Increasing Glycerol Concentration Research Articles

Mechanical and Barrier Properties of Potato Protein Isolate-Based Films

Potato protein isolate (PPI) was studied as a source for bio-based polymer films. The objective of this study was the determination of the packaging-relevant properties, including the mechanical properties and barrier performance, of casted potato protein films. Furthermore, the films were analyzed for cross-linking properties depending on the plasticizer concentration, and compared with whey protein isolate (WPI)-based films. Swelling tests and water sorption isotherm measurements were performed to determine the degree of swelling, the degree of cross-linking, and the cross-linking density using the Flory–Rehner approach. The effects of different plasticizer types and contents on compatibility with potato protein were studied. Glycerol was the most compatible plasticizer, as it was the only plasticizer providing flexible standalone films in the investigated concentration range after three weeks of storage. Results indicated that increasing glycerol content led to decreasing cross-linking, which correlated in an inversely proportional manner to the swelling behavior. A correlation between cross-linking and functional properties was also reflected in mechanical and barrier characterization. An increasing number of cross-links resulted in higher tensile strength and Young’s modulus, whereas elongation was unexpectedly not affected. Similarly, barrier performance was significantly improved with increasing cross-linking. The overall superior functional properties of whey protein-based films were mainly ascribed to their higher percentage of cross-links. This was primarily attributed to a lower total cysteine content of PPI (1.6 g/16 g·N) compared to WPI (2.8 g/16 g·N), and the significant lower solubility of potato protein isolate in water at pH 7.0 (48.1%), which was half that of whey protein isolate (96%). Comparing on an identical glycerol level (66.7% (w/w protein)), the performance of potato protein isolate was about 80% that of whey protein isolate regarding cross-linking, as well as mechanical and barrier properties.

Study of tensiometric properties, microbiological and collagen content in nile tilapia skin submitted to different sterilization methods.

Tissue bioengineering development is a global concern and different materials are studied and created to be safe, effective and with low cost. Nile Tilapia skin had shown its biological potential as covers for the burn wound. This study evaluates the tilapia skin histological, collagen properties and tensiometric resistance, after treatment by different sterilization methods. Tilapia skin samples were submitted to two sterilization processes: (1) chemical, which consisted in two 2% chlorhexidin baths, followed by sequential baths in increasing glycerol concentrations; and (2) radiation, when glycerolized skin samples were submitted to gamma radiation at 25, 30 and 50kGy. Microscopic analyzes were performed through Haematoxylin-eosin and Picrosirius Red under polarized light. For tensiometric analysis, traction tests were performed. Glycerol treated skin presented a discrete collagen fibers disorganization within the deep dermis, while irradiated skin did not show any additional change. Throughout the steps of chemical sterilization, there was a higher proportion of collagen with red/yellow birefringence (type I) in the skin samples up to the first bath in chlorhexidin, when compared to samples after the first two glycerol baths (P<0.005). However, there was no difference in relation to total collagen between groups. In irradiated skin, there was a larger total collagen preservation when using until 30kGy (P<0.005). Tensiometric evaluation did not show significant differences in relation to maximum load in the groups studied. We concluded that chemical and radiation (25 and 30kGy) are efficient methods to sterilize Nile Tilapia skin without altering its microscopic or tensiometric characteristics.

Assessment of glycerol usage by five different purple non-sulfur bacterial strains for bioplastic production

