Effect of xanthan gum on the degradation of cereal β-glucan by ascorbic acid

Oat and barley β-glucans are polysaccharides known for their beneficial effects on glycemia and cholesterol. These physiological effects seem to be related to increased viscosity in the digestive tract. It has recently been shown that free radicals derived from the reaction of ascorbic acid and oxygen can cause a viscosity loss in β-glucan due to depolymerization through the Fenton reaction. However, recent studies have reported a synergistic effect between xanthan gum and β-glucan on viscosity in heat-treated fruit juices. Therefore, the objective of this study was to determine if xanthan gum has a protective effect against OH radical-induced depolymerization of β-glucan by ascorbic acid. Oat β-glucan (0.4%) solutions were studied in water at pH 4. Ascorbic acid concentrations and viscosity profiles were measured over a period of 56 days. The addition of ascorbic acid caused a rapid decrease in β-glucan viscosity. The presence of xanthan gum reduced the viscosity loss (p ≤ 0.0001) but did not provide complete protection for β-glucan over time. Therefore, incorporation of β-glucan in food formulations still presents a challenge in ensuring its physical and nutritional stability in the final product. The use of OH radical scavengers such as sugars and antioxidant compounds could be used in addition to xanthan gum to obtain improved protection.     

地毯草黄单胞菌分泌黄原胶的电镜观察

为了研究地毯草黄单胞菌(Xanthomonas axonopodis)FJAT-10151产黄原胶的分泌行为,采用比浊法测定地毯草黄单胞菌的生长曲线,干重法测定黄原胶产量,2,4-二硝基苯肼显色法测定黄原胶中丙酮酸含量变化,通过扫描电子显微镜镜(SEM)和透射电子显微镜镜(TEM)观察地毯草黄单胞菌产黄原胶的分泌行为。FJAT-10151在发酵时间0～26 h为对数期,26～72 h为稳定期。菌株FJAT-10151为短杆状(约2μm),端生鞭毛(约7.9μm),菌体外面形成了一层较厚的荚膜,且许多菌体通过黄原胶连在一起,分泌的黄原胶呈棒状和网状2种形态,聚集或缠绕在细胞表面,其含量随发酵时间的延长而增加。菌株FJAT-10151发酵72 h可获得高品质黄原胶,其产量及丙酮酸含量最高。     

Dough rheological properties and texture of gluten-free pasta based on proso millet flour

Proso millet (PM) is a gluten-free cereal grain with potential to be used in gluten-free product development. However, research on improving the rheological properties of PM dough is limited. In the present study, rheological and color characteristics of PM dough (37% moisture) were compared with the behavior of wheat dough. Three hydrocolloids [guar gum (GG), xanthan gum (XG) and sodium alginate (SA)] at concentrations of 0%, 1% and 2% were added to improve the physical properties of PM dough. The textural properties of PM dough developed pasta with hydrocolloids were also studied. Wheat dough presented a much higher apparent viscosity and elastic modulus than PM dough. Both the apparent viscosity and elasticity were increased by all three hydrocolloids, with 2% XG presenting the most pronounced improvement in elasticity. Generally, the capacity of hydrocolloids to improve the PM dough follow the order XG > GG > SA. The addition of hydrocolloids showed no significant impact on the color of PM dough. GG and XG showed an improvement in the network strength of PM pasta, while SA did not contribute to textural enhancement.     

Flow behavior characteristics of ice cream mix made with buffalo milk and various stabilizers

Ice cream made with buffalo milk, using optimum levels ofvarious stabilizers of plant origin, was evaluated for its flow behaviorcharacteristics, with the objective of producing an acceptable qualityproduct. The minimum variation in the viscosity of mix was observed atthree rates of shear (348.88, 523.33 and 1046.66 S^-1) for all icecream mixes. The flow behavior index (n) of all the mixes having optimumlevels of various stabilizers was observed to be less than 1; indicating theirpseudoplastic nature. Consistency coefficient (m) of sodium alginate wasfound to be 1.19; highest among all the stabilizers, followed by gelatin(1.17), karaya (1.08), guar gum (0.75), acacia gum (0.70), ghatti gum(0.36), and the control (0.29). The consistency coefficient (m) signifiesthe apparent viscosity of the pseudoplastic fluid. The viscosity of the mixeshaving various stabilizers (optimum levels) was found to be in descendingorder: Sodium alginate, gelatin, karaya, guar gum, acacia, ghatti andcontrol.     

