Edible coatings incorporating pomegranate peel extract and biocontrol yeast to reduce Penicillium digitatum postharvest decay of oranges

This study investigated the potential use of two edible coatings, chitosan (CH) and locust bean gum (LBG), which incorporated chemically characterized water pomegranate peel extract (WPPE) or methanol pomegranate peel extract (MPPE) and the biocontrol agent (BCA) Wickerhamomyces anomalus, to control the growth of Penicillium digitatum and to reduce the postharvest decay of oranges. CH and LBG including pomegranate peel extracts (PPEs) at different concentrations were tested in vitro against P. digitatum to determine their antifungal efficacy; at the same time, the tolerance of viable cells of W. anomalus to increasing concentrations of WPPE and MPPE extracts was assessed. The potential application of selected bioactive coatings was evaluated in vivo on oranges, which had been artificially inoculated with P. digitatum, causal agent of green mold decay. CH incorporating MPPE or WPPE at all concentrations was able to inhibit in vitro P. digitatum, while LBG was active only at the highest MPPE or WPPE concentrations. W. anomalus BS91 was slightly inhibited only by MPPE-modified coatings, while no inhibition was observed by WPPE, which was therefore selected for the in vivo trials on oranges artificially inoculated with P. digitatum. The experimental results proved that the addition of 0.361 g dry WPPE/mL, both to CH and LBG coatings, significantly reduced disease incidence (DI) by 49 and 28% respectively, with respect to the relative controls. Besides the combination CH or LBG + WPPE, the addition of W. anomalus cells to coatings strengthened the antifungal effect with respect to the relative controls, as demonstrated by the significant reduction of DI (up to 95 and 75% respectively). The findings of the study contribute to the valorization of a value-added industrial byproduct and provide a significant advancement in the development of new food protectant formulations, which benefit from the synergistic effect between biocontrol agents and natural bioactive compounds.

Physical properties and antifungal activity of bioactive films containing Wickerhamomyces anomalus killer yeast and their application for preservation of oranges and control of postharvest green mold caused by Penicillium digitatum

This study assessed the ability of two bio-based films, obtained from sodium alginate (NaAlg) and locust bean gum (LBG), to protect the viability of Wickerhamomyces anomalus cells and control the growth of Penicillium digitatum. The effect of microbial cell incorporation on physical properties of the developed films was evaluated in terms of barrier, mechanical and optical properties. Furthermore, the application of these two matrices as bioactive coatings was investigated in order to evaluate their efficacy in preserving the postharvest quality of 'Valencia' oranges and inhibiting the growth of P. digitatum on artificially inoculated fruits. Results showed that NaAlg and LBG films were able to maintain more than 85% of the initial W. anomalus yeast population and that the developed films incorporating the killer yeast completely inhibited the growth of P. digitatum in synthetic medium. Likewise, NaAlg and LBG coatings enriched with W. anomalus yeast were effective at reducing weight loss and maintaining firmness of 'Valencia' oranges during storage, and reduced green mold in inoculated fruits by more than 73% after 13 days.

κ-Carrageenan/locust bean gum as hard capsule gelling agents

A novel gelling agent, comprising blended κ-carrageenan (κ-C), a seaweed polysaccharide and locust bean gum (LBG), was used to prepare hard capsules. The distinct synergism between κ-C and LBG were verified by the textural profile analysis (TPA), FTIR and rheological measurement. Afterwards, films and hard capsules were prepared with the optimized LBG/κ-C blend gel. And the mechanical properties and morphology of films and hard capsules were analyzed by tensile testing and SEM, respectively. The results showed that the LBG/κ-C at 1:3 ratio could serve as an excellent gelling agent, which endowed hard capsule with the promoted mechanical properties, homogenous and smooth surface morphology. This work suggests that a novel blended LBG/κ-C gelling agent successfully prepared for hard capsules with improving physicochemical properties.

