用响应面法和控制变量法分析沙蒿籽胶溶液表观黏度受温度、溶液体积分数、pH值和盐离子的影响变化,同时研究了添加不同比例增稠剂海藻酸钠、魔芋胶、羧甲基纤维素（carboxyl methyl cellulose,CMC）和卡拉胶对沙蒿籽胶溶液表观黏度的影响。结果表明：温度对沙蒿籽胶表观黏度影响不大;随溶液体积分数的增加沙蒿籽胶溶液的表观黏度增加;pH值在3.0～9.0时,沙蒿籽胶溶液表观黏度随pH值的上升而增大;加入盐会使沙蒿籽胶黏度有不同程度的下降,不同阳离子对其黏度影响的强弱为Fe3＋＞Ca2＋＞Mg2＋＞Na＋;沙蒿籽胶与CMC复配后,具有黏度增强的效果。     

Rheological properties of cereal starch gels and Mesona Blumes gum mixtures

The effect of Mesona Blumes gum (MBG) was examined on steady and dynamic shear of MBG/rice starch and MBG/wheat starch gels. In addition, stress relaxation and creep tests were performed for two types of cereal starch gels. The flow curves of both MBG/starch gels exhibited pseudoplastic behavior at shear rates between 0.01 and 10 s⁻¹, and the data were fitted into the power law model (R² = 0.91–0.98). Dynamic mechanical spectrum showed that all gels were strong gels in frequency between 0.1 and 10 Hz. Stress relaxation data at different strains indicated a strain‐softening phenomenon for both gels. Data were fitted into Maxwell model (R² = 0.91–0.98). Creep curves were conducted at the shear stress 6.4 Pa within linear viscoelastic region of both MBG/starch gels. Data were fitted into Burgers model (R² = 0.91–0.98). Apparent viscosity η, storage moduli G′, equilibrium stress relaxation modulus G_e and zero apparent viscosity η₀ of MBG/rice starch gels decreased in the following order: 6/0>6/0.5>6/0.35>6/0.1 (starch/gum w/w). Whereas η, G′, G_e, and η₀ of MBG/wheat starch gels increased gradually along side the increase of MBG contents. The stress relaxation time λ of MBG/rice starch gels increased in the following order: 6/0<6/0.5<6/0.35<6/0.1 (starch/gum w/w) while λ of MBG/wheat starch gels decreased gradually with the increase of MBG level. The influence of MBG on two examined cereal starch is totally opposite.     

低浓度亚麻籽胶的流变特性

对低浓度亚麻籽胶溶液的流变特性进行了研究。结果表明 ,亚麻籽胶溶液属于浓度与粘度关系符合指数规律的流体 ,但当其浓度≤ 3g/L时溶液近似牛顿流体 ,浓度 >3g/L时为假塑性流体 ,且随着浓度增加呈现愈强的假塑性流体特征。亚麻籽胶溶液在一定浓度下表现出剪切稀化的特性。低浓度的亚麻籽胶溶液在pH 6～ 8粘度较大 ,酸、碱均使其粘度降低 ,但酸的影响更大。亚麻籽胶溶液粘度对温度有很强的依赖关系 ,粘度随温度的升高而降低。     

Rheological and thermal effects of galactomannan addition to acorn starch paste

Effect of galactomannans (guar gum and locust bean gum) at different concentrations on rheological and thermal properties of acorn starch pastes was examined. Steady and dynamic shear rheological tests indicated that the magnitudes of consistency index (K), apparent viscosity (η_a,100), Casson yield stress (σ_oc), dynamic moduli (G′, G″), and complex viscosity (η∗) of acorn starch-galactomannan mixtures were much higher than those of the control (0 g/100 g gum concentration), and that these values also increased with an increase in gum concentration. At temperatures ranging from 25 to 70 °C, the effect of temperature on η_a,100 was well described by the Arrhenius equation. In addition, DSC studies showed that the presence of galactomannans resulted in an increase in the transition temperatures (T_o, T_p, and T_c) and a decrease of the gelatinization enthalpy (ΔH). In general, these results suggest that the presence of galactomannans in acorn starch modifies the rheological and thermal properties, but that these modifications are dependent on the gum type and gum concentration.     