An Overview of Potential Seaweed-Derived Bioactive Compounds for Pharmaceutical Applications

Nowadays, seaweeds are widely involved in biotechnological applications. Due to the variety of bioactive compounds in their composition, species of phylum Ochrophyta, class Phaeophyceae, phylum Rhodophyta and Chlorophyta are valuable for the food, cosmetic, pharmaceutical and nutraceutical industries. Seaweeds have been consumed as whole food since ancient times and used to treat several diseases, even though the mechanisms of action were unknown. During the last decades, research has demonstrated that those unique compounds express beneficial properties for human health. Each compound has peculiar properties (e.g., antioxidant, antimicrobial, antiviral activities, etc.) that can be exploited to enhance human health. Seaweed’s extracted polysaccharides are already involved in the pharmaceutical industry, with the aim of replacing synthetic compounds with components of natural origin. This review aims at a better understanding of the recent uses of algae in drug development, with the scope of replacing synthetic compounds and the multiple biotechnological applications that make up seaweed’s potential in industrial companies. Further research is needed to better understand the mechanisms of action of seaweed’s compounds and to embrace the use of seaweeds in pharmaceutical companies and other applications, with the final scope being to produce sustainable and healthier products.     

Agarose Stearate-Carbomer940 as Stabilizer and Rheology Modifier for Surfactant-Free Cosmetic Formulations

Some commonly used surfactants in cosmetic products raise concerns due to their skin-irritating effects and environmental contamination. Multifunctional, high-performance polymers are good alternatives to overcome these problems. In this study, agarose stearate (AS) with emulsifying, thickening, and gel properties was synthesized. Surfactant-free cosmetic formulations were successfully prepared from AS and carbomer₉₄₀ (CBM₉₄₀) mixed systems. The correlation of rheological parameter with skin feeling was determined to study the usability of the mixed systems in cosmetics. Based on rheological analysis, the surfactant-free cosmetic cream (SFC) stabilized by AS-carbomer₉₄₀ showed shear-thinning behavior and strongly synergistic action. The SFC exhibited a gel-like behavior and had rheological properties similar to commercial cosmetic creams. Scanning electron microscope images proved that the AS-CBM₉₄₀ network played an important role in SFC’s stability. Oil content could reinforce the elastic characteristics of the AS-CBM₉₄₀ matrix. The SFCs showed a good appearance and sensation during and after rubbing into skin. The knowledge gained from this study may be useful for designing surfactant-free cosmetic cream with rheological properties that can be tailored for particular commercial cosmetic applications. They may also be useful for producing medicine products with highly viscous or gel-like textures, such as some ointments and wound dressings.     

食用胶对小麦粉面团流变学特性的影响

为明确食用胶在面制食品中的作用,以3种商业小麦粉(特一粉、富强粉、上白粉)为试验材料,分别添加不同比例的海藻酸钠、黄原胶、卡拉胶,分析其对面团流变学特性的影响。结果表明,小麦粉添加0.15%~0.25%的海藻酸钠,面团稳定时间显著提高,弱化度显著降低;添加0.10%、0.20%和0.25%的海藻酸钠,面团最大拉伸阻力显著提高。添加0.02%、0.06%和0.10%的黄原胶,面团最大拉伸阻力显著提高;添加0.10%黄原胶的面团拉伸面积也显著提高。添加0.10%的卡拉胶,面团稳定时间、拉伸面积显著提高,弱化度显著降低。食用胶因小麦粉品质不同对面团流变学特性的影响也不同,除添加0.25%的海藻酸钠外,其他添加量的3种食用胶均可降低特一粉的面团吸水率,提高上白粉的吸水率。研究认为,海藻酸钠、黄原胶、卡拉胶可显著改善小麦粉的面团流变学特性,增强面团筋力。     

Microalgae Encapsulation Systems for Food,Pharmaceutical and Cosmetics Applications

