The effect of various hydrocolloids on some physical properties of extruded corn grits

Fourteen hydrocolloids including Methocels (A4M, E4M, F4M and K4M), locust bean, guar, agar, arabic, alginate, tragacanth, carrageenan, xanthan, pectin, and gelatin gums were extruded at levels of 0, 0.1, 0.5 and 1.0% with corn grits in a Brabender Model PL-V500 extruder at barrel temperatures of 50, 75, 100, 125 and 150°C with a 1:1 screw operating at 100 rpm. Resulting products were evaluated for density, breaking strength and water absorption. Significant differences were found as influenced by hydrocolloid type/amount and extrusion temperature. In general, hydrocolloid additions significantly increased product density and either increased or decreased breaking strength and water absorption.     

The effect of viscous substances on the transit time of barley digesta in rats

The influence of a number of hydrocolloids on the transit time of digesta, stool weight and colour of stools was investigated in rats. All hydrocolloids tested gave the stools a lighter colour and increased their size and water content. The hydrocolloids could be divided into two groups according to their action on digesta passage: pectin, gum arabic, oxidised starch and barley β-glucan retarded it, while guar gum, carrageenan, tragacanth gum, carob bean gum, sodium alginate and sodium carboxymethyl cellulose accelerated it. After feeding carrageenan for 1 week it took several weeks before water content and transit time returned to normal. Gum arabic was found to cause caecal distension.     

Determination of Pectin in the Presence of Food Polysaccharides

A selective and specific method to assay pectin in mixtures of polysaccharides using pectinase was developed. The mixture was extracted with 99.5% (v/v) ethanol to remove gum arabic and any other ethanol-soluble saccharides and polysaccharides; pectin was then hydrolyzed with pectinase. The hydrolyzed pectin was recovered by solution in 80% (v/v) ethanol and assayed by the m-hydroxybiphenyl method. The assay was not affected by agar and gums of tragacanth, karaya, guar, and locust bean in the mixture. Alginate and xanthan gum in the mixture repressed the development of color by this method, but this effect could be offset by modification of the pectinase reaction system.     

Moving Boundary Electrophoresis of Food Stabilizers

SUMMARY— The electrophoretic characteristics of locust bean gum, guar gum, arabic gum, carboxymethylcellulose, K- and h-carrageenan, alginate and the non-dialyzable fraction of corn syrup solids were studied by moving boundary electrophoresis. The physical properties of these colloids require the use of modified techniques in order to eliminate boundary disturbances which otherwise might be interpreted as heterogeneity of composition.
A high degree of homogeneity was observed for carboxymethylcellulose, arabic gum, alginate and X-carrageenan. In contrast, K-carrageenan was composed of a mixture of migrating components. The colloidal fractions of guar gum, locust bean gum, and corn syrup solids did not migrate in the electrical field.
Mixtures of carboxymethylcellulose with guar gum or gum arabic could be separated at pH 7. Mixtures of carboxymethylcellulose with carrageenan could be effectively separated at pH 2. Electrophoretic separation at 23°C of different stabilizer mixtures was unsatisfactory and the patterns showed evidence of interactions.     

Effect of Various Encapsulating Materials on the Stability of Probiotic Bacteria

ABSTRACT:  Ten probiotic bacteria, including Lactobacillus rhamnosus , Bifidobacterium longum , L. salivarius , L. plantarum , L. acidophilus , L. paracasei , B. lactis type Bl-04, B. lactis type Bi-07, HOWARU L. rhamnosus , and HOWARU B. bifidum , were encapsulated in various coating materials, namely alginate, guar gum, xanthan gum, locust bean gum, and carrageenan gum. The various encapsulated probiotic bacteria were studied for their acid and bile tolerance. Free probiotic organisms were used as a control. The acid tolerance of probiotic organisms was tested at pH 2 over a 2-h incubation period. Bile tolerance was tested with taurocholic acid over an 8-h incubation period. The permeability of the capsules was also examined using a water-soluble dye, 6-carboxyflourescin (6-CF). The permeability was monitored by measuring the amount of 6-CF released from the capsules during a 2-w storage period. Results indicated that probiotic bacteria encapsulated in alginate, xanthan gum, and carrageenan gum survived better ( P < 0.05) than free probiotic bacteria, under acidic conditions. When free probiotic bacteria were exposed to taurocholic acid, viability was reduced by 6.36 log CFU/mL, whereas only 3.63, 3.27, and 4.12 log CFU/mL was lost in probiotic organisms encapsulated in alginate, xanthan gum, and carrageenan gum, respectively. All encapsulating materials tested released small amounts of 6-CF; however, alginate and xanthan gum retained 22.1% and 18.6% more fluorescent dye than guar gum. In general, microcapsules made of alginate, xanthan gum, and carrageenan gum greatly improved the survival of probiotic bacteria when exposed to acidic conditions and bile salts.     