Five purple bacterial strains were investigated by sequencing the 16S rDNA gene and by screening the strains for glycerol usage. The screening was carried out in order to identify the bacterial capacity to consume glycerol. Of the five examined, only three strains metabolized glycerol. A controlled cylindrical photobioreactor was operated in batch mode for testing the substrate consumption. A combination of glucose and glycerol was also used to increase the glycerol consumption rate (GCR). Using Rhodopseudomonas sp. S16-VOGS3, the highest GCR of 14.0 mg/L h was obtained. This most suitable bacteria (Rhodopseudomonas sp. S16-VOGS3) was next grown at two consecutive growth-steps: the first, under a standard batch-growth condition; the second was carried out under fed-batch growth mode, after having removed the exhausted medium and replaced it with a fresh one deprived of Nitrogen and Sulphur nutrients. The fed-batch growth mode caused a significant increase of glycerol concentration ( >6.0 g/L) in the medium, which decreased when the glycerol addition was stopped. The Nitrogen and Sulphur starvation condition caused a stress in Rhodopseudomonas cells, which stimulated poly-3-hydroxybutyrate accumulation. During both steps, no bioH2 was produced. Nevertheless, when the bacterium was tested under nutrient starvation, the poly-3-hydroxybutyrate content increased by up to 18%, demonstrating that a degradable plastic material could be efficiently produced with the aforementioned two-step procedure. In conclusion, Rhodopseudomonas sp. S16-VOGS3 is a potential candidate for employing crude glycerol coming from biodiesel industry, as a suitable feedstock for the production of degradable products such as bioplastics.

Effect of glycerol, nanoclay and graphene oxide on physicochemical properties of biodegradable nanocellulose plastic sourced from banana pseudo-stem

Banana pseudo-stems, as agricultural waste, are a potential source of ecofriendly nanocellulose-based biodegradable plastic. In this research, effect of glycerol as a plasticiser and nanoclay (NC), and graphene oxide (GO) as nanofillers on the banana pseudo-stem nanocellulose film mechanical, morphological, chemical, thermal, and barrier properties were studied extensively. NC and GO were found to be able to improve the tensile strength of the films but not their elasticity. These nano-fillers also increased the contact angle of the films. On the other hand, glycerol, which acted as a plasticiser, increased the elasticity of the films, but reduced the thermal stability, tensile strength, and contact angle. Synergetic effects were observed when nanofillers and glycerol were combined; both tensile strength and elasticity were improved and the contact angle of the films was significantly higher than films that only contained nanofillers. Concentration of plasticiser had significant effect on the film barrier properties. The water vapor permeability was positively correlated to the glycerol concentration. In contrast, oxygen permeability decreased as increase in glycerol concentration. These results strongly indicate that the properties of the banana pseudo-stem nanocellulose film could be engineered by modifying the type and concentration of added additives. This finding also provides fundamental knowledge and strategy options to further improve nanocellulose based bioplastic.

Glycerol-controlled synthesis of MoS2 hierarchical architectures with well-tailored subunits and enhanced electrochemical performance for lithium ion batteries

MoS2 threedimensional (3D) architectures with various subunits were synthesized using glycerol to mediate the growth of MoS2 crystals though a CS2-assisted hydrothermal approach. It has been found that the thickness and lateral size of subunits can be distinctly reduced by increasing glycerol content in the mixture solvent. A stable porous MoS2 architecture, composed of nanosheets with a tiny size, ∼3 layers and expanded interlayer distance, namely MoS2-15, was obtained when the volume proportion of glycerol reaches 15%. The sample MoS2-15 exhibits superior electrochemical performance in lithium ion storage, due to reasonable design as well as smart organization of MoS2 subunits, featured by a capacity of 1027 mAh g−1 at 0.1 A g−1 after 100 cycles and 738 mAh g−1 at 5 A g−1 after 300 cycles, exceeding other MoS2 nanostructured materials in this work. More importantly, the as-prepared various architectures exhibit tunable electrochemical behaviors depending on structure and morphology evolution, which truly reflects the potential to optimize the microstructure for lithium-ion host materials.