Microalgae are microorganisms with a singular biochemical composition, including several biologically active compounds with proven pharmacological activities, such as anticancer, antioxidant and anti-inflammatory activities, among others. These properties make microalgae an interesting natural resource to be used as a functional ingredient, as well as in the prevention and treatment of diseases, or cosmetic formulations. Nevertheless, natural bioactives often possess inherent chemical instability and/or poor solubility, which are usually associated with low bioavailability. As such, their industrial potential as a health-promoting substance might be severely compromised. In this context, encapsulation systems are considered as a promising and emerging strategy to overcome these shortcomings due to the presence of a surrounding protective layer. Diverse systems have already been reported in the literature for natural bioactives, where some of them have been successfully applied to microalgae compounds. Therefore, this review focuses on exploring encapsulation systems for microalgae biomass, their extracts, or purified bioactives for food, pharmaceutical, and cosmetic purposes. Moreover, this work also covers the most common encapsulation techniques and types of coating materials used, along with the main findings regarding the beneficial effects of these systems.     

Isolation of a novel mutated strain of Xanthomonas campestris for xanthan production using whey as the sole substrate

This study was conducted to isolate novel lactose utilizing Xanthomonas campestris mutants. Such a mutant will assist the utilization of whey as the sole carbon source for xanthan gum production, lower costs of fermentation process and set a precise application for whey as a waste. In this study, a mutant strain (NA1) was isolated from Xanthomonas campestris cells exposed to nitrous acid mutagenesis Environmental conditions were optimized and maximum activity of the beta-galactosidase enzyme was obtained at pH 5.5 and 38 degrees C following which the beta-galactosidase activity in NA1 culture was increased 9.5 folds, compared to that of the wild type culture (336.1 U vs. 35.4 U). Xanthan gum production by NA1 using whey as carbon source was also studied. Using the experimental design of Plackett-Burman and statistical analysis, whey, as the main substrate and pH were the first factors affecting gum production among the seven parameters tested. Gum production using significant factors (such as substrate concentration and pH) was carried out in a lab-scale fermentor and 10 g L(-l) xanthan was obtained.     

Astaxanthin Delivery Systems for Skin Application: A Review

Astaxanthin (AST) is a biomolecule known for its powerful antioxidant effect, which is considered of great importance in biochemical research and has great potential for application in cosmetics, as well as food products that are beneficial to human health and medicines. Unfortunately, its poor solubility in water, chemical instability, and low oral bioavailability make its applications in the cosmetic and pharmaceutical field a major challenge for the development of new products. To favor the search for alternatives to enhance and make possible the use of AST in formulations, this article aimed to review the scientific data on its application in delivery systems. The search was made in databases without time restriction, using keywords such as astaxanthin, delivery systems, skin, cosmetic, topical, and dermal. All delivery systems found, such as liposomes, particulate systems, inclusion complexes, emulsions, and films, presented peculiar advantages able to enhance AST properties, among which are stability, antioxidant potential, biological activities, and drug release. This survey showed that further studies are needed for the industrial development of new AST-containing cosmetics and topical formulations.     

A spray technique for mass release of eggs of Micromus tasmaniae Walker (neuroptera: Hemerobiidae)

Laboratory and glasshouse tests showed that eggs of Micromus tasmaniae Walker (Neuroptera: Hemerobiidae) can be sprayed at 206 kPa pressure with a specially developed compressed-air sprayer without impairing viability. The effects of five materials (agar, sucrose, gelatin, plant glue and xanthan gum) in water solution on egg hatching were tested and xanthan gum solution (0·03%) was selected as a suitable liquid medium for suspending the eggs and making them adhere to potato foliage. Egg losses during spraying may be greatly affected by wind drift, the amount of exposed soil (which is related to the stage of foliage development) and other environmental factors. The possibility of a spray technique for mass release of M. tasmaniae eggs in the biological control programme for potato pests is discussed.     

Carrageenan: Drug Delivery Systems and Other Biomedical Applications

Marine resources are today a renewable source of various compounds, such as polysaccharides, that are used in the pharmaceutical, medical, cosmetic, and food fields. In recent years, considerable attention has been focused on carrageenan-based biomaterials due to their multifunctional qualities, including biodegradability, biocompatibility, and non-toxicity, in addition to bioactive attributes, such as their antiviral, antibacterial, antihyperlipidemic, anticoagulant, antioxidant, antitumor, and immunomodulating properties. They have been applied in pharmaceutical formulations as both their bioactive and physicochemical properties make them suitable biomaterials for drug delivery, and recently for the development of tissue engineering. This article provides a review of recent research on the various types of carrageenan-based biomedical and pharmaceutical applications.     