Effect of carboxymethylation on rheological and drug release characteristics of locust bean gum matrix tablets

This study was undertaken to investigate correlation between the carboxymethylation-induced rheological changes and drug release characteristics of locust bean gum (LBG) matrix tablets. LBG was derivatized to carboxymethyl LBG (CMLBG) and characterized by (13)C NMR, FTIR and elemental analyses. Rheological studies revealed that LBG, in contact with water, produced a strong elastic gel which swelled less due to lower penetration of water resulting in slower drug release. On the other hand, CMLBG formed a viscous polymer solution through which higher influx of water resulted in rapid swelling of the matrix and faster drug release. Although the release from a particular matrix was dependent on drugs' solubilities, CMLBG matrix tablet produced faster release of all the drugs than LBG matrix tablets. In conclusion, rheological study appeared to be an useful tool to predict release of drugs from polysaccharide matrix tablets.

Study of locust bean gum reinforced cyst-chitosan and oxidized dextran based semi-IPN cryogel dressing for hemostatic application

Severe blood loss due to traumatic injuries remains one of the leading causes of death in emergency settings. Chitosan continues to be the candidate material for hemostatic applications due to its inherent hemostatic properties. However, available chitosan-based dressings have been reported to have an acidic odor at the wound site due to the incorporation of acid based solvents for their fabrication and deformation under compression owing to low mechanical strength limiting its usability. In the present study semi-IPN cryogel was fabricated via Schiff's base cross-linking between the polyaldehyde groups of oxidized dextran and thiolated chitosan in presence of locust bean gum (LBG) known for its hydrophilicity. Polymerization at -12 °C yielded macroporous semi-IPN cryogels with an average pore size of 124.57 ± 20.31 μm and 85.46% porosity. The hydrophobicity index of LBG reinforced semi-IPN cryogel was reduced 2.42 times whereas the swelling ratio was increased by 156.08% compare to control cryogel. The increased hydrophilicity and swelling ratio inflated the compressive modulus from 28.1 kPa to 33.85 for LBG reinforced semi-IPN cryogel. The structural stability and constant degradation medium pH were also recorded over a period of 12 weeks. The cryogels demonstrated lower adsorption affinity towards BSA. The cytotoxicity assays (direct, indirect) with 3T3-L1 fibroblast cells confirmed the cytocompatibility of the cryogels. The hemolysis assay showed <5% hemolysis confirming blood compatibility of the fabricated cryogel, while whole blood clotting and platelet adhesion assays confirmed the hemostatic potential of semi-IPN cryogel.

Locust bean gum in the development of sustained release mucoadhesive macromolecules of aceclofenac

The study shows the development and optimization of locust bean gum (LBG)-alginate mucoadhesive macromolecules containing aceclofenac through ionotropic-gelation using 3(2) factorial design. The effect of amount of LBG and sodium alginate on drug entrapment efficiency (%DEE), % mucoadhesion at 8h (M8) and % in vitro drug release at 10h (%Q10h) were optimized. The percentage yield, average size and DEE of macromolecules were found within the range of 93.19 to 96.65%, 1.328 ± 0.11 to 1.428 ± 0.13 μm, and 56.37 to 68.54%, respectively. The macromolecules were also characterized by SEM, FTIR and DSC. The in vitro drug release from these macromolecules (84.95 ± 2.02 to 95.33 ± 1.56% at 10h) exhibited sustained release (first-order) pattern with super case-II transport mechanism. The swelling and mucoadhesivity of these macromolecules were affected by pH of the medium. The design established the role of derived polynomial equations and plots in predicting the values of dependent variables for the preparation and optimization.

Impact of purification and fractionation process on the chemical structure and physical properties of locust bean gum

Crude locust bean gum (CLBG) was purified and fractionated into two parts: the first was obtained by solubilization in water at 25°C (GM25) and the second consisted in a further extraction at 80°C on the residual impoverished fraction (GM80). The complete structural characterization has shown that GM80 possessed relatively longer chain lengths than GM25, a slightly lower degree of galactose substitution and a somewhat sharper galactosyl distribution in substituted and unsubstituted regions. A physical behavior analysis was carried out on solubilization kinetics, viscosity, viscoelasticity and formation of associated gels with xanthan or carrageenan. The average structure of GM80 generated larger intra-chain, inter-chain and inter-molecular interactions, resulting in the appearance of a stronger network. Small structural differences therefore generated very different physical behaviors. This study thus allowed to establish, in a precise and complete manner, fractionation-purification-structure-function relationships of galactomannans extracted from carob.

