不同影响因素对三元食品胶溶液粘度的影响

利用德国HAAKE公司生产RS75应力控制流变仪,考察了改变pH、添加蔗糖、氯化钠和柠檬酸钠、进行冻融处理、添加大豆多肽等因素,对三元混合胶(卡拉胶∶魔芋胶∶刺槐豆胶为2∶2∶1)溶液粘度的影响。结果表明,在强酸、强碱条件下,溶液粘度均有所下降,但是碱性条件下胶体溶液的粘度相对稳定;在一定范围内蔗糖、氯化钠和柠檬酸钠均能降低胶体溶液的粘度,而两种钠盐降低胶液粘度的幅度较大;无论是冷冻处理还是冷藏处理都可降低胶体溶液的粘度;大豆多肽的加入也会在一定程度上降低混合胶溶液的粘度,改变加料方式可以减小这种影响。     

魔芋胶对甘薯淀粉流变学特性及粉条品质的影响

研究多糖胶对淀粉糊化特性、老化特性、流变学特性及粉条食用品质的影响,为改善粉条品质提供理论指导。该文选择甘薯淀粉为原料,加入不同比例的魔芋胶,通过快速粘度仪(RVA)测定淀粉与魔芋胶复配体系粘度的变化来考察体系的糊化特性;用X衍射仪测定结晶度,评价体系的长期回生情况;通过流变仪考察魔芋胶对淀粉凝胶体系粘弹性的影响;最后评价魔芋胶对粉条食用品质的改善效果。结果表明:魔芋胶能够显著降低甘薯淀粉的糊化温度,提高粘度、崩解值和回生值,显著抑制淀粉的长期回生。甘薯淀粉/魔芋胶复配体系为屈服-假塑性流体,并且随着魔芋胶添加量的增加,屈服应力τ0、稠度系数K增加,流体指数n减小,复配体系有更好的粘弹性。甘薯淀粉和魔芋胶按质量比为8.5:1.5制备的粉条食用品质最佳。     

羧甲基纤维素与魔芋葡苷聚糖复配溶胶研究

通过单因素和L9(34)正交实验研究了羧甲基纤维素(CMC)与魔芋葡苷聚糖(KGM)的复配比例、搅拌时间、温度、p H及放置时间等因素对CMC/KGM复配溶胶粘度的影响。结果表明:CMC与KGM复配具有协同增稠效应;随着放置时间的延长,CMC与KGM复配溶胶粘度的稳定性优于单体KGM溶胶;CMC与KGM复配溶胶的最佳制备条件:CMC与KGM的质量比为2∶8(复配溶胶的总浓度为10g/L),搅拌时间为4h,温度为30℃,p H为7,其粘度值为38063m Pa·s。     

四种变性淀粉与黄原胶和魔芋胶复配体系粘度特性研究

目前对变性淀粉与黄原胶和魔芋胶复配体系粘度特性以及其抗酸和抗剪切方面的研究尚鲜见报道。本研究以变性淀粉:木薯羟丙基二淀粉磷酸酯(HDP-CS)、木薯乙酰化二淀粉磷酸酯(ADP-CS)、马铃薯乙酰化二淀粉磷酸酯(ADP-PS)、马铃薯乙酰化双淀粉己二酸酯(ADA-PS)分别与黄原胶(XG)、魔芋胶(KG)进行复配,以粘度为考察指标,测定复配体系的抗剪切性和抗酸性,筛选最佳组合。在各配比浓度的基础上,分析两者复配体系的特性,通过对其协效性、回归方程和显著性进行分析确定最佳配比浓度。结果表明:通过对抗剪切性和抗酸性的测定结果分析,最佳复配体系为:马铃薯乙酰化二淀粉磷酸酯—黄原胶和木薯羟丙基二淀粉磷酸酯—魔芋胶复配体系;前者复配体系随变性淀粉浓度的变化而呈线性变化,后者呈指数变化。两复配体系的最佳配比浓度为:ADP-CS:XG=2%:0.4%(g/g);HDP-CS:KG=2.5%:0.4%(g/g),此研究结果比前人研究有所改善。     

魔芋葡甘露聚糖与木薯淀粉复配溶胶及协效性研究

以魔芋葡甘露聚糖(konjac glucomannan,KGM)和木薯淀粉(cassava starch,CS)为原料进行复配研究,探讨魔芋葡甘露聚糖/木薯淀粉复配溶胶的复配协同增效性,研究多糖总浓度、复配比例、温度和p H对复配溶胶粘度和透光率的影响。结果表明:KGM与CS复配,可产生协同增效性,复配溶胶的粘度大于两者之和;KGM/CS复配溶胶的最佳条件:多糖的总浓度3.0%,KGM/CS比值为3∶7,溶胀温度80℃,pH7,最优条件下的KGM/CS复配溶胶的粘度为41.391×10~3c P,透光率为7.339%。     

