结冷胶-羧甲基纤维素复配胶性能的研究

利用全质构分析、离心分离和分光光度法研究了结冷胶-羧甲基纤维素（carboxyl methyl cellulose,CMC）的配比、离子种类和离子浓度对结冷胶-CMC复配胶质构、持水力以及透明度的影响。结果表明：复配胶硬度随结冷胶比例降低而降低;在离子浓度达到临界水平前随离子浓度增加而增加,临界水平之后随离子浓度增加而降低;添加钙离子比钠离子更容易得到高硬度的凝胶。总的来说,添加离子会降低凝胶的弹性和内聚性;适当的结冷胶和CMC比例可提高凝胶弹性和内聚性。降低结冷胶-CMC复配比例可提高复配胶的透明度。     

鳕鱼皮胶液的凝胶特性及其结冷胶的改善作用

研究了鳕鱼皮胶液的凝胶特性及其结冷胶的改善作用。目的是为鳕鱼皮凝冻产品的开发利用提供参考。结果表明,鳕鱼皮胶液的凝胶温度低、稳定性差,仅添加结冷胶对其凝胶特性并无改善作用;而同时添加结冷胶和氯化钠可明显改善鳕鱼皮胶液的凝胶特性,且随着结冷胶浓度的增加,鳕鱼皮胶液的凝胶硬度和凝胶温度明显提高,脱水收缩率明显降低;当鳕鱼皮胶液浓度为3%(w/w,以胶原蛋白含量计),结冷胶浓度为0.2%(w/w),氯化钠浓度为0.75%(w/w)时,鳕鱼皮胶液的凝胶特性最佳。     

低质量分数结冷胶的流变性质

以低质量分数(0.01%～0.25%)结冷胶(gellangum)为研究对象,研究了结冷胶溶胶(质量分数为0.01%～0.04%)的流变性质,考察了Ca2+质量分数及胶质量分数对结冷胶凝胶(0.05%～0.25%)的凝胶强度的影响以及Ca2+与K+在促进凝胶的协同作用.结果表明,质量分数为0.01%～0.04%的结冷胶溶胶的流变学类型接近Cross模型,该体系具有剪切稀化性、触变性及屈服应力,且三者均随结冷胶质量分数的增大而增大.动态测量结果表明,上述溶胶是以弹性为主的粘弹性体系,弹性所占比例随结冷胶质量分数的增大而增大.结冷胶凝胶(质量分数为0.05%～0.25%)的凝胶强度随胶质量分数的增大而增大;随Ca2+质量分数的增大呈先增大后减小的变化规律,Ca2+的最适用量为200～280mg/kg.Ca2+与K+对促进结冷胶凝胶无协同作用.     

高酰基结冷胶/酪蛋白酸钠复合凝胶粘弹行为的研究

本文研究了酪蛋白酸钠浓度、结冷胶浓度、离子和测试条件对高酰基结冷胶/酪蛋白酸钠复合凝胶粘弹性的影响。结果表明:高酰基结冷胶/酪蛋白酸钠共混体系为典型的切力变稀流体,表观粘度随着酪蛋白酸钠浓度的升高而降低,而随着阳离子浓度的增大出现先增大后减小的变化趋势。压缩速度对复合凝胶硬度几乎无影响,而内聚性和弹性则随着压缩速度的增加而增大。内聚性随着压缩应变的增大出现先增大后减小的变化趋势。复合凝胶的硬度和弹性随着酪蛋白酸钠浓度的增加而下降,但复合凝胶的内聚性对酪蛋白酸钠浓度不敏感。高酰基结冷胶浓度越高,复合凝胶的硬度和弹性越大。相对于一价离子而言,二价离子形成的凝胶更强且用量更少。钾离子的添加对复合凝胶保水性影响较弱,而钙离子的添加则可以提高复合凝胶的保水性。     