A facile synthesis of graphene oxide/locust bean gum hybrid aerogel for water purification

Graphene oxide/locust bean gum (GO/LBG) aerogels, synthesized in an ice crystal template without using any chemical modifiers, were used for the treatment of water pollution. Various characterization results showed that GO/LBG aerogel exhibited a network-like three-dimensional (3D) structure with large specific surface area. The adsorption data revealed that GO/LBG aerogels with GO/LBG mass ratio of 1:4 (GO/LBG-1 aerogels) exhibited more prominent adsorption properties for Rhodamine-B (RhB, 514.5 mgg^-1) than Indigo Carmine (IC, 134.6 mgg^-1). Simultaneously, GO/LBG-1 aerogels could selectively remove RhB from a binary mixed solution of RhB-IC dyes. Furthermore, GO/LBG-1 aerogels also displayed excellent reusability and could still reach 92.4 % after ten cycles. Based on the above results, GO/LBG-1 aerogel could be considered as an ideal adsorbent with potential application value for removing water-soluble RhB from wastewater.

Locust bean gum safety in neonates and young infants: an integrated review of the toxicological database and clinical evidence

Locust bean gum (LBG) is a galactomannan polysaccharide used as thickener in infant formulas with the therapeutic aim to treat uncomplicated gastroesophageal reflux (GER). Since its use in young infants below 12weeks of age is not explicitly covered by the current scientific concept of the derivation of health based guidance values, the present integrated safety review aimed to compile all the relevant preclinical toxicological studies and to combine them with substantial evidence gathered from the clinical paediatric use as part of the weight of evidence supporting the safety in young infants below 12weeks of age. LBG was demonstrated to have very low toxicity in preclinical studies mainly resulting from its indigestible nature leading to negligible systemic bioavailability and only possibly influencing tolerance. A standard therapeutic level of 0.5g/100mL in thickened infant formula is shown to confer a sufficiently protective Margin of Safety. LBG was not associated with any adverse toxic or nutritional effects in healthy term infants, while there are limited case-reports of possible adverse effects in preterms receiving the thickener inappropriately. Altogether, it can be concluded that LBG is safe for its intended therapeutic use in term-born infants to treat uncomplicated regurgitation from birth onwards.

Smart packaging films based on locust bean gum, polyvinyl alcohol, the crude extract of Loropetalum chinense var. rubrum petals and its purified fractions

Loropetalum chinense var. rubrum is an ornamental shrub rich in polyphenolic compounds. In this study, polyphenolic compounds were extracted from L. chinense var. rubrum petals (LCP) and further purified on macroporous resin column to afford two fractions. The crude extract of LCP (LCP-CE) and its two purified fractions (LCP-25PF and LCP-50PF) were individually incorporated into locust bean gum/polyvinyl alcohol matrix to develop smart packaging films. The structures, physical and functional properties of the films were compared. Results showed LCP-25PF was mainly composed of anthocyanins, while LCP-50PF was mainly composed of chlorogenic acid and vanillin. LCP-CE, LCP-25PF and LCP-50PF interacted with locust bean gum/polyvinyl alcohol matrix through hydrogen bonds, thereby improving the light and oxygen barrier ability, tensile strength, thermal stability, antioxidant activity and antimicrobial activity of the film. The film containing LCP-25PF showed the lowest water vapor permeability (10.36 × 10^-11 g m^-1 s^-1 Pa^-1) and oxygen permeability (0.42 cm³ mm m^-2 day^-1 atm^-1) but the highest tensile strength (29.76 MPa), antioxidant activity and antimicrobial activity. In addition, the films containing LCP-CE and LCP-25PF had pH-/ammonia-sensitivity and effectively indicated shrimp freshness at 4 °C. Results suggested the film containing LCP-25PF could be used as smart packaging film.