κ-卡拉胶与魔芋胶复配胶体系的流变特性

研究κ-卡拉胶与魔芋胶(质量比为5.5:4.5)复配胶的流变特性,考察温度、电解质等对复配胶流变特性的影响。结果表明:30℃时复配胶的储能模量G'高于κ-卡拉胶和魔芋胶单体胶的储能模量G',其损耗模量G低于κ-卡拉胶的损耗模量G,复配胶的凝胶性质更加明显。随着温度的升高,复配胶体系的G'始终大于G,具有典型黏弹性流体的特性。加入0.1g/100mL KCl和CaCl2均能使复配胶体系的G'下降,使复配胶溶胶转化温度提高,但KCl的影响更明显。     

κ-卡拉胶与魔芋胶复配胶的流变性能及其微观结构研究

研究κ-卡拉胶与魔芋胶(质量比为5.5:4.5)复配胶的流变特性,考察剪切速率、振动频率和温度等对复配胶流变特性的影响。研究结果表明:30℃时复配胶的储能模量G′高于κ-卡拉胶和魔芋胶单体胶的储能模量G′,其损耗模量G"低于κ-卡拉胶的损耗模量G",复配胶的凝胶性质更加明显。随着温度的升高,复配胶体系的G′始终大于G",具有典型黏弹性流体的特性。结构分析表明κ-卡拉胶与魔芋胶之间具有较好的协同作用,通过分子间氢键形成了以κ-卡拉胶网络结构为主,魔芋胶穿插其中的交联网络体系。     

κ-卡拉胶与刺槐豆胶复配胶的流变学特性研究

本文分析了不同配比、浓度、pH和不同阳离子对κ-卡拉胶与刺槐豆胶复配胶粘度的影响,在此基础上研究了κ-卡拉胶与刺槐豆胶(质量比为6∶4)复配胶的静态和动态流变学特性,以及温度对粘弹性的影响。结果表明:复配胶的质量比为6∶4时存在协同增效作用,粘度最高;浓度和pH都对粘度有所影响;不同阳离子都会使复配胶的粘度降低,但KCl对粘度的影响最小。根据剪切速率与粘度的变化规律可以发现,κ-卡拉胶与刺槐豆胶复配后抗剪切能力增强。一定温度范围内,复配胶的储能模量高于单体胶的储能模量,而复配胶的损耗模量低于单体胶损耗模量,这表明复配胶的凝胶性质较两种单体胶更加明显。随着温度的升高,在65℃时损耗模量大于耗能模量,体系由凝胶状化向溶胶状态转换,确定了复配胶的融化点为65℃,这为今后的植物胶囊的制备提供了可靠理论依据。     

魔芋胶对莲藕淀粉糊化和流变特性的影响

为考察亲水性胶体对淀粉性质的影响,以莲藕淀粉为原料,加入不同比例的魔芋胶,研究两者复配后莲藕淀粉的糊化、流变、质构特性及微观结构的变化。结果表明,魔芋胶提高了莲藕淀粉的黏度、回生值、崩解值,降低了糊化温度。莲藕淀粉/魔芋胶复配体系为假塑性流体,并且随着魔芋胶添加量的增加,稠度系数K增加,流体指数n减小,复配体系有更好的增稠性;魔芋胶的加入使体系黏性比例提高,具有优越的黏弹性;同时加速了莲藕淀粉凝胶体系的回生。淀粉复配体系的硬度、弹性、内聚性降低,黏着性升高,其中莲藕淀粉与魔芋胶质量配比为8.5∶1.5时,形成的凝胶质地最柔软。同时通过扫描电镜观察到魔芋胶的添加使淀粉内部形成更加均匀紧凑的网络结构。     

食品增稠剂瓜儿豆胶性质及复配性的研究

本文对瓜尔豆胶的流变性,浓度、温度、pH值、电介质对粘度的影响,与黄原胶、卡拉胶复后粘度变化进行了初步研究。结果表明,低浓度瓜儿豆胶属非牛顿流体中假塑性流体,其粘度随浓度升高而上升,随温度升高而下降,几乎不受pH值影响,对NaCl和低浓度Ca~(2+),Al~(3+)有良好兼容性,与卡拉胶复配无增效作用,而与黄原胶复配增效显著,复配最佳比例为瓜儿豆胶:黄原胶=0.6:0.4     