钙盐和明胶对高酰基结冷胶的凝胶特性的影响

利用质构仪质构剖面分析法（TPA）研究了不同浓度的氯化钙、乳酸钙、葡萄糖酸钙对高酰基结冷胶凝胶特性的影响；明胶添加量对高酰基结冷胶凝胶特性的影响；以及三种钙盐和明胶对高酰基结冷胶凝胶特性的影响。结果表明，三种钙盐都可以提高高酰基结冷胶的凝胶强度。添加明胶可以提高高酰基结冷胶的凝胶强度、咀嚼性、弹性和内聚性。对比三种钙盐，添加乳酸钙的高酰基结冷胶-明胶复配胶凝胶特性最好。因此，适量的钙盐和明胶可以提高高酰基结冷胶的凝胶特性，为高酰基结冷胶在食品中的应用提供理论参考。     

银耳多糖与结冷胶复配体系的流变及凝胶特性

对不同质量浓度的银耳多糖溶液、结冷胶溶液（均为0.4、0.8、1.2、1.6、2.0 g/100 mL）及不同质量比（1.6∶0.4、1.2∶0.8、0.8∶1.2、0.4∶1.6）的银耳多糖/结冷胶复配体系的流变和凝胶特性进行研究,初步探讨其相互作用机理。结果表明,随着银耳多糖质量比的提高,复配体系的表观黏度和动态黏弹性增加,储能模量（G’）和损耗模量（G”）增加。复配体系的触变环随银耳多糖质量比例的增加而减小,说明银耳多糖可以改善复配体系的触变性。质构分析和持水性测试结果表明,结冷胶是银耳多糖/结冷胶复配凝胶强度和硬度的决定性因素,银耳多糖可以明显提高复配体系的弹性、黏性和持水性。基于傅里叶变换红外光谱和低温扫描电子显微镜分析,初步判断在复配体系中银耳多糖与结冷胶之间存在相互作用,形成了凝胶网络结构。     

高酰基结冷胶与κ-卡拉胶复配胶的质构特性研究

用抗压实验和全质构测试对高酰基结冷胶(HA)与κ-卡拉胶(CA)复配胶的凝胶强度、形变性以及硬度进行分析。研究了Ca2+、Mg2+、K+、Na+四种离子以及HA与CA的质量比对复配胶质构特性的影响。实验中,总胶浓度控制为1%(w/v),离子浓度为2～80mmol/L,HA和CA的质量比为25:75、50:50、75:25。结果表明,二价离子较一价离子作用效果显著,其中Ca2+效果最为显著,复配胶在HA:CA=75:25时有显著的协同作用,HA与CA的复配胶有着较强的形变性。     

结冷胶与卡拉胶/魔芋胶的复配机理研究

本文主要研究了不同KC、lNaCl浓度对结冷胶、κ-卡拉胶、魔芋胶复配体系凝胶强度的影响。实验结果显示:在一定浓度范围内,KCl使结冷胶与卡拉胶复配体系的凝胶强度基本为两者单体自身的凝胶强度之和,而NaCl则使两者具有一定的协同作用。魔芋胶与卡拉胶的协同作用是建立在卡拉胶先形成有序结构的基础上。通过对实验结果的分析,提出了结冷胶与卡拉胶/魔芋胶复配体系可能的凝胶协同机理。     

高酰基结冷胶的溶胶和凝胶特性研究及结构初步分析

采用黏度计和质构仪对高酰基结冷胶的溶胶和凝胶性质进行研究。结果表明：高酰基结冷胶在质量浓度为 0.05～0.1g/100mL 时,表观黏度随质量浓度增加而增加,并呈现假塑性流体特性;在质量浓度为0.2～0.5g/100mL时形成凝胶,凝胶强度受胶体及 Ca2+ 质量浓度的影响明显,同时高酰基结冷胶比例增加,高低复配胶体的凝胶强度减小。并利用红外光谱扫描和核磁共振技术对高酰基结冷胶结构进行初步分析。     