Chitosan/sulfated locust bean gum nanoparticles: In vitro and in vivo evaluation towards an application in oral immunization

This work proposes the design of nanoparticles based on locus bean gum (LBG) and chitosan to be used as oral immunoadjuvant for vaccination purposes. LBG-based nanoparticles were prepared by mild polyelectrolyte complexation between chitosan (CS) and a synthesized LBG sulfate derivative (LBGS). Morphological characterization suggested that nanoparticles present a solid and compact structure with spherical-like shape. Sizes around 180-200nm and a positive surface charge between +9mV and +14mV were obtained. CS/LBGS nanoparticles did not affect cell viability of Caco-2 cells after 3h and 24h of exposure when tested at concentrations up to 1.0mg/mL. Two model antigens (a particulate acellular extract HE of Salmonella enterica serovar Enteritidis, and ovalbumin as soluble antigen) were associated to CS/LBGS nanoparticles with efficiencies around 26% for ovalbumin and 32% for HE, which resulted in loading capacities up to 12%. The process did not affect the antigenicity of the associated antigens. BALB/c mice were orally immunized with ovalbumin-loaded nanoparticles (100μg), and results indicate an adjuvant effect of the CS/LBGS nanoparticles, eliciting a balanced Th1/Th2 immune response. Thus, CS/LBGS nanoparticles are promising as antigen mucosal delivery strategy, with particular interest for oral administration.

TEMPO-mediated oxidation on galactomannan: Gal/Man ratio and chain flexibility dependence

Guar (GG) and locust bean (LBG) galactomannans (GMs) oxidation at C-6 was performed with catalyst TEMPO, in which the reaction progress was monitored by consume of NaOH solution. The products were characterized by spectroscopic analysis, infrared, and (1)H-nuclear magnetic resonance, confirming the presence of aldehydes groups as intermediate of reaction to carboxylic acid. From high performance anion exchange chromatography with pulsed amperometric detection Man/Gal molar ratio was determined and demonstrated a preference to oxidize Man during the reaction on both GMs, following a first order kinetics of oxidation. The comparative macromolecular behavior of native and oxidized GMs was obtained through the analysis by high performance size exclusion chromatography, and the persistence length (Lp) was 6nm and 4nm to native LBG and GG, respectively. A more accessible OH-6 at mannose residue in LBG could be related with a two times faster reaction than GG. The selective oxidation with catalyst TEMPO proved to be efficient to increase the flexibility of the GMs during oxidation. Short reaction time and β-elimination process were mainly observed to LBG, probably due to a more favorable oxidation access to the polysaccharide main chain.

Taste masked microspheres of ofloxacin: formulation and evaluation of orodispersible tablets

Ofloxacin is a synthetic chemotherapeutic antibiotic used for treatment of a variety of bacterial infections, but therapy suffers from low patients' compliance due to its unpleasant taste. This study was aimed to develop taste masked microspheres of ofloxacin using Eudragit and to prepare orodispersible tablets of the formulated microspheres using natural superdisintegrant. Taste masking Eudragit E100 microspheres were prepared by solvent evaporation technique with an entrapment efficiency ranging from 69.54 ± 1.98 to 86.52 ± 2.25%. DSC revealed no interaction between the drug and polymer. Microspheres prepared at a drug/polymer ratio of 1:4 and 1:5 revealed sufficient flow properties and better taste masking as compared to other ratios. Drug loaded microspheres were formulated as orodispersible tablets using locust bean gum as a natural superdisintegrant offering the advatages of biocompatibility and biodegrad-ability. The wetting time, water absorption ratio and in-vitro disintegration time of the tablets were found to range between 19 ± 2 to 10 ± 3 seconds, 59.11 ± 0.65 to 85.76 ± 0.96 and 22 ± 2 to 10 ± 2 seconds, respectively. The in-vitro ofloxacin release was about 97.25% within 2h. The results obtained from the study suggested the use of eudragit polymer for preparing ofloxacin loaded microspheres with an aim to mask the bitter taste of the drug and furthermore orodispersible tablets could be formulated using locust bean gum as a natural superdisintegrant.

Modifiable natural gum based microgel capsules as sustainable drug delivery systems