Rheological characterization of jet-cooked Lesquerella fendleri seed gum and cornstarch solutions

Lesquerella is a potential new seed crop that contains hydroxy fatty acid triglycerides and approximately 15% seed coat gums. The polysaccharide gum of the Lesquerella fendleri seed was isolated and jet-cooked with cornstarch in a series of laboratory experiments to investigate the viscoelastic properties of gum-modified starch solutions. The Lesquerella gum was combined with cornstarch at 1, 5, and 10% levels to produce a jet-cooked and drum dried material with potential application as a thickening or suspension agent. Flow curves were determined for 1% solutions of jet-cooked starch and gum combinations. All materials investigated were biodegradable and exhibited positive thixotropic behavior.     

Constitutive equations for dilute bubble suspensions and rheological behavior in simple shear and uniaxial elongational flow fields

A theoretical model is proposed in order to investigate rheological behavior of bubble suspension with large deformation. Theoretical constitutive equations for dilute bubble suspensions are derived by applying a deformation theory of ellipsoidal droplet [1] to a phenomenological suspension theory [2]. The rate of deformation tensor within the bubble and the time evolution of interface tensor are predicted by applying the proposed constitutive equations, which have two free fitting parameters. The transient and steady rheological properties of dilute bubble suspensions are studied for several capillary numbers (Ca) under simple shear flow and uniaxial elongational flow fields. The retraction force of the bubble caused by the interfacial tension increases as bubbles undergo deformation. The transient and steady relative viscosity decreases asCa increases. The normal stress difference (NSD) under the simple shear has the largest value whenCa is around 1 and the ratio of the first NSD to the second NSD has the value of 3/4 for largeCa but 2 for smallCa. In the uniaxial elongational flow, the elongational viscosity is three times as large as the shear viscosity like the Newtonian fluid.     

The Seaweed Diet in Prevention and Treatment of the Neurodegenerative Diseases

Edible marine algae are rich in bioactive compounds and are, therefore, a source of bioavailable proteins, long chain polysaccharides that behave as low-calorie soluble fibers, metabolically necessary minerals, vitamins, polyunsaturated fatty acids, and antioxidants. Marine algae were used primarily as gelling agents and thickeners (phycocolloids) in food and pharmaceutical industries in the last century, but recent research has revealed their potential as a source of useful compounds for the pharmaceutical, medical, and cosmetic industries. The green, red, and brown algae have been shown to have useful therapeutic properties in the prevention and treatment of neurodegenerative diseases: Parkinson, Alzheimer’s, and Multiple Sclerosis, and other chronic diseases. In this review are listed and described the main components of a suitable diet for patients with these diseases. In addition, compounds derived from macroalgae and their neurophysiological activities are described.     

Antioxidant activity of Hawaiian marine algae

Marine algae are known to contain a wide variety of bioactive compounds, many of which have commercial applications in pharmaceutical, medical, cosmetic, nutraceutical, food and agricultural industries. Natural antioxidants, found in many algae, are important bioactive compounds that play an important role against various diseases and ageing processes through protection of cells from oxidative damage. In this respect, relatively little is known about the bioactivity of Hawaiian algae that could be a potential natural source of such antioxidants. The total antioxidant activity of organic extracts of 37 algal samples, comprising of 30 species of Hawaiian algae from 27 different genera was determined. The activity was determined by employing the FRAP (Ferric Reducing Antioxidant Power) assays. Of the algae tested, the extract of Turbinaria ornata was found to be the most active. Bioassay-guided fractionation of this extract led to the isolation of a variety of different carotenoids as the active principles. The major bioactive antioxidant compound was identified as the carotenoid fucoxanthin. These results show, for the first time, that numerous Hawaiian algae exhibit significant antioxidant activity, a property that could lead to their application in one of many useful healthcare or related products as well as in chemoprevention of a variety of diseases including cancer.     