κ-卡拉胶/明胶复配胶对牛奶布丁凝胶性质的影响

蛋白质-亲水胶体混合物的凝胶特性对食品的质地和稳定性有着重要影响。论文重点研究了κ-卡拉胶/明胶复配胶浓度对牛奶布丁凝胶强度、质构特性、水分分布和微观结构等特性的影响。结果表明：随K-G复配胶浓度的增加,体系中凝胶强度、硬度、咀嚼性、内聚性和回复性均显著增大,黏性和弹性变化不显著;牛奶布丁体系中以不易流动水为主,单组分弛豫时间(T_2W)及不易流动水弛豫时间(T₂₂)随K-G复配胶浓度增加而略微增加,当K-G复配胶浓度在0.6%以上时,水分比例(S₂₁、S₂₂、S₂₃)结构相对稳定。微观结构结果表明,K-G复配胶浓度的增加有助于牛奶布丁凝胶体系趋于均一、致密。总体而言,添加0.6%的κ-卡拉胶/明胶的复配胶有助于牛奶布丁的制备。     

Mechanical and physical properties of calcium-treated gellan films

The physicochemical properties of Ca²⁺-treated gellan films plasticized with glycerol were investigated as a function of CaCl₂ concentration (0–20%, w/w) in an aqueous soaking solution. Films were examined based on their mechanical properties, water vapor permeability (WVP), swelling index (SI), thickness and opacity. The SI was lower for Ca²⁺-treated films relative to a control, however, above 13% (w/w) CaCl₂ no differences in SI were found. At 13% (w/w) CaCl₂, tensile and puncture strengths reached a maximum. Tensile elongation, puncture deformation, film thickness and WVP were lower for CaCl₂-treated films than untreated, however, all increased with CaCl₂ concentration. Opacity of gellan films increased with the Ca²⁺-treatment relative to the untreated film, however declined as CaCl₂ concentration increased. In general, Ca²⁺-treated gellan films were stronger, acted as better water vapor barriers, swelled less when in contact with water, and became less pliable and transparent.     

结冷胶的成胶特性及应用研究进展

本文综述了结冷胶的凝胶特性，凝胶机制和流变学特性，对结冷胶的凝胶原理、显微结构也进行了阐述。并介绍了结冷胶复配体系的特点及其应用前景。     

结冷胶生物合成及应用

结冷胶是由少动鞘脂单胞菌产生的一种新型微生物多糖,具有用量低、透明度高、耐酸、耐高温、耐酶、兼容性好等优良特性,在食品、制药、化工等行业具有广泛的用途。通过介绍结冷胶理化方面的特性,总结了结冷胶发酵生产工艺,以及提高产量和质量的关键因素,进一步展望了未来结冷胶的发展趋势和应用前景。     

Texture and structure of high-pressure-frozen gellan gum gel

To determine the effects of sucrose and high-pressure-freezing, unsubstituted form-gellan gum gels with 0, 5, 10 or 20% sucrose were frozen at 0.1–686 MPa and −20 °C. Gels were frozen during pressurization at 0.1, 100, 600–686 MPa. However, at 200–500 MPa, gels did not freeze but froze during pressure release (pressure-shift-freezing). On pressure release, a sharp rise in sample temperature was observed for the samples between 200 and 500 MPa. This was a consequence of the exothermic freezing event. Thus, appearance and structure of gels frozen at 200–500 MPa were better than other treated samples due to quick freezing. However, when gels were frozen at 0.1–686 MPa, rupture stress decreased remarkably and strain increased. Texture of pressure-shift-frozen gel was somewhat better than that of gels frozen in freezers (−20, −30 or −80 °C) at atmospheric pressure. Consequently pressure-shift-freezing was more effective. It was found that the addition of sucrose to gels was effective in improving the quality of frozen gellan gum gels.     