Few hundred micrometer size microgel capsules from natural locust bean gum (LBG) was synthesized by means of divinyl sulfone (DVS) crosslinking in a surfactant free cyclohexane medium with 100% yield in 1 h. These LBG microgel capsules were chemically modified with different numbers of linear amine containing modifying agents such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetraamine (TETA) and branched polyethyleneimine (PEI) to induce cationic character for LBG microgels. The biggest change in zeta potential of LBG microgels that is +44.9 mV from -17.67 mV was observed upon the modification of LBG microgels with branched PEI (LBG/PEI). The blood compatibility studies were revealed that bare LBG microgels possess a good blood compatibility with non-hemolytic value, 0.96 ± 0.15%, and high blood clotting index, 87.35 ± 4.10%, whereas the blood compatibility of LBG/PEI microgels was found to be slightly-hemolytic, 4.96 ± 1.03%, and also moderate blood clotting index, 65.98 ± 98%. Additionally, sodium diclofenac (SDC) as a model drug was loaded into the LBG based microgels by directly loading from solution (absorption) and by chemical conjugation methods for in vitro release studies at physiological conditions, pH 7.4 at 37.5 °C A longer, and sustainable drug release profiles were obtained from chemical drug conjugated LBG microgels and the amine modified LBG microgels.

Allicin functionalized locust bean gum nanoparticles for improved therapeutic efficacy: An in silico, in vitro and in vivo approach

The field of nanotechnology has overgrown over the past few years and has even ventured into the field of medicine. The aim of the present study is to develop a novel allicin functionalized locust bean gum nanoparticle using the nanoprecipitation technique. The synthesized nanoparticles were characterized by dynamic light scattering, scanning electron microscopy and transmission electron microscopy. The characterization study revealed the nanoscale structure (∼100nm) of the prepared particles. In silico toxicology analysis were carried out to assess the drug-like properties and virtual toxicity of allicin. Toxicity of the prepared nanoparticles were carried out in RAW 264.7 cell lines in vitro and in vivo studies were carried out in Sprague-Dawley rats. In in vitro study, LBGAN showed a maximum toxicity of 10.51% in MTT assay, no reactive oxygen species generation on DCFDA staining and LBGAN was effective to protect the cells from apoptosis. In in vivo toxicity studies LBGAN showed no significant change in the activities of the marker enzymes like LDH, CK-MB, ALP, ACP, AST and ALT. Thus, the functionalization of nanoparticles with allicin has the benefit of providing protection and stability to the allicin, in addition to increasing its pharmacological activity.

Evaluation of natural gum-based cryogels for soft tissue engineering

In this study, three natural biomaterials, Locust bean gum (LBG), Xanthan gum (XG), and Mastic gum (MG), were combined to form cryogel scaffolds. Thermal and chemical characterizations revealed the successful blend formation from LBG-XG (LX) and LBG-XG-MG (LXM) polymers. All blends resulted in macro-porous scaffolds with interconnected pore structures under the size of 400 μm. The swollen cryogels had similar mechanical properties compared with other polysaccharide-based cryogels. The mean tensile and compressive modulus values of the wet cryogels were in the range of 3.5-11.6 kPa and 82-398 kPa, respectively. The sustained release of the small molecule Kartogenin from varying concentrations and ratios of cryogels was in between 32 and 66% through 21 days of incubation. Physical, mechanical, and chemical properties make LX and LXM polysaccharide-based cryogels promising candidates for cartilage and other soft tissue engineering, and drug delivery applications.

Properties of galactomannans and their textile-related applications-A concise review

Galactomannans are reserve carbohydrates in legume plants and are primarily extracted from their seeds. They contain galactose side chains throughout the mannose backbone and have unique features such as emulsifying, thickening, and gelling together with biodegradability, biocompatibility, and non-toxicity, which make them an appealing material. Guar gum and locust bean gum mainly are used in all galactomannan needed applications. Nonetheless, tara gum and fenugreek gum have also attracted considerable attention in recent decades. Despite the increased usage of galactomannans in the textile-related fields in recent years, there is no review article published yet. To fill this gap and to demonstrate the striking and increasing importance of galactomannans, a concise summary of the properties of common galactomannans and their comparisons is given first, followed by an account of recent developments and applications of galactomannans in the textile-related fields. The associated potential opportunities are also provided at the end of this review.

Quality of casein based Mozzarella cheese analogue as affected by stabilizer blends

Suitability of xanthan gum (XG)-locust bean gum (LBG), carrageenan (CAR)-LBG, and XG-CAR in 1:1 proportion at 0.42% in the formulation was assessed in the manufacture of Mozzarella cheese analogue. The stabilizer blends did not significantly influence the composition, texture profile, organoleptic, baking qualities and pizza-related characteristics of cheese analogues. Considering the influence of stabilizer blend on the sensory quality of analogue and sensory rating of pizza pie, XG-LBG blend (1:1) was preferred over XG-CAR and CAR-LBG.