基于亲水胶体改性和混料设计优化传统粘豆包的配方

目的 用亲水胶体改性和混料设计来优化传统粘豆包的配方, 改善其食用品质。方法 选用3种食品工业中常用的亲水胶体, 卡拉胶、黄原胶和瓜尔豆胶, 对糯玉米与糯大黄米淀粉进行改性, 通过快速粘度分析仪和质构仪比较回生值和硬度的变化, 筛选出复配糯玉米粉和复配大黄米粉作为粘豆包的制作原料, 然后利用混料设计优化粘豆包配方。结果 卡拉胶、黄原胶、瓜尔豆胶对糯性谷物淀粉有着良好的抗老化作用, 回生值都明显变小, 尤其瓜尔豆胶效果最明显; 通过混料设计发现当糯大黄米为33%, 糯玉米粉为24%, 红豆馅为43%时感官评分最高。结论 利用混料设计优化传统粘豆包的生产配方, 感官评分高, 传统粘豆包品质得到改善。     

天然亲水性胶体对山药混汁悬浮稳定性的影响

研究天然亲水性胶体对山药混汁悬浮稳定性的影响。在山药混汁中分别添加不同种类的单一胶体和复配胶作为稳定剂,以样品离心前后的浊度差为评价指标,结合单因素试验和正交试验的方法对山药混汁悬浮稳定性进行研究。结果表明：褐藻酸钠、瓜尔豆胶和果胶三种单体稳定剂分别对山药混汁悬浮稳定性的影响显著,呈现一定的规律性,同时3种胶体复配使用对山药混汁的稳定性有更好的作用。其复配稳定剂用量配方为褐藻酸钠0.17%、瓜尔豆胶0.10%、果胶0.17%。     

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     

Determination of the fruit content of cherry fruit preparations by gravimetric quantification of hemicellulose

A method recently developed for the determination of the fruit content of strawberry fruit preparations by gravimetric quantification of hemicellulose was extended to cherry fruit preparations. Isolation of the alcohol-insoluble residue (AIR) and sequential fractionation of the cell wall compounds from cherries (Prunus cerasus L. cv. ‘Oblacinska’) was performed yielding the amount of fresh cherries per gram hemicellulose. Cherry fruit preparations with varying fruit contents (30–40%) were produced using different hydrocolloid systems (pectin, starch, guar gum, xanthan gum, carrageenan, and combinations thereof). After separation of the hydrocolloids by enzymatical digestion and successive extraction, the fruit preparations were subjected to AIR isolation. The AIR was fractionated to yield the hemicellulose fraction, which was quantified gravimetrically for the calculation of the fruit content. Compared to strawberries, modifications including additional extraction steps for the sequential fractionation were required to separate the pectin of the cherries exhaustively. Calculated and initial fruit contents were in good agreement for the single hydrocolloid components pectin and starch as well as for the combinations pectin/xanthan gum and pectin/carrageenan (26.8% vs. 30%, 38.6% vs. 40%, 42.5% vs. 40%, 37.6% vs. 40%, and 41.2% vs. 40%), whereas the preparations produced with more complex hydrocolloid systems (pectin/xanthan gum/guar gum and starch/xanthan/guar gum) showed larger deviations in their contents (46.2% vs. 40%, 49.6% vs. 40%). It is concluded that the novel method is generally suitable for the determination of the fruit content of fruit preparations, but steps of sample preparation need to be individually adapted to the different fruit matrices.     