Thermal and rheological properties of brown flour from Indica rice

The thermal, paste and rheological properties of brown flours from four Indica rice subspecies with different amylose content were examined using Differential scanning calorimetry (DSC), Brabender Viscometer and rheometer. Peak, final and setback viscosities (p < 0.05) increased with increasing amylose content from Brabender micro Visco-Amylo-Graph (MVA), but the phase transition temperatures of brown rice flour from DSC (p < 0.05) decreased with increasing amylose content. Rheological properties were determined by steady shear, small amplitude oscillatory shear (SAOS) and thixotropic experiments. SAOS results showed a gel-like viscoelastic behavior with G′ higher than G″. Steady-shear results showed that the brown rice flour exhibited a non-Newtonian shear-thinning behavior and the flow curves can be well described by the Herschel-Bulkley model. The upward-downward rheograms showed that brown rice flour gel, except IR-1, had a hysteresis loop, indicating a strong thixotropic behavior.     

Impact of guar and xanthan gums on proofing and calorimetric parameters of frozen bread dough

The influence of guar and xanthan gum and their combined use on dough proofing rate and its calorimetric properties was investigated. Fusion enthalpy, which is related to the amount of frozen water, was influenced by frozen dough formulation and storage time; specifically gum addition reduced the fusion enthalpy in comparison to control formulation, 76.9 J/g for formulation with both gums and 81.2 J/g for control, at 28th day. Other calorimetric parameters, such as T_g and freezable water amount, were also influenced by frozen storage time. For all formulations, proofing rate of dough after freezing, frozen storage time and thawing, decreased in comparison to non-frozen dough, indicating that the freezing process itself was more detrimental to the proofing rate than storage time. For all formulations, the mean value of proofing rate was 2.97 ± 0.24 cm³ min⁻¹ per 100 g of non-frozen dough and 2.22 ± 0.12 cm³ min⁻¹ per 100 g of frozen dough. Also the proofing rate of non-frozen dough with xanthan gum decreased significantly in relation to dough without gums and dough with only guar gum. Optical microscopy analyses showed that the gas cell production after frozen storage period was reduced, which is in agreement with the proofing rate results.     

Effect of pH and ethanol content of solvent on rheology of zein solutions

Zein, a corn protein, is a mixture of the polypeptides α-, γ-, β-, and δ-zein. α-Zein and γ-zein comprise 70–85% and 10–20% of total zein mass, respectively. Both peptides have similar amino acid composition, except γ-zein is rich in cysteine. The presence of cysteine has been associated with gelation of zein solutions. A common solvent for zein is aqueous ethanol. Preliminary results suggested that pH and ethanol content affect the rheology of zein solutions. Our objective was to investigate the effect of ethanol content (65–90%) and pH of the solvent (2, 6, and 12) on rheological properties of zein solutions (20% w/w) containing γ-zein. Steady shear tests and oscillatory time sweeps were performed to determine flow behavior and gelation time of zein solutions. Results indicated that α-zein solutions were nearly Newtonian while those containing γ-zein showed shear thinning behavior. At high pH, γ-zein increased the consistency index (K) and shortened gelation time. Results were attributed to the cysteine in γ-zein. High pH promoted formation of disulfide bonds leading to higher K values and shorter gelation times. Results of this work are expected to be useful in the design of zein extraction processes and the development of new zein applications.     

Emulsifying properties of three African food hydrocolloids: okra (Hibiscus esculentus), dika nut (Irvingia gabonensis), and khan (Belschmiedia sp.)

This study investigated the emulsifying properties of okra (Hibiscus esculentus), dika nut (Irvingia gabonensis) and khan (Belschmiedia sp.), three African food hydrocolloids used to thicken and flavor soups. Results showed that khan has an emulsion potential approximately 20 and 100 times higher than the second and the first, respectively. A kinetic study indicated that the mechanism involved formation of thick and strong interfacial gum films around the oil globules, in addition to a high Water Absorption Capacity and weak gelling behavior of khan gum in solution. These results indicated that, when used in soups, which are typical oil/water emulsions, khan contribute both to thickening and stabilizing of the emulsion, whereas okra and dika nut functioned more as thickeners than as emulsion stabilizers.