Effects of locust bean gum on the structural and rheological properties of resistant corn starch

In this study, interactions between resistant corn starch (RS) (5% w/w) and locust bean gum (LBG) (0, 0.125, 0.25, 0.50 and 1.0% w/v) on the viscoelastic, pasting and morphological characteristics of aqueous dispersions were evaluated. Results showed that the storage modulus (G'), loss modulus (G''), and apparent viscosity values of starch/gum (RS/LBG) mixtures were enhanced with the addition of LBG, and the rheograms demonstrated a biphasic behavior. RS/LBG samples were predominantly either solid like (G' > G'') or viscous (G'' > G'), depending on the added concentration level of LBG. Gum addition also caused higher peak viscosity, breakdown and total set back of RS/LBG mixtures. A strong correlation between rheological and structural properties was found. Confocal laser scanning microscopy (CLSM) images confirmed the transition of starch particles from a scattered angular shape to clustered structures cross-linked by dense aggregate junction zones justifying the observed changes in rheological properties.

Efficient expression of a novel thermophilic fungal β-mannosidase from Lichtheimia ramosa with broad-range pH stability and its synergistic hydrolysis of locust bean gum

β-Mannosidase (EC 3.2.1.25) is an exoglycosidase specific for the hydrolysis of terminal β-1,4-glycosidic linkage in mannan which can be applied in the food manufacture, animal feed, bioethanol making and coffee extraction industries. A novel β-mannosidase gene (Lrman5A) from Lichtheimia ramosa was synthesized and recombinantly expressed in Pichia pastoris X33. Lrman5A encodes 444 amino acids with a calculated molecular mass of 51.0 kDa which shares the highest identity (73%) with the β-mannosidase from Rhizomucor miehei. Purified recombinant Lrman5A showed the maximal activity at pH 6.0 and 65°C, had broad-range pH stability (retaining >65% activity after incubation at pH 3.0-8.5 at 37°C for 24 h), and was highly thermostable (retaining >80% activity after incubation at 65°C for 10 min). The specific activity, and K_m of Lrman5A was 17.5 U/mg and 1.377 mM, respectively. Lrman5A and GH5 β-mannanase displayed significant synergistic effects on the degradation of locust bean gum (LBG) and released more mannose (up to 2.89 folds) by simultaneous or sequential addition. Due to its hydrolytic properties, Lrman5A may have potential applications in the area of bioenergy, feed and food processing.

Characterization of hydrophobic interaction of galactomannan in aqueous solutions using fluorescence-based technique

Fluorescence probing was used to study hydrophobic interactions of galactomannan (GM) obtained from fenugreek gum (FG), guar gum (GG), and locust bean gum (LBG) at different M/G ratios. The I₁/I₃ ratio of pyrene changed from 1.73 to 1.29, 1.22, and 1.29 for FG, GG and LBG, respectively, as the concentration of GM increased from 0.01 to 8.0 g/L at 30 °C. The critical aggregation concentration of FG, GG, and LBG increased from 1.04 to 3.84 g/L, 1.15 to 3.73 g/L, and 0.94 to 3.63 g/L, respectively, as temperature increased from 10 to 70 °C. Addition of Na₂SO₄ and NaSCN increased the I₁/I₃ ratio in dilute solution, but reduced it in semi-dilute solution, whereas adding urea reduced I₁/I₃ in dilute solution but increased it in semi-dilute solution. These results indicated that the CAC of GM, polarity and number of hydrophobic microdomains were highly dependent on the M/G ratio and galactose distribution.

Hydrophobized cellulose nanocrystals enhance xanthan and locust bean gum network properties in gels and emulsions

Locust bean/xanthan gum (LBG/XG) synergistic networks have previously been well studied, with evidence that junction zones between the two polymers result in hydrophobic domains. Here we report on the effect of both hydrophilic and hydrophobic cellulose nanocrystals (CNCs) on the rheological properties of the individual gums, the gum networks, and emulsion gels consisting of the gum network and corn oil. We also take advantage of differences in the autofluorescent spectra for each of the components to map their distribution within the gel and emulsion gel systems. Whilst both types of CNC confer thermal stability to the systems, hydrophilic CNCs induce minor changes in rheological properties of synergistic gels and prove to be detrimental to the stability of the emulsion gels. In contrast, hydrophobic CNCs associate with the LBG/XG network, affecting the rheological response. Their inclusion in the emulsion gel system results in smaller, more homogeneously distributed oil droplets with a resultant increase in the storage modulus by an order of magnitude compared to the CNC-free and hydrophilic CNC systems. We conclude that hydrophobic CNCs play a critical role in stabilising LBG/XG network gels and emulsions.

