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To produce textiles that regenerate antimicrobial surfaces wash after wash, we synthesized and immobilized antimicrobial silver nanoparticles (Ag NPs) within brown cotton fibers. This composite for...

Burgundy oil (BO) from Eastern red cedar provides resistance against termites and wood-decay fungi and is enhanced when combined with an amylose inclusion complex (AIC) containing hexadecylammonium chloride (HAC). Indirect evidence also indicated that a methanol Loblolly pine extract (LPE) was inhibitory against termites. This study compared the effects of HAC and didecyldimethylammonium chloride (DDAC) combined with LPE and BO on termites and wood-decay fungi. Southern pine was treated by vacuum/pressure impregnation and resistance evaluated after exposure to termites and decay fungi. The combination of BO and either HAC/AIC or DDAC/AIC reduced wood mass losses by termites, increased termite mortality, and inhibited all wood-decay fungi. The HAC/AIC and DDAC/AIC resulted in equivalent mass losses by termites and termite mortalities. The DDAC was slightly more inhibitory than the HAC against wood-decay fungi. Given the slight advantage of DDAC over HAC and because DDAC is currently used to preserve wood, DDAC might be preferred over HAC. The LPE had a very minor effect on mass loss by termites, termite mortality, and only a slight inhibitory effect on G. trabeum and T. versicolor, while R. placenta and I. lacteus were unaffected. Higher concentrations of DDAC and/or LPE might improve protection against termites and wood-decay fungi.

Viscoelasticity of corn zein is associated with the formation of β-sheet secondary structures; however, studies of the fundamentals of this conformational change are limited due to zein insolubility and poor analytical resolution. Here, changes in soluble zein conformation were evaluated as the protein self-assembles in increasingly hydrophilic solvents to the concentration just before aggregation and precipitation. Circular dichroism spectra of zein showed that α-helix structures decrease in favor of random coil and β-sheets with increases in water content in an ethanol-water system, similar to observations of zein when it becomes viscoelastic in dough systems. This was further supported by changes in Thioflavin T fluorescence emission spectra and intrinsic viscosity measurements. Two widely recognized molecular models for α-zein (hairpin and superhelical conformations) were tested at 75 and 45% ethanol concentration using molecular dynamics simulation for agreement with experimental results. Increase in solvent hydrophilicity increased β-sheets and reduced distance between backbone anomeric carbons only for hairpin model, suggesting it to be the more valid of the two. These findings emphasize the importance of transformation to β-sheets during zein self-assembly and provide further insight into the mechanisms by which the protein is functionalized into viscoelastic systems.

The use essential oils as ecofriendly tools for pest and vector management has become one of the mainstreams for biopesticide research. Here, Commiphora erythraea (opoponax) essential oil and its fractions were profiled for their chemical composition and larvicidal activity against Culex restuans, Cx. pipiens, and Aedes aegypti mosquitoes. The effect of C. erythraea essential oil on expression of three cytochrome P450 (CYP450s) and three Glutathione-S-transferases (GSTs) genes and the use of bio-based amylose-N-1-hexadecylammonium chloride inclusion complex (Hex-Am) and amylose-sodium palmitate inclusion complex (Na-Palm) as emulsifiers for C. erythraea essential oil were also investigated. The most abundant chemical constituents were curzerene (32.6%) in fraction 1, spathulenol (62.5%) in fraction 2, and bicyclosesquiphellandrene in the whole essential oil (33.9%) and factions 3 (30.1%) and 4 (23.8%). LC50 values for the whole essential oil were 19.05 ppm for Cx. restuans, 22.61 ppm for Cx. pipiens and 29.83 ppm for Ae. aegypti and differed significantly from each other. None of the four C. erythraea essential oil fractions were active against mosquito larvae. Two CYP450 genes (CYP6M11 and CYP6N12) and one GST gene (GST-2) were significantly upregulated in Ae. aegypti larvae exposed to C. erythraea essential oil suggesting their potential involvement in pathways of metabolic activation and detoxification of C. erythraea essential oil. Essential oil emulsions produced with Hex-Am were more toxic than the whole essential oil while those produced with Na-Palm had similar toxicity as the whole essential oil. These findings demonstrate that C. erythraea essential oil is a promising source of mosquito larvicide and that its larvicidal activity is likely due to synergistic interactions among the major and minor constituents. The findings also demonstrate that the use of Hex-Am as an emulsifier can enhance the insecticidal properties of C. erythraea essential oil.