Comparison of DNA fragmentation of frozen-thawed epididymal sperm of dogs using Sperm Chromatin Structure Analysis and Sperm Chromatin Dispersion test

The aim of this study was to compare sperm DNA fragmentation of frozen-thawed epididymal sperm of dogs using the SCSA (Sperm Chromatin Structure Assay) and SCDt (Sperm Chromatin Dispersion test). For this purpose, epididymis from neutered dogs were minced and incubated in a Tris-based extender. The recovered sperm were frozen in a two-step cooling protocol with Tris-based, egg yolk extender and increasing glycerol concentrations, and stored in liquid nitrogen. After thawing, each replica was incubated at 38 °C for 24 h. Sperm DNA fragmentation index (sDFi) was assessed by SCSA and SCDt at 0, 3, 6 and 24 h of incubation and compared within treatments. The relationship and agreement between techniques were evaluated by Pearson’s coefficient and Intraclass Correlation Coefficient (ICC). The results were expressed as mean ± standard error of the mean (SEM). Both techniques indicated there was a significant increase of DNA fragmentation after 24 h of incubation. Moderate correlation (r = 0.65; P<0.01) but lack of agreement (ICC = 0.451; P>0.05) was found between SCSA and SCDt. The lack of agreement indicates that SCSA and SCDt measure different aspects of DNA fragmentation. Four halo morphologies were detected after 24 h of incubation using the SCDt: un-fragmented DNA with a small halo, fragmented DNA with large halo and two new halo presentations never described before for dog sperm: receding sperm with a disappearing halo and “bald” sperm without chromatin dispersion halo around the core. Sperm without a halo of chromatin dispersion are not described by the manufacturer and are similar to un-fragmented sperm, which could lead to erroneous results when using the SCDt. Further studies with different incubation periods and including the new morphologies described in this study should be performed. In conclusion, although SCSA and SCDt can evaluate the changes in the sperm DNA fragmentation dynamics of frozen-thawed epididymal dog sperm, these provided different findings on sperm DNA fragmentation.

Surface modification of thin film composite reverse osmosis membrane by glycerol assisted oxidation with sodium hypochlorite

Need for improvement in water flux of thin film composite (TFC) RO membrane has been appreciated by researchers world over and surface modification approach is found promising to achieve higher water flux and solute rejection. Thin film composite RO membrane was exposed to 2000mg/l sodium hypochlorite solution with varying concentrations of glycerol ranging from 1 to 10%. It was found that there was a drop in concentration of sodium hypochlorite after the addition of glycerol because of a new compound resulted from the oxidation of glycerol with sodium hypochlorite. The water flux of the membrane treated with 1% glycerol with 2000mg/l sodium hypochlorite for 1h was about 22% more and salt rejection was 1.36% greater than that of only sodium hypochlorite treated membrane for the same concentration and time. There was an increase in salt rejection of membrane with increase in concentration of glycerol from 1% to 5%, however, increasing glycerol concentration further up to 10%, the salt rejection declined. The water flux was found declining from 1% glycerol solution to 10% glycerol solution. The membrane samples were characterized to understand the change in chemical structure and morphology of the membrane.

Insight into Influence of Glycerol on Preparing α-CaSO4·1/2H2O from Flue Gas Desulfurization Gypsum in Glycerol–Water Solutions with Succinic Acid and NaCl

The conversion of CaSO4·2H2O (DH) to CaSO4·1/2H2O (HH) was facilitated by increasing glycerol content from 55% to 85% in glycerol–water mixtures; the average length and diameter of produced α-HH crystals decreased from 60.97 to 7.21 μm and from 15.21 to 5.17 μm, respectively, resulting in a decrease in the average aspect ratio from 4.06 to 1.41. The phase transformation was reduced dramatically from 30 to 3 h. As glycerol content increased in the mixtures, an increase in α-HH maximal relative supersaturation and decrease of ion diffusion rate were hypothesized as explanations for the morphology change in the alpha-hemihydrate (α-HH) produced. The kinematic feasibility of FGD gypsum transition to α-HH in the mixed solutions with the increase of glycerol should also be attributed to the enhancement of maximal relative supersaturation for α-HH precipitation.