Enrichment of Genistein in Soy Protein Concentrate with Hydrocolloids and β-glucosidase

ABSTRACT: The effects of hydrocolloid (propylene glycol alginate, K-carrageenan, citrus pectin, and xanthan gum) additions in soy protein concentrate (SPC) preparation on genistin and genistein retentions were investigated. Additions of xanthan, alginate, pectin, and carrageenan in SPC prepared with the acid leach method gave 0.711, 0.760, 0.792, and 0.825 mg/g genistein, respectively, whereas control SPC prepared without hydrocolloid gave 0.721 mg/g genistein. SPC prepared under optimum conditions for (β-glucosidase hydrolytic activity with xanthan, alginate, carrageenan, and pectin had 0.943, 0.975, 1.015, and 1.132 mg/g genistein, respectively, compared to genistein in control SPC (0.845 mg/g) under the optimum conditions. Combined (β-glucosidase and pectin treatment in SPC preparation resulted in high genistein SPC (1.551 mg/g).     

Rheological characterisation of selected food hydrocolloids by traditional and simplified techniques

Empirical and fundamental rheological properties of six food hydrocolloids (carboxymethylcellulose, tara gum, guar gum, locust bean gum, xanthan gum and sodium alginate), as influenced by concentration, were evaluated and correlated. Furthermore, the possibility to estimate the empirical and fundamental parameters by using data coming from a very simple and inexpensive rotational viscometer prototype, was investigated. The prototype was build in laboratory and its simplicity consist of the capability to directly measure a voltage, correlated with the absorbed current, instead of a derived torque and rotation speed measurements of the cylinder probe. Fundamental rheological measurements were performed by using a controlled stress-strain rheometer, while a back extrusion test was performed in order to evaluate the empirical properties.     

雪莲果芹菜复合饮料工艺研究

根据感官评分确定雪莲果芹菜复合饮料的配方,研究黄原胶、卡拉胶、瓜尔豆胶、明胶、羧甲基纤维素钠、海藻酸钠等6种稳定剂对雪莲果芹菜复合饮料稳定性的影响,并通过正交试验确定复合饮料的最适稳定剂及其质量分数。结果表明,复合饮料配方为:雪莲果汁40%,芹菜汁20%,蛋白糖0.12%;对复合饮料稳定性较好的稳定剂及其质量分数范围为:黄原胶0.03%~0.09%、卡拉胶0.05%~0.15%、海藻酸钠0.05%~0.15%;复合稳定剂及其质量分数为:黄原胶0.07%,卡拉胶0.06%,海藻酸钠0.08%。     

Factors Affecting Adhesion of Coating to Poultry Skin: Effects of Various Protein and Gum Sources in the Coating Composition

Breading losses from poor adhesion of coating to food products is a major concern in the battered and breaded foods industry. The primary aim of this study was to determine effects of protein and gum sources and amounts on the adhesion of a commercial breading mix to poultry skin. Protein sources used were whey, soy, nonfat dry milk, egg albumen, and gelatin. Gum sources were sodium carboxymethyl cellulose (CMC), guar, tragacanth, and xanthan. Among the proteins, gelatin and egg albumen most effectively improved adhesion. For all gums studied, only CMC was significantly better at improving adhesion. Increased levels of gums and proteins in breading did not affect adhesion significantly.     

Hydrocolloids in emulsions: particle size distribution and interfacial activity

The emulsification properties of 14 hydrocolloid gums (propylene glycol alginate, gellan, carrageenan, pectin, methylcellulose, microcrystalline cellulose, gum arabic, locust bean gum, guar, xanthan, mustard, flaxseed, fenugreek, oat) were investigated. Gum dispersions were prepared in water (0.5%) and emulsified with 40% oil using a Polytron homogenizer. Emulsion stability was determined by centrifugation and storage time, surface and interfacial tension by Du Nouy ring, particle size by integrated light scattering and overall morphology by light microscopy. When compared to the other gums in this study, fenugreek produced a very stable emulsion. Fenugreek was more efficient than other gums in lowering the interfacial free energy, its emulsion was composed of very small oil droplets (70%<1 μm) and under the light microscope appeared as uniform droplets with a narrow size distribution.     