Viscosity of guar gum and xanthan/guar gum mixture solutions

The viscosity of diluted guar gum solutions and the viscosity of xanthan and guar gum mixture solutions have been studied. Guar gum solutions showed pseudoplastic behaviour. Apparent viscosity increased with gum concentration and decreased with the temperature at which viscosity was measured. A maximum in the plot of viscosity versus increasing dissolution temperature was observed at 60 °C. This behaviour was related to differences in molecular structure of the polymers solved at different temperatures. Mixtures of xanthan and guar gum showed a higher combined viscosity than that occurring in each separate gum. This synergistic interaction was affected by the gum ratio in the mixture and dissolution temperature of both gums. The effect of polysaccharide concentration (1.0, 1.5 and 2.0 kg m⁻³), xanthan/guar gum ratio (1/5, 4/2, 3/3, 4/2 and 5/1) and dissolution temperature (25, 40, 60 and 80 °C for both gums) on the viscosity of solutions of mixtures were studied. The highest viscosities were observed when 2.0 kg m⁻³ gum concentration was used together with a ratio of xanthan/guar gum of 3/3 (w/w) and dissolution temperature of 40 and 80 °C for xanthan and guar gum, respectively. © 2000 Society of Chemical Industry     

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。     

Viscosity of solutions of xanthan/locust bean gum mixtures

Xanthan and locust bean gums are polysaccharides able to produce aqueous solutions with high viscosity and non‐Newtonian behaviour. When these solutions are mixed a dramatic increase on viscosity is observed, much greater than the combined viscosity of the separated polysaccharide solutions. In this work the influences of different variables on the viscosity of solutions of mixtures of xanthan/locust bean gum have been studied. Total polysaccharide concentration, xanthan and locust bean ratio on mixture and temperature at which the gum was dissolved (dissolution temperature) for both xanthan and locust bean gums have been considered. Under these different operational mixture conditions shear rate and time have also been considered to describe the rheological behaviour of the solutions studied. The high viscosity increase observed in these mixtures is due to the interaction between xanthan gum and locust bean gum molecules. This interaction takes place between the side chains of xanthan and the backbone of the locust bean gum. Both xanthan molecule conformation in solution – tertiary structure – and locust bean gum structure show great influence on the final viscosity of the solution mixtures. Xanthan conformation changes with temperature, going from ordered structures to disordered or chaotic ones. Locust bean gum composition changes with dissolution temperature, showing a dissolved galactose/mannose ratio reduction when temperature increases, ie the smooth regions – zones without galactose radicals – are predominantly dissolved. The highest viscosity was obtained for the solution mixture with a total polysaccharide concentration of 1.5 kg m⁻³ and a xanthan/locust ratio of 2:4 (w/w) and when xanthan gum and locust bean gum were dissolved at 40°C and 80°C, respectively. © 1999 Society of Chemical Industry     

Rheology and modelling of aqueous gum solutions commonly used in the food industry

Rheological properties of solutions prepared using xanthan (XG), locust bean (LBG) or sodium carboxymethyl cellulose (CMC) gums, and their binary mixtures were studied. The influence of shear rate, total gum content, measurement time and temperature on the apparent viscosity was investigated. In the binary mixtures, the presence of different gum ratios at several total gum content was also analysed. XG solutions were always the most stable, providing high viscosity values which rose notably with increasing gum content. XG/LBG and CMC/XG mixtures depicted high values of viscosity for very low gum amounts. Viscosity did not change with measurement time in mixtures containing XG, whereas varied with measurement temperature. This variation was lower for samples with larger total gum content. The viscosity was also modified when different gum ratios were tested. A mathematical model was proposed to evaluate the combined effect of temperature, concentration and shear rate on the apparent viscosity.     