Chitosan membrane dressings toughened by glycerol to load antibacterial drugs for wound healing

Transparent and flexible chitosan-based membranes containing antibacterial drugs were prepared through a casting/solvent evaporation method from suspension of chitosan floccule. To enhance mechanical properties, glycerin was incorporated into the floccule suspension to conjugate chitosan as a plasticizer. The mechanism of membrane formation is attributed to inter- and intro-hydrogen bonding between chitosan and glycerol molecules. The results showed that incorporation of glycerol has a significant influence on the properties of the chitosan membranes. With the increase of glycerol content, the tensile strength, swelling rate, water vapor permeability and wettability of membranes were significantly improved. In vitro enzymatic degradation revealed that the chitosan membrane had long-term stability regardless of the glycerol content. To enhance antibacterial properties, tetracycline hydrochloride (TH) and silver sulfadiazine (AgSD), representing the water-soluble and water-insoluble drug models, were integrated into the membranes, respectively. The results of controlled-release efficacy and inhibition zone indicate that the glycerol toughened chitosan membranes containing drugs have a promising future in treatment of bacterial infection as wound dressing.

489 Effects of the inclusion of linseed and increasing concentrations of glycerol as replacement of corn grain on rumen fermentation, methane production and nutrient disappearance in a rusitec system

The aim of the study was to assess the effects of using linseed and increasing concentrations of glycerol in a forage diet supplemented with corn grain on nutrient disappearance, methane (CH4) production and fermentation parameters in a Rusitec fermentation system. The experimental diets were: control, (70% ryegrass/clover mixed hay, 30% corn grain); positive control (70% hay, 15% corn grain, 15% linseed); 5% glycerol (70% hay, 10% corn grain, 15% linseed, 5% glycerol); 10% glycerol (70% hay, 5% corn grain, 15% linseed, 10% glycerol). The experiment was a complete randomized design with the four dietary treatments with 2 replicates in an 8 fermenter Rusitec apparatus. Incubations were run twice during 15d. The first 10d were used for fermenter adaptation, followed by 5d of sampling (days 11 to 15). The individual fermenter was the experimental unit. The model included the fixed effects of diet, day and diet/day interactions with the day of sampling from each fermenter treated as a repeated measure. Total VFA concentrations in effluent were increased (P = 0.005) in the glycerol added diets as compared to positive control. Acetate concentrations were reduced with increasing glycerol concentration in diets whereas propionate increased with linseed inclusion. Increasing concentrations of glycerol resulted in further increased propionate concentrations (P < 0.001), thus leading to important reductions in the acetate/propionate ratio. However, CH4 production (mgCH4/g DM digested) was reduced by linseed inclusion in the diet (P = 0.004) but not by increasing concentrations of glycerol in the diet. Ammonia nitrogen was increased in all linseed supplemented diets (P < 0.001). Total DM and non-fibrous carbohydrates in vitro disappearance were not affected by dietary treatments (P = 0.411). However, CP and EE disappearance were increased in linseed supplemented diets (P < 0.001) but not further affected by glycerol inclusion. Disappearance of NDF was increased only in the positive control diet as compared to control diet (P = 0.0185). In conclusion, the use of linseed as replacement of corn grain reduces CH4 production in a Rusitec system but increases ammonia nitrogen. Increased propionate concentrations in glycerol supplemented fermenters does not result in reduced CH4 production despite increases in propionate concentrations. Linseed inclusion increases in vitro disappearance of CP and EE without affecting total DM disappearance.