Four crop plants known to be hosts for the lepidopteran Trichoplusia ni (soybean, green bean, cotton, and cabbage) were treated with the biopesticide AfMNPV baculovirus in a dosage response assay. Treated soybean had, on average, a 6-fold increase in virus activity compared with the other crops. Leaf trichomes on soybeans were not found to be responsible for the observed increase of insecticidal activity. Three flavonoid compounds (daidzein, genistein, and kaempferol) were uniquely found only in the soybean crop, and were not detected in cotton, cabbage, or green bean plant matter. The individual flavonoid compounds did not cause T ni. mortality in no-virus assays when incorporated into artificial insect diet. The combination of the three flavonoid compounds at leaf level concentrations significantly increased baculovirus activity in diet incorporation assays. When the daidzein, genistein, and kaempferol were added to artificial diet, at 3.5–6.5 × leaf level concentrations, virus activity increased 1.5, 2.3, and 4.2-fold for each respective flavonoid. The soybean flavonoid compounds were found to synergistically improve baculovirus activity against T. ni.

Amylose complexes formed with fatty sodium salts were evaluated for their emulsification, foaming, and rheological properties. Amylose inclusion complexes (AIC) were produced in a pressurized microwave reactor using the sodium salts of fatty acids having carbon chain lengths of 12–22. The AIC were isolated by freeze drying, re-dissolved into aqueous solutions (0.1–3.0% solids) and their surface and rheological properties were then characterized. The AICs successfully formed emulsions with corn oil. The emulsifying properties of the various AIC, as well as long-term emulsion storage stability were determined. The AIC have superior emulsifying activity at neutral and alkaline pH, and superior stability at alkaline pH, compared with commercial octenyl succinic anhydride (OSA) starch. In neutral aqueous solutions, the sodium arachidate (C20) AIC had 31% greater emulsifying activity, and the sodium behenate (C22) AIC had 60% greater emulsion stability than OSA starch. Emulsions formed with the AIC were stable during long-term storage as the oil droplets were resistant to coalescence. Stability increased with fatty acid salt chain length due to viscosity differences, with solutions of the higher molecular weight fatty acid salt AICs having greater viscosity. All AIC emulsions had enhanced emulsifying activity with increased alkalinity of the continuous phase. The AIC are surface active polymeric emulsifiers which did not produce foams. The AIC are effective biodegradable emulsifiers produced from readily available inexpensive food grade ingredients formed via van der Waals rather than chemical bonds.

As a means to alter the physical properties of electrospun zein fibers, plasticizers (glycerol, lactic acid, and oleic acid) or co-proteins (casein, whey protein, rice protein) were mixed with zein using the solvents acetic acid or aqueous ethanol with or without sodium hydroxide. Incorporating plasticizers or co-proteins had a negligible impact on solution viscosity, solution surface tension, and fiber formation, although electron microscopy of fiber mats showed an increase in bead formation with added co-proteins. Gel electrophoresis identified casein and whey protein in spun mats. Infrared spectra demonstrated the inclusion of plasticizers in fiber mats. Glycerol, lactic acid, and oleic acid reduced the glass transition temperature of bulk fibers. Nanoindentation tests of individual fibers found reduced Young's moduli with added lactic or oleic acids but increased moduli with added casein. Thus, electrospinning zein with food-grade plasticizers or proteins physically modifies fibers, yet incorporating significant protein quantities remains a challenge.

Synthetic pesticides are the cornerstone of vector-borne disease control, but alternatives are urgently needed to tackle the growing problem of insecticide resistance and concerns over environmental safety. Leptospermum scoparium J.R. Forst and G. Forst (manuka) essential oil and its four fractions were analyzed for chemical composition and toxicity against Aedes aegypti larvae. The use of bio-based amylose-N-1-hexadecylammonium chloride inclusion complexes (Hex-Am) as an emulsifier for L. scoparium essential oil was also investigated. Fraction 1 was inactive, fractions 2 (LC50 = 12.24 ppm) and 3 (LC50 = 20.58 ppm) were more toxic than the whole essential oil (LC50 = 47.97 ppm), and fraction 4 (LC50 = 35.87 ppm) had similar toxicity as the whole essential oil. Twenty-one chemical constituents were detected in L. scoparium essential oil compared to 16, 5, 19 and 25 chemical constituents in fractions, 1, 2, 3 and 4 respectively. The two most dominant chemical constituents were calamenene (17.78%) and leptospermone (11.86%) for L. scoparium essential oil, calamenene (37.73%) and ledene (10.37%) for fraction 1, leptospermone (56.6%) and isoleptospermone (19.73) for fraction 2, cubenol (24.30%) and caryophyllene oxide (12.38%) for fraction 3, and γ-gurjunene (21.62%) and isoleptospermone (7.88%) for fraction 4. Alpha-pinene, ledene, and aromandendrene were 2-7 times less toxic than the whole essential suggesting that the toxicity of L. scoparium essential oil was either due to other chemical constituents that were not tested or due synergist interactions among chemical constituents. Leptospermum scoparium essential oil-Hex-Am emulsion (LC50 = 29.62) was more toxic than the whole essential oil. These findings suggest that L. scoparium essential oil is a promising source of mosquito larvicide and that Hex-Am is an excellent emulsifier for L. scoparium essential oil for use as a larvicide.