Locust bean gum as an alternative polymeric coating for embryonic stem cell culture

Pluripotent embryonic stem cells (ESCs) have self-renewal capacity and the potential to differentiate into any cellular type depending on specific cues (pluripotency) and, therefore, have become a vibrant research area in the biomedical field. ESCs are usually cultured in gelatin or on top of a monolayer of feeder cells such as mitotically inactivated mouse embryonic fibroblasts (MEFsi). The latter is the gold standard support to maintain the ESCs in the pluripotent state. Examples of versatile, non-animal derived and inexpensive materials that are able to support pluripotent ESCs are limited. Therefore, our aim was to find a biomaterial able to support ESC growth in a pluripotent state avoiding laborious and time consuming parallel culture of MEFsi and as simple to handle as gelatin. Many of the new biomaterials used to develop stem cell microenvironments are using natural polymers adsorbed or covalently attached to the surface to improve the biocompatibility of synthetic polymers. Locust beam gum (LBG) is a natural, edible polymer, which has a wide range of potential applications in different fields, such as food and pharmaceutical industry, due to its biocompatibility, adhesiveness and thickening properties. The present work brings a natural system based on the use of LBG as a coating for ESC culture. Undifferentiated mouse ESCs were cultured on commercially available LBG to evaluate its potential in maintaining pluripotent ESCs. In terms of morphology, ESC colonies in LBG presented the regular dome shape with bright borders, similar to the colonies obtained in co-cultures with MEFsi and characteristic of pluripotent ESC colonies. In short-term cultures, ESC proliferation in LBG coating was similar to ESC cultured in gelatin and the cells maintained their viability. The activity of alkaline phosphatase and Nanog, Sox2 and Oct4 expression of mouse ESCs cultured in LBG were comparable or in some cases higher than in ESCs cultured in gelatin. An in vitro differentiation assay revealed that mouse ESCs cultured in LBG preserve their tri-lineage differentiation capacity. In conclusion, our data indicate that LBG coating promotes mouse ESC growth in an undifferentiated state demonstrating to be a viable, non-animal derived alternative to gelatin to support pluripotent mouse ESCs in culture.

Rheological and kinetic study of the ultrasonic degradation of locust bean gum in aqueous saline and salt-free solutions

The ultrasonic degradation of locust bean gum (LBG) in aqueous solutions has been studied at 25°C for ultrasonication times up to 120 min. Although LBG is not a polyelectrolyte, the degradation extent and kinetics were found to be somewhat sensitive to the ionic conditions in solution, and this is attributed to changes in molecular conformation that can occur in different salt environments. Ultrasonic degradation was tracked by rheological measurements that lead to the determination of intrinsic viscosity for the LBG molecules. A kinetic model was also developed and successfully applied to characterize and predict the degradation results.

Pasting properties of Tamarind (Tamarindus indica) kernel powder in the presence of Xanthan, Carboxymethylcellulose and Locust bean gum in comparison to Rice and Potato flour

Effects of addition of different levels of gums (xanthan, carboxymethylcellulose and locust bean gum) on the pasting properties of tamarind kernel, potato and rice flour were studied by using Rapid Visco-Analyzer (RVA). Tamarind kernel powder (TKP) varied significantly (P < 0.05) from rice and potato flours with respect to its highest protein, ash and fat contents. The results of RVA analysis indicated that pasting properties of flour/gum mixtures were dependent upon the concentration and type of the gums. Peak, breakdown and final viscosity increased with increase in gum concentration in the flour/gum mixture, but the effect was more pronounced for rice and potato flour than for TKP which showed much lower viscosity responses to all of the gums. Among the three gums studied, the increase in viscosity was significantly higher with addition of locust bean gum followed by xanthan while the lowest was observed with carboxymethylcellulose.