Chemical, Physical, and Barrier Properties of Edible Film from Flaxseed Mucilage

Chemical, physical, and barrier properties of flaxseed mucilage-based films were investigated to determine the appropriate applications for coating or packaging of food or bioproducts. The film samples were formed via casting with the addition of glycerol as a plasticizer up to a maximum of 5 wt.%. Fourier transform infrared (FTIR) spectra showed an increase of intensity in the –OH stretching vibration region and the appearance of a new peak at 2883.1 cm-1 in the plasticized film samples. These changes may indicate possible interactions between the mucilage and glycerol. With increasing glycerol concentration, the water activity decreased, while the moisture content and water solubility increased. With regard to barrier properties, the water vapour permeability (WVP) and oxygen permeability (OP) notably increased with increasing glycerol content. With these high WVP and OP values, the films can be potentially extended for coating or packaging fresh produce.

THE EFFECT OF GLYCEROL CONTENT ON MECHANICAL PROPERTIES, SURFACE MORPHOLOGY AND WATER ABSORPTION OF THERMOPLASTIC FILMS FROM TACCA LEONTOPETALOIDES STARCH

Tacca leontopetaloides is a new plant source of starch and has high potential to produce film of thermoplastic. In this study, thermoplastic starch (TPS) derived from T.leontopetaloides was developed with glycerol as plasticizer through casting method at temperature range from 85 °C to 90 °C and enhanced with sulphur vulcanization method. It was found that the addition of 5%, 10%, 15%, 20% and 25% (v/v) of glycerol into T.leontopetaloides starch had affected the mechanical properties, surface morphology, and water absorption of the thermoplastic films. In the mechanical properties study, the TPS films have the highest tensile strength (47.96 MPa) at 5% glycerol content in the formulation. Conversely, the TPS films have increasing value of elongation at break (EAB) with increasing glycerol concentration with the higher EAB obtained at 25% glycerol content (52.90%). The morphology of thermoplastic film was examined by using Scanning Electron Microscopy (SEM). As glycerol content increased, thermoplastic films showed smoother surface, homogenous and good distribution. In water absorption test, TPS films showed lower affinity to water absorption at lower glycerol content. The weight of the TPS films increased ranging from 80.3% to 107.4% after 12 hour of immersion in water. It can be concluded that, glycerol significantly affected the properties of TPS film within the range of glycerol concentration studied.

Bioplastics of Native Starches Reinforced with Passion Fruit Peel

Industrial passion fruit juice production generates a large amount of passion fruit waste, which contains about 60% of fibers when dried and could be used as reinforcement of thermoplastic starch. This study aimed to develop an extruded starchy bioplastic reinforced with passion fruit peel (Pfp) (0, 4, 10, 16, and 20%), glycerol (60, 64, 70, 76, and 80 wt%), and starch mix (55% corn and 45% cassava) that were processed at varied screw speeds (66, 80, 100, 120, and 134 rpm). The response surface methodology was applied to analyze the effects of Pfp, glycerol, and screw speed. Mechanical properties, contact angle, and water permeability and solubility were the response variables. Addition of Pfp, up to 4%, improved the bioplastic mechanical properties. High addition of Pfp (16 and 20%) combined with the lowest screw speed (66 rpm) reduced bioplastic water solubility. Water vapor permeability slightly increased with the combination of increasing glycerol content and screw speed. Contact angle was not statically affected by the independent variables. The extrusion showed as an interesting tool that provided greater homogeneity of Pfp incorporated in starch bioplastic, though the mix would benefit from finer Pfp particle size distribution.

Combustion of hydrogen–oxygen microfoam on the water base

On the basis of experimental study the paper analyzes the process of combustion wave propagation in the hydrogen–oxygen microfoam on the water base. Combustible microfoam consists of gaseous bubbles dispersed in the water solution of surfactant. Bubbles contain hydrogen and oxygen and their diameters are in the range from 60 to 230 μm. Expansion ratio of the combustible foam is in the range from 8 to 22. The paper establishes the influence of surfactant concentration, glycerol concentration, tube diameter and Shchelkin's spiral on the speed of flame propagation in the foam. It is shown that for considered range of regime parameters the characteristic mode of flame propagation in the semi-opened tube is the accelerated mode. The increase in glycerol content leads to the increase in flame speed. However after certain critical concentration of glycerol the foam loses the ability to burn. Total burning rate depends on surfactant concentration non-monotonically with characteristic maximum. Shchelkin's spiral installed at inner surface of the tube as well as the decrease in tube diameter favor flame deceleration.