盐及非盐物质对常用低浓度食品胶溶液粘度影响的研究

对饮料生产中常用的食品胶－黄原胶、海藻酸钠、瓜尔胶和琼脂在低浓度水相体系中外加盐（阴、阳离子）、乙醇、蔗糖及柠檬酸对溶液粘度的影响作了探讨性研究,结果表明四种胶溶液（０．１０％黄原胶、０．３０％海藻酸钠、０．２５％瓜尔胶、０．１０％琼脂）中、瓜尔胶溶液对盐的耐受性最好,即大多数阴阳离子都不会对其粘度产生影响,而常用金属盐阳离子及Ｃｌ＾－、ＳＯ３＾２－对黄原胶溶液粘度的影响与阴阳离子对海藻酸钠和琼脂     

红枣银耳复合果冻的研制

为了研制品质优良、营养丰富的果冻,以红枣和银耳为原料进行复合果冻的研制,研究不同凝胶剂的凝胶性能和复配胶的最佳比例,并对复合果冻的配方和制作工艺进行优化。实验结果:复配胶的最佳配比为魔芋胶∶黄原胶∶卡拉胶∶琼脂=2∶1∶1∶1,果冻的最佳配方为:复合果汁(红枣汁∶银耳汁=2∶1)20%,复配胶1.5%,白砂糖12%,柠檬酸0.1%。最优水平组合A2B3C2D1的感官评分为90分。     

Rheological properties of aqueous blends of high purity barley β-glucan with high purity commercial food gums

Rheological properties such as flow behaviour, viscosity, viscoelasticity, and thixotropy of solutions of β-glucan purified from barley fibre concentrate and twelve commonly used food gums, alone and in combinations, were characterised using an oscillatory rheometer. Pure gums and gum combinations were evaluated at 0.5% and 0.75% (w/w) total gum concentration in aqueous medium, whereas the β-glucan/gum ratios were kept at 90/10 or 80/20 (w/w). Viscosity synergism was observed for β-glucan solutions in combination with xanthan, iota-carageenan, and carboxymethyl cellulose. However, barley β-glucan blends with lambda-carageenan, Konjac, high- and low-methoxyl pectin, microcrystalline cellulose, alginate, and gum arabic showed marked lowering of the viscosity compared to β-glucan alone. In addition, β-glucan/xanthan gum blends demonstrated improved shear tolerance compared to xanthan dispersions alone, and soft gel transformation. Non-thixotropic behaviour was observed for 0.5 and 0.75% (w/w) β-glucan dispersions and its gum combinations. None of the gum combinations studied demonstrated thixotropy.     

Relationship between the emulsifying properties of Acacia gums and the retention and diffusion of aroma compounds

Five samples of Acacia senegal gum were selected because of their different emulsifying properties. Acacia gum samples were first characterized by various analytical methods including intrinsic viscosity and arabino-galactan protein amount as determined by gel permeation chromatography. In a second step, stability of emulsions containing orange essential oil and Acacia gums was evaluated by measurement of turbidity. In addition, flavour release of two different hydrophobic aroma compounds from Acacia gum aqueous solutions was studied. Retention was measured using the phase ratio variation method under equilibrium whereas diffusion was assessed by DOSY NMR. This study established the relationship between the emulsifying ability of Acacia gum and the behaviour of aroma compounds in the corresponding solution. Better emulsifying ability of Acacia gum sample appears strongly correlated to an increase in flavour retention and a decrease in molecular mobility as the result of mostly hydrophobic interactions.     

金针菇营养保健果冻的生产工艺

研究金针菇营养保健果冻的加工过程中,复合凝胶剂魔芋粉-琼脂-明胶的配比、凝胶剂的用量、柠檬酸与蔗糖的添加量、煮胶温度和时间对果冻产品品质的影响.结果表明:魔芋粉、琼脂、明胶的配比为2:3:2,总用胶量为0.7%,混合溶解后的胶溶液在75℃煮10min,添加15%的白砂糖,调至pH=5,加入金针菇提取液,凝固后获得透明,口感爽滑,酸甜可口的果冻,具有清香纯正的金针菇风味.     

RHEOLOGICAL PROPERTIES OF AQUEOUS SOLUTIONS OF THE GUMMY EXUDATE OF ZANTHOXYLUM TESSMANNII

Some factors that affect the rheological properties of the aqueous solutions of zanthoxylum gum were studied. The solutions exhibited Newtonian flow at low concentrations, becoming pseudoplastic as concentration increased. It was impossible to obtain a completely wetted mass at concentrations above 25% w/v. The viscosity of the gum solutions reduced irreversibly on storage and when stored at elevated temperature. However, an increase was observed with decrease in storage temperature with the solution turning into a stable gel at 4°C. The gum solutions exhibited characteristics of an acidic polyelectrolyte at dilute concentrations and in the presence of acid and salts. The expected increase in viscosity with added base was not obtained. A thick gel layer formed at interfaces between the gum solution and air, and containers and closures made with polymeric materials. This was attributed to the adsorption and interaction of the gum molecules at these interfaces.