南瓜菠萝胡萝卜复合饮料加工工艺研究

以感官评分为指标,采用正交试验确定了南瓜、菠萝、胡萝卜复合饮料的配方;研究了黄原胶、卡拉胶、瓜尔豆胶、明胶、羧甲基纤维素钠(CMC)、海藻酸钠等6种稳定剂对南瓜、菠萝、胡萝卜复合饮料稳定性的影响,并通过正交试验确定了复合饮料的最适稳定剂及其质量分数。结果表明,复合饮料配方为:南瓜汁20%,菠萝汁15%,胡萝卜汁25%,木糖醇1.0%,蛋白糖0.10%;对复合饮料稳定性较好的复合稳定剂及其质量分数为:黄原胶0.10%,CMC 0.08%,卡拉胶0.01%。     

Rheological properties of selected hydrocolloids as a function of concentration and temperature

In this study, rheological properties of several food hydrocolloids (carrageenan, pectin, gelatin, starch and xanthan) were evaluated using a rotational viscometer at three concentrations (1–6%, depending on the type of hydrocolloid) and four temperatures (20, 40, 60 and 80°C). Samples were subjected to a programmed shear rate increasing linearly from 0 to 300 s⁻¹ in 3 min, followed by a steady shear at 300 s⁻¹ for 10 min and finally a linearly decreasing shear rate from 300 s⁻¹ to 0 in 3 min. Experiments were performed in duplicate. In general, the power law model fitted most of the experimental results. Xanthan gum and carrageenan (at 20^oC) were exceptions, characterized by a yield stress and hence the rheograms were fitted with the Herschel-Bulkley model. Furthermore, gelatin showed a Newtonian behavior. Three models (power, exponential and polynomial) were used to evaluate the concentration effect on apparent viscosity. Arrhenius model was used to describe the temperature effect. Among the samples, carrageenan showed the most temperature dependency and xanthan gum, the least.     

增稠剂对酸奶质地的影响研究

对酸奶的硬度、黏度、凝聚性、保水性进行测定，研究了不同增稠剂对酸奶质地和感官特性的影响。结果表明。果胶、明胶、耐酸CMC、海藻酸钠分别提高了酸奶的黏度，而槐豆胶、瓜尔豆胶、魔芋胶则相反；只有果胶和明胶提高了酸奶的保水力；果胶、明胶时酸奶质地的影响随着浓度的增加而增加。统计结果表明，当增稠剂添加量为0．1％时，不同增稠剂对酸奶的质地存在显著影响；同时．增稠荆浓度对酸奶质地的影响也显著。     

亲水胶体对糯玉米汁稳定性影响

为进一步提高糯玉米汁稳定性,比较研究不同亲水胶体(黄原胶、海藻酸钠、瓜尔豆胶和刺槐豆胶)对糯玉米汁体系稳定系数、离心沉淀率、相对黏度和感官的影响,并探讨糯玉米汁体系的静电稳定性。结果表明：黄原胶具有一定的乳化效果,可以在一定程度上缓解糯玉米汁脂肪圈的形成;海藻酸钠、瓜尔豆胶和刺槐豆胶对糯玉米汁的稳定效果较好,并且随着添加量的增加,体系稳定系数和相对黏度逐渐提高;而黄原胶与海藻酸钠、瓜尔豆胶、刺槐豆胶分别以不同质量比复配时,在黄原胶、刺槐豆胶质量比1:4时,糯玉米汁体系稳定性最佳。     

Effect of polysaccharides with different ionic charge on the rheological,microstructural and textural properties of acid milk gels

The effects of addition of polysaccharides with different ionic charge on rheology, microstructure, texture and water holding capacity (WHC) of acid milk gels were studied and compared to that of gelatin addition. Similar to gelatin, starch (neutral) and xanthan gum (anionic) did not prevent milk gelation in the first 30 min of the acidification stage, even at high concentrations, and the typical casein network in acid milk gels could still be seen from electron micrographs; gelling and melting of these hydrocolloids were observed during the cooling and heating stages at specific concentrations. On the other hand, two neutral polysaccharides, guar gum (≥ 0.05%) and locust bean gum [LBG] (≥ 0.1%) inhibited milk gelation from the beginning of the acidification stage; the microstructure of the gel was modified greatly and no gelling/melting was observed during the cooling or heating stages. Another anionic polysaccharide, carrageenan, induced earlier milk gelation at low concentration (≤ 0.05%), but inhibited gelation entirely at high concentration (0.2%); inflections at ~ 27 °C and 21 °C were also observed during the cooling and heating stages at 0.05% concentration. The gel microstructure was not changed greatly, but showed smaller particle size at a carrageenan concentration of 0.05% than control sample. None of the polysaccharides showed as much improvement in WHC of the milk gels as gelatin did. Hence, xanthan and starch were found to be closer to gelatin in their effect on acid milk gels compared to guar gum, LBG and carrageenan.