Neu1 sialidase interacts with perilipin 1 on lipid droplets and inhibits lipolysis in 3T3-L1 adipocytes.

Fatty acids are stored within adipocytes in lipid droplets (LDs) as triacylglycerol (TG), which is converted to free fatty acid (FFA) and glycerol via lipolysis. Increased plasma FFA levels in obesity are associated with several clinical conditions. We previously found that Neu1 activity is aberrant in the epididymal fat and liver of obese and diabetic mice. Here, we examined involvement of Neu1 in lipolysis in 3T3-L1 adipocytes. Small interfering RNA against Neu1 was introduced into adipocytes, and glycerol concentrations were measured in the culture medium. We then assessed the effects of Neu1 knockdown on lipolytic protein expression and phosphorylation, as well as interactions between perilipin 1 (Plin1) and hormone-sensitive lipase (HSL) after isoproterenol (IS) stimulation. Interactions between Neu1 and Plin1 were analyzed by immunoprecipitation and immunofluorescent imaging using adipocytes transfected with pCMV6-mNeu1-myc-DYKDDDDK (mNeu1DDK). Neu1 knockdown increased glycerol concentrations in culture media and Plin1 phosphorylation in whole lysates of IS-stimulated cells. Neu1 knockdown increased interaction between Plin1 and HSL after IS stimulation whereas that between Neu1 and Plin1 on LD observed under basal conditions was lost. These results suggest that Neu1 inhibits lipolysis induced by β-adrenergic stimulation in adipocytes via interactions with Plin1 on LD.

Effect of Glycerol on the Properties of Tapioca Starch Film

Biodegradable films from tapioca starch (TPS) were formed by tape casting. The impact of glycerol (0, 5, 10, 15 and 20%) on the mechanical properties was investigated. The increase in glycerol content reduces the tensile strength while increasing the elongation at break. The varying concentrations of glycerol led to changes in tapioca starch edible film properties, potentially affecting film performances. The merging and increase in the intensity of absorption between 3700-3300 cm-1 as a result of increase in glycerol proportion is due to possible interaction of the OH groups in TPS and glycerol thereby increasing intermolecular H-bond.

Molecular and biochemical characterization of dimethachlone resistant isolates of Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a necrotrophic fungal plant pathogen with a broad host range. The dicarboximide fungicide dimethachlone has been used to control this pathogen for more than a decade and resistance to dimethachlone has recently been reported in China. Compared with sensitive isolates, the three dimethachlone resistant isolates with resistance ratios of 78.3, 85.5, and 94.8 exhibited significantly (P<0.05) higher cell membrane permeability and peroxidase and polyphenol oxidase activities. Dimethachlone at 0.25μg/mL significantly increased cell membrane permeability and enhanced activity of the two enzymes in both resistant and sensitive isolates. There were no significant differences in glycerol or oxalate content between the resistant and sensitive isolates. Dimethachlone treatment increased glycerol content in the resistant isolates and reduced in the sensitive isolates (P<0.01). Sequencing of three genes involved in two-component signal pathway and of three genes in mitogen-activated protein (MAP) kinase cascade demonstrated that the dimethachlone resistant isolates HLJ4 and HLJ6 harbored point mutations of I232T and G1087D, respectively, in the deduce amino acid sequence of the histidine kinase (HK) gene Sshk. HLJ4 had a point mutation of P96L in the deduced amino acid sequence of the MAP kinase-kinase gene SsPbs. The expression levels of the Sshk gene were higher in HLJ4 and HLJ6 than in HLJ3 and the sensitive isolate HLJMG2, and transcription of the Sshk gene was up-regulated by dimethachlone for the three resistant isolates.