亚麻籽胶的溶解特性

通过亚麻籽胶溶液静态和动态流变性质的测定 ,研究了亚麻籽胶的溶解特性。结果表明 ,亚麻籽胶在相同的溶解时间下 ,随着溶解温度的升高 ,亚麻籽胶溶液的表观粘度逐渐增大 ;在相同的溶解温度下 ,随着溶解时间的延长 ,亚麻籽胶溶液的表观粘度逐步增加到最大值后又呈下降趋势 ;在不同的溶解温度下 ,1 %的亚麻籽胶溶液达到最大粘度 1 60 0Pa·s所需时间不同 ,分别为40℃溶解 8h ,5 0℃溶解 6h,60℃溶解 4h ,70℃溶解 4h ,80℃溶解 2h ,而且其粘弹性不同 ,溶解温度越高 ,则凝胶特性越强     

Enhancement effect on apparent viscosity of aqueous tragacanth gum dispersions promoted by sugars

Flow curves of aqueous dispersions of tragacanth gum (T) with sucrose and glucose at different temperatures were determined using a controlled‐stress rheometer. The effect of sodium chloride without or with sucrose (at the highest content) on the rheology of T dispersions was evaluated. The presence of sucrose and glucose promoted a noticeable enhancement impact on the apparent viscosity of aqueous T dispersions, which depended on sugar type/content, shear rate and temperature. In all cases, the glucose addition led to the largest enhanced viscosities at low shear rates (<10 s^?1) and temperature. The joint action of sugar and salt exhibited a notable effect on apparent viscosity at low shear rates, softening the strong shear‐thinning behaviour of T samples. Flow curves of T in the presence of sugars were satisfactorily described by the Cross‐Williamson model, being semi‐empirical correlations of the model parameters with ingredients content and temperature stablished.     

海棠汁的流变特性研究

采用LVDV-III+型流变仪对不同温度、百利糖度下的海棠汁的流变特性进行研究,研究发现海棠汁随着剪切速率增大,表观粘度逐渐增大,剪切应力随之增大;同时随着剪切速率的逐渐增大,表观粘度大小的变化趋势较小但表现出较微的上升趋势。海棠汁流变特性符合胀塑性流体的基本特征,通过Herschel-Bulkley方程拟合,相关系数R2都在0.99以上,并就方程中参数的变化进行了解释说明。     

Studies on the steady shear flow behavior and functional properties of Lepidium perfoliatum seed gum

Flow properties of Lepidium perfoliatum gum, extracted from Qodume shahri seeds, as influences of concentrations (0.5%, 1%, 1.5% and 2%), temperatures (5, 25, 45, and 65 °C), salts and pHs were investigated. Among the selected models, power law model well described the rheological behavior of the L. perfoliatum seed mucilage solutions with high determination coefficients, R² and low root mean square error (RMSE). Non-Newtonian shear thinning behavior was observed at all temperatures and concentrations. While increase in temperature decreased the viscosity and increased the flow behavior indices, adverse effect was obtained by increasing the concentration. The temperature effect was more pronounced at 0.5% L. perfoliatum seed gum concentration and indicated the higher activation energy (E_a: 31614.56 J/mol). The viscosity was dependent on type of salt addition, and decreased with salt concentration. This behavior was more evident when using divalent salt. A marked dependence of viscosity on pH was also observed, as pH increased from acidic to alkaline conditions, the viscosity increased until pH of 9 and afterward decreased. The hydrocolloid showed good water absorption capacity (WAC) and imparted relatively high stability to foam and oil-in-water emulsion. However, the gum solubility was low at all temperatures studied (30, 60 and 90 °C).