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。     

微生物胞外多糖——结冷胶

结冷胶是国内外公认的多功能食品添加剂,阐述结冷胶的结构和特性、生物合成以及在饮料、肉制品、冰淇淋、果冻果酱等食品中的研究情况,并对国内研究开发结冷胶提出了方向。     

结冷胶的特性及其在食品工业中的应用

结冷胶是一种阴离子微生物多糖,具有凝胶形成能力强、透明度高、耐酸耐热性能好等优良特性。在食品加工业中,结冷胶不仅可以作为一种优良的胶凝剂使用,而且能够赋予食品令人愉悦的质地和口感;此外,结冷胶还可与其他食品胶配合使用,广泛应用于面点、糖果、调味品等多种食品加工中,使得食品能够获得最佳的感官、质构和稳定性要求。     

结冷胶LT100流变学特性的研究

研究了结冷胶LT100溶液的凝胶特性及其流变特性,着重研究了结冷胶LT100溶液在不同的浓度、温度、热处理温度、热处理时间、剪切速率、剪切时间、静置时间影响下的流变特性。结果表明:不同浓度的结冷胶LT100形成的凝胶强度有所不同。结冷胶LT100凝胶具有热可逆性、温度滞后性及明显的假塑性。     

结冷胶对猪肉糜凝胶特性的影响

结冷胶作为脂肪替代物可有效降低猪肉糜中的脂肪含量,对增强低脂肉糜制品品质具有良好作用。本试验将结冷胶与水混合制备结冷胶胶体,研究结冷胶胶体替代猪背膘对猪肉糜凝胶特性及品质的影响。结果表明:添加结冷胶胶体显著影响(p<0.05)猪肉糜的蒸煮得率、色泽、质构、流变性和感官特性。结冷胶胶体添加量为0、0.3%和0.5%(质量分数)时,猪肉糜的蒸煮得率和质构差异不显著(p>0.05),0.7%时,蒸煮得率、L*值、硬度、弹性、内聚性和咀嚼性显著降低(p<0.05)。初始储能模量(G')随着结冷胶胶体添加量的增加而降低;结冷胶胶体添加量为0、0.3%和0.5%猪肉糜80 ℃时的G'差异不显著(p>0.05),结冷胶胶体添加量为0.7%时,G'显著下降(p<0.05)。综上所述,结冷胶胶体添加量为0.3%、0.5%时可降低猪肉糜中猪背膘的添加量。     

结冷胶对紫马铃薯饮料特性的影响

通过不同类型稳定剂对紫马铃薯饮料感官指标的影响研究,选择结冷胶作为紫马铃薯饮料的稳定剂,研究了高、低酰基结冷胶对贮藏期内紫马铃薯饮料流变特性、粒径分布、浊度、沉淀率、相分离等特性的影响,结果表明:添加低酰基结冷胶后的紫马铃薯饮料黏度η从0.016 mPa/s增加到1.227 mPa/s;添加高酰基结冷胶的紫马铃薯饮料流变特性更接近原汁,且对贮藏期内饮料的粒径影响不大,而低酰基结冷胶的添加增大了饮料的平均粒径;高酰基结冷胶的添加使紫马铃薯饮料上清液浊度由0.48上升到0.87,而添加低酰基结冷胶的上清液浊度则由0.46下降到0.26;高酰基结冷胶添加量为0.20‰时,饮料在37℃下贮藏15d后色差ΔE*为4.89,与对照组的ΔE*8.96差异显著(P0.05)。当结冷胶添加量超过0.20‰后,饮料的浊度、沉淀率等指标趋于稳定。     

结冷胶对小麦粉及面筋蛋白的影响

将结冷胶按不同比例添加到小麦面粉中,分别考察了结冷胶对小麦面粉粉质特性、拉伸特性、糊化特性的影响。结果表明:结冷胶可以提高面团的吸水率,缩短面团形成时间,提高稳定时间,降低弱化度,且含量越高(300～3 000mg/kg),效果越好;随着结冷胶添加量的增加,拉伸面积、抗拉伸阻力和最大拉伸阻力均呈现增大的趋势。结冷胶对小麦面粉的糊化特性影响不大。同时,进一步考察了结冷胶对小麦面筋蛋白的流变性及微观结构的影响,结果显示:结冷胶可以增加面筋蛋白的黏弹度、韧性及持水性,添加量为600mg/kg的结冷胶便能有效增加面筋的弹性,使面筋网络结构更为连续平滑、孔径变小,孔洞密集且均匀分布。     