Glycerol stress in Saccharomyces cerevisiae: Cellular responses and evolved adaptations.

Glycerol synthesis is key to central metabolism and stress biology in Saccharomyces cerevisiae, yet the cellular adjustments needed to respond and adapt to glycerol stress are little understood. Here, we determined impacts of acute and chronic exposures to glycerol stress in S. cerevisiae. Glycerol stress can result from an increase of glycerol concentration in the medium due to the S. cerevisiae fermenting activity or other metabolic activities. Acute glycerol-stress led to a 50% decline in growth rate and altered transcription of more than 40% of genes. The increased genetic diversity in S. cerevisiae population, which had evolved in the standard nutrient medium for hundreds of generations, led to an increase in growth rate and altered transcriptome when such population was transferred to stressful media containing a high concentration of glycerol; 0.41 M (0.990 water activity). Evolution of S. cerevisiae populations during a 10-day period in the glycerol-containing medium led to transcriptome changes and readjustments to improve control of glycerol flux across the membrane, regulation of cell cycle, and more robust stress response; and a remarkable increase of growth rate under glycerol stress. Most of the observed regulatory changes arose in duplicated genes. These findings elucidate the physiological mechanisms, which underlie glycerol-stress response, and longer-term adaptations, in S. cerevisiae; they also have implications for enigmatic aspects of the ecology of this otherwise well-characterized yeast.

Water Vapor Permeability of Edible Films Based on Improved Cassava (Manihot esculenta Crantz) Native Starches

Starch is used in the production of edible biodegradable packaging as an attractive alternative to synthetic polymers because it is a natural biopolymer of low cost and high availability. Many studies have been carried out on films based on cassava starch and the results show that these have good flexibility and low water vapor permeability. This present research was conducted to analyse the effect of glycerol, peanut oil and soybean lecithin on the water vapor permeability (WVP) of edible films based on improved cassava (Manihot esculenta Crantz) native starches from Cote d’Ivoire. The films were prepared using 4 g cassava starch, 25% and 30% glycerol (w/w), 5% and 10% peanut oil (w/w) and 0% to 5% soybean lecithin (w/w oil) in Petri dishes. The WVP of the films was determined at 25°C and 75% relative humidity. The moisture content of the films was determined in an oven at 105°C and the film thickness was determined manually using a micrometer. The resulting films were homogeneous, transparent and crack-free. WVP, moisture content and thickness of the films increased with increasing glycerol concentration. Increasing the concentrations of the peanut oil and soybean lecithin decreased the thickness and increased the moisture content of the films. The combination of glycerol and peanut oil increased the WVP of the films, whereas addition of soybean lecithin had no effect. The lowest WVP values were obtained using 25% glycerol, 5% peanut oil and 5% soybean lecithin. Starch obtained from improved cassava varieties cultivated in Cote d’Ivoire can be a potential ingredient in the production of food packaging.

Flexible strength-improved and crack-resistant biocomposites based on plasticised wheat gluten reinforced with a flax-fibre-weave

This paper presents strength-improved and crack-resistant wheat gluten biocomposites, using flax-fibre-weaves as reinforcement. The composites were produced by dip-coating of the weave into a wheat gluten/glycerol (WGG) solution, or by compression moulding. The most extensive coverage and wetting of the flax yarns occurred during the compression moulding, and the adhesion between the fibres and the matrix increased with increasing glycerol content. The compression-moulded sheets were, at a comparable flax content, stiffer than those produced by dipping, whereas their strength was similar and their extensibility slightly lower. Tensile tests on notched samples showed that the flax yarn improved the crack-resistant properties significantly; the maximum stress increased from 2 to 29MPa using a content of 19wt.% flax fibres. A clear advantage of this novel mechanically flexible biocomposite is that it can be shaped plastically under ambient conditions, while at the same time providing in-plane stiffness, strength and crack-resistance.