Characterization of gellan/gelatin mixed solutions and gels

The physico-chemical properties of gellan/gelatin mixed solutions and gels were examined at five different ratios of gellan to gelatin (100:0 (I), 80:20 (II), 60:40 (III), 40:60 (IV), 20:80 (V)) and four different NaCl levels (0–300 mmol/l). All mixed solutions exhibited the shear-thinning behavior, which decreased with increasing gelatin proportion, temperature, and NaCl level. Synergism on G′ was observed in mixed solution III and IV depending on NaCl level. Hardness of mixed gel decreased with increasing gelatin proportion and cohesiveness increased up to the gellan to gelatin ratio of 40–60 and then decreased. For gellan dominant gels, maximum hardness and cohesiveness were observed at NaCl level of 150 mmol/l. Increasing gelatin proportion caused an increase in gel turbidity at lower NaCl levels and a decrease in gel turbidity at higher NaCl levels. In general, WHC increased with increasing gelatin proportion and decreasing NaCl level. Color holding capacity significantly increased with increasing gelatin proportion. Flavor holding capacity increased by adding gelatin and then linearly decreased with increasing gelatin proportion. Therefore, this study suggests that there is an optimum NaCl concentration and gellan to gelatin ratio to enhance the physico-chemical properties of gellan/gelatin mixed solutions and gels.     

结冷胶-茶多酚复合膜性能的研究

以结冷胶为成膜材料,甘油为增塑剂,添加不同比例的茶多酚(1、2、3、4、5 g/L)制成可食用膜以增强抑菌作用。结冷胶-茶多酚复合膜液的静态和动态流变学性质研究发现结冷胶-茶多酚复合膜膜液具有剪切变稀的现象,表观黏度、储能模量G'和损耗模量G″均随着茶多酚浓度的增加而增加。茶多酚的加入可提高复合膜拉伸强度和阻氧性,但降低了复合膜的断裂伸长率,同时也提高了复合膜的阻水性能。与未加茶多酚的结冷胶膜相比,复合膜具有抑制枯草芽孢杆菌、大肠杆菌、产黄青霉和酿酒酵母的性能。研究结果可为食品活性包装膜的研发提供一定的理论依据。     

低酰基结冷胶流变行为研究

研究了浓度、温度、剪切速率、pH和离子浓度对低酰基结冷胶流变行为的影响。结果表明,低酰基结冷胶为典型的切力变稀流体,其表观黏度和剪切速率的关系符合幂律方程。在同一剪切速率下,表观黏度随温度的升高而降低。在同一温度下,结冷胶溶液的表观黏度则随着剪切速率的增加而减小。低酰基结冷胶凝胶强度随着Ca2+和Na+浓度的增加出现先增大后减小的趋势,相对于Na+而言,Ca2+形成的凝胶强度更高,且用量更少。     

结冷胶研究进展

结冷胶是一种微生物胞外多糖。由于其高效,无毒,耐高温等特点被广泛用于食品,医药,化工等行业。着重介绍其结构,物理化学性质,发酵培养基成分,发酵工艺条件,提纯方法和生产现状。培养基成分中介绍碳源,氮源,无机盐对发酵的影响。发酵工艺中介绍了温度,pH,接种时间,接种量,搅拌速度和通气量对发酵的影响。     

结冷胶在果冻、果酱等食品中的应用

阐述了结冷胶的结构和特性,结冷胶水溶液在低浓度0.01%～0.04%的范围内呈假塑性流体特性,在0.05%时即可形成凝胶,与其它食品胶复合可应用于果冻、果酱、人造食品(类果肉)、饼馅和布丁等食品生产中。     

结冷胶发酵生产工艺研究

通过新型制备菌种等原料发酵制备结冷胶。研究通过单因素实验和正交试验,以发酵所得结冷胶的黏度和产胶率为指标,对发酵时间、接种时间、装液量、接种量、温度、pH、摇床转速等条件进行优化。结果表明:优发酵时间为60h,接种时间为20h,装液量为10%,接种量为10%,温度为30℃,pH为7.2,摇床转速为220rpm时产胶率达到1.41%。为工业化发酵制备结冷胶,提高产胶率提供参考。