NaCl存在下结冷胶以及结冷胶/明胶共混凝胶质构和熔点的研究

研究了不同浓度NaCl(1％～3％,w/v)、结冷胶(0.1 5％～0.35％,w/v)和明胶(1％～3％,w/v)对结冷胶和结冷胶明胶共混凝胶质构特性和熔点的影响.目的是得出结冷胶明胶复配胶凝胶特性,为复配胶在成味食品中的应用提供参考结果表明,共混凝胶硬度和熔点随NaCl浓度增加而增大,当NaCl浓度高于1.5％时,硬度和熔点均下降;结冷胶和明胶浓度对共混凝胶硬度影响较大;结冷胶形成的凝胶弹性差,与明胶复配使用,弹性显著提高,并且共混凝胶弹性随结冷胶浓度增大而降低,随明胶浓度增大而增大;结冷胶浓度决定了共混凝胶的熔点结冷胶和明胶复配可以弥补各自单独使用的不足,且复配胶兼具高熔点和入口即化的特性.     

结冷胶溶液凝胶特性的研究

结冷胶是一种新型食品添加剂。其存在形式为天然式和低酰基式。天然式结冷胶溶液的凝胶特性是粘弹性体,低酰基结冷胶溶液是凝胶体。将两种形式的结冷胶溶液在相同条件下与卡拉胶、琼脂溶液进行了比较,得出两种形式的结冷胶溶液在0.05％时可形成凝胶,大大低于卡拉胶和琼脂的成凝胶浓度。     

高酰基结冷胶(HA)特性的研究进展

高酰基结冷胶是美国Kelco公司开发的一种新型微生物多糖,它是由少动鞘脂单胞菌（Sphingomonas paucimobilis）经有氧发酵产生的。高酰基结冷胶是集凝胶剂、稳定剂、悬浮剂于一身的多功能亲水性胶体,具有热可逆性、高持水性、良好的复配性等优良特性,因此在食品工业中逐步展现广阔的应用前景。本文综述了高酰基结冷胶的结构、凝胶机理及其特性,并对其应用前景作了探讨。     

结冷胶凝胶特性及在食品工业中的应用

目的:介绍新型微生物多糖--结冷胶的凝胶特性及其在食品工业中的应用现状和前景.方法:查阅今年来国内外的相关文献报道,并进行分析、整理和归纳.结果:结冷胶组织相容性和复配性能良好,具有良好的透明性,凝胶性能卓越,具有独特的胶凝和融化温度,可形成多种凝胶质构,在极低的用量下形成的预(弱)凝胶可以发挥良好的悬浮、稳定作用.结论:结冷胶作为一种新型凝胶剂,其优异的性能将在食品工业中得到广泛应用.     

响应面法优化复合植物蛋白饮品的稳定体系

用响应面方法对复合植物蛋白饮品的稳定体系进行了优化。先用全因子实验对稳定剂组分卡拉胶、瓜尔豆胶、黄原胶和结冷胶对复合植物蛋白饮品沉淀量的影响进行了评价,并找出主要影响因子为瓜尔豆胶和结冷胶,其它组分对沉淀量没有显著影响。采用中心组合设计及响应面分析确定主要影响因子的最佳浓度。稳定体系的最佳组成为(g/L):卡拉胶0.2、瓜尔豆胶0.5、黄原胶0.2、结冷胶0.5,此条件下复合植物蛋白饮品表现出良好的稳定性。     

微生物多糖结冷胶的发酵过程优化

利用玉米浆和尿素作为廉价氮源进行结冷胶的发酵生产,通过对发酵过程中的初糖浓度、通气量和搅拌转速进行优化,获得具有生产成本优势的新工艺。结果表明:结冷胶发酵的最佳初糖浓度和通气量分别为40g/L和1 vvm;最佳的搅拌转速控制策略为延滞期(0～12 h)400 r/min,对数期(12～32 h)800 r/min,稳定期(32～40 h)400 r/min。在上述条件下,结冷胶产量、黏均分子量和发酵液表观黏度分别为16.7 g/L、625.8 kDa和7495 cP。     

NEW PARAMETERS FOR INSTRUMENTAL TEXTURE PROFILE ANALYSIS: INSTANTANEOUS AND RETARDED RECOVERABLE SPRINGINESS

Cylindrical samples of gelatin, K-carrageenan/locust bean gum and gellan gum gels were subjected to two successive cycles of compression at three predetermined deformation levels corresponding to 25, 50 and 75% of their respective degrees of compression at failure. Values of "recoverable instantaneous springiness" (S_ins) and "recoverable retarded springiness" (S_ret) were measured. Values of S_ins and S_ret for the gelatin samples were similar and close to 1, indicating a very fast and almost complete recovery of their initial height. By contrast, for K-carrageenan/locust bean gum and gellan gels the values of S_ins and S_ret were quite different, indicating that recovery was retarded. These parameters seem to be a good index of the relative magnitude of elastic and viscous components of foods. This was confirmed by relaxation tests.     

Determination of gellan gum by capillary electrophoresis and CE–MS

Intact gellan gum (0.1% m/v) was detectable by capillary electrophoresis (CE) with UV detection. Characteristic tetrasaccharide fragments, prepared with a newly characterised gellan-degrading enzyme, provided a clearer signal that was detectable in complex food products containing other polysaccharides. Food products spiked with gellan gum could be analysed reproducibly with high accuracy and specificity by CE–ESI–MS, which is recommended as the technique of choice. Gellan gum declared as a fruit flavour drink ingredient could not be identified by CE–ESI–MS. When added to the product at the start of sample preparation, before enzyme treatment, the gum was readily detectable, demonstrating that the method was compatible with this sample type. Possible explanations for the negative results are that gellan gum was used as a trace component, with other texturing agents; that its declaration was precautionary only; or that the product contained a chemically modified form. Further work will establish whether modified gellan gums can be similarly analysed.     

明列子饮料悬浮剂的研究和应用

以琼脂、果胶、卡拉胶和结冷胶等8种胶体各作为复配型悬浮剂主剂研制开发悬浮剂，并将其应用于明列子悬浮饮料中。经大量的实验表明，以卡拉胶或结冷胶为主剂，并与适当的电解质、其胶体复配而成的悬浮剂的性能良好，悬浮效果较为理想，从而本实验为它们在悬浮饲料中的生产应用提供了实验依据。     

结冷胶发酵液微滤除菌工艺

采用有机微滤膜对结冷胶发酵液进行过滤除菌实验。考察了不同膜材料的过滤性能,以及结冷胶浓度、温度、压力等操作参数对除菌效果的影响。将结冷胶发酵液脱酰基处理后稀释成浓度为3 g/L的料液,再将酸碱度调至pH10,在0.1 MPa、65℃下用孔径为0.45μm的聚醚砜膜过滤,菌体去除率和结冷胶回收率分别为97%和84%。滤膜污染后采用0.75%HCl和1%NaOH交替清洗,可使膜通量得到较好地恢复。     

基于组分调控的胶原蛋白肠衣凝胶糖果物性及感官品质

为了考察组分对胶原蛋白肠衣凝胶糖果物性及感官品质的影响,分别以显微结构、色差分析、物性分析、感官品质分析为手段,探究糖馅中高、低酰基结冷胶及蔗糖、果葡糖浆的最佳用量。结果表明,低酰基结冷胶用量与凝胶糖果的紧实程度、硬度和回弹力呈正相关,与顺滑感、融化性和润湿性呈负相关;高酰基结冷胶用量与贴合程度呈正相关。最终获得消费者喜爱的胶原蛋白肠衣凝胶糖果糖馅中各物质质量分数为：去离子水150%、果葡糖浆80%、蔗糖20%、低酰基结冷胶1.5%、高酰基结冷胶1.5%、乳酸钙1.0%、柠檬酸钠0.25%。     

Gellan gum for reducing oil uptake in sev,a legume based product during deep-fat frying

Gellan gum, a high molecular weight anionic linear polysaccharide produced by pure culture fermentation from Sphingomonas paucimobilis ATCC 31461 is used in a variety of food applications that are based on its unique gelling profile. The present work reports on the effective use of gellan gum on the oil uptake of a traditional Indian deep-fat fried product, sev that is based on chickpea flour. The effect of addition of gellan gum at 0.25–0.75% (w/w) (based on chickpea flour) on the dough texture, and that of the sev prepared was also evaluated using TA.XT2i Texture Analyzer. Addition of gellan gum at 0.25% (w/w) markedly reduced the oil content in the sev from 37.02% in the control to 27.91%. The reduction in oil content beyond 0.25% gellan gum addition was not significant (P = 0.05). Furthermore, while addition of gellan gum significantly altered the texture of dough, it did not significantly affect the texture of sev (P = 0.05). Addition of 0.25% gellan gum in combination with sodium alginate (0.25–1.00%), carboxymethylcellulose (0.25–1.00%) or soy protein isolate (2.5–10.0%) did not affect oil uptake significantly (P = 0.05) as compared to that prepared by the addition of 0.25% gellan gum alone.