Previous research has shown that zein, above its glass transition temperature, may adopt molecular structures that are able to form doughs with viscoelastic properties comparable to those of wheat gluten. It is hypothesized that extrusion can promote molecular changes in zein and favor interactions with starch that enhance dough viscoelasticity. Thus, the effects of extruding zein at 90–160 °C on the rheological properties of doughs prepared with potato, rice, and maize starches were determined. Formulations were optimized to provide similar mixing profiles to that of a standard wheat dough. For all zein samples, creep-recovery tests demonstrated that doughs prepared with maize and potato starches were less elastic when compared to doughs prepared with rice starch. Zein doughs produced using rice starch were comparable to wheat-dough. Extensional tests showed that zein extruded at 160 °C provided a larger increase in strain-hardening behavior, which is important for bread production. These samples also exhibited larger extensional stresses. Gel electrophoresis of zein extruded at 160 °C revealed an increase in protein aggregates and the presence of smaller peptides when compared to samples subjected at lower extrusion temperatures. Scanning electron micrographs of doughs containing zein showed starch granules embedded within an amorphous material and fibrous structures, which is attributed to elongated zein.

The cationic amylose-hexadecylammonium chloride inclusion complex (Hex-Am) was found to be an effective antifungal treatment for Fusarium sambucinum (Fuckel), a causal agent of potato dry rot. The Hex-Am treatment was effective against F. sambucinum in vitro and in situ, with an effective 50% inhibitory concentration of 400 μg/ml; active component concentration of 20 μg/ml. The amylose complex alone, and blended with polyvinyl alcohol (PVOH), was effective in controlling dry rot in five varieties of potatoes with up to a 99% reduction in damage to the potato tubers. The amylose complex showed no apparent signs of phytotoxicity, with wound periderm reforming within one week of storage at 15 °C and 90% RH. The Hex-Am treatments form an effective antimicrobial film at the wound site, significantly inhibiting fungal damage to the wounded tubers.

Amylose inclusion complexes were prepared from high amylose cornstarch and hexadecyl- and octadecylammonium chloride. The complexes were applied to paper at concentrations of 2–4%. After drying the papers, a sodium hydroxide solution was applied to convert the complexes to the insoluble amine form, rendering the paper hydrophobic. SEM showed that the complexes were uniformly deposited onto the paper with no visible particles. Increased resistance of papers to water penetration was indicated by an increase in the contact angles of water droplets from not measurable to as much as 113°, and by longer times for total absorption of the droplets. Treated papers also absorbed less water than untreated papers, with the C16 amylose-hexadecylammonium chloride complex providing the greatest water resistance (81.2% less water absorbed than untreated paper). Unlike other technologies widely used for rendering paper hydrophobic, the materials used for this novel method are water soluble, non-toxic, biobased, and biodegradable.

The rheological properties of aqueous solutions and films made from blends of polyvinyl alcohol (PVOH) and amylose-hexadecylammonium chloride inclusion complexes (Hex-Am) were investigated to better understand the polymer interactions and processing parameters. Aqueous solutions of Hex-Am displayed non-Newtonian shear thinning characteristics, becoming highly viscous at 4.2% solids and forming a strong mechanical gel at 10% solids. Cationic Hex-Am was observed to have dramatically different rheological temperature response profiles from anionic amylose-sodium palmitate inclusion complexes, displaying a precipitous increase in viscosity upon cooling from 95°C to 50°C. Aqueous solution blends of 1:1 PVOH/Hex-Am lack this precipitous increase in viscosity, indicating that PVOH reduces amylose-chain entanglement. Films cast from varying blends of Hex-Am and PVOH were thermostable to 200°C, and displayed decreasing storage modulus with increasing concentrations of PVOH in film blends. Films cast from Hex-Am/PVOH absorb water vapor at lower rates than their constitutive polymers.

Development of viscoelastic doughs from non‐wheat proteins allows for a wider range of gluten‐free products. Little work has been completed to describe mechanisms of zein functionality in food systems. To identify factors responsible for dough development in zein–starch mixtures and their influence on zein bread quality, a mixture of 20% zein–80% maize starch was mixed with water and various reagents. Salts, NaSCN, NaCl, and Na2SO4were evaluated at concentrations from 0 to 2M for their influence on the properties of zein–starch dough systems. NaSCN at low concentrations produced softer dough. Ethanol treatments produced softer more workable dough in the absence of salts. Increasing concentrations of NaCl and Na2SO4resulted in coalescing of the proteins and no dough formation. The addition of β‐ME had minimal softening effects on zein–starch dough. Specific volumes of zein–starch bread increased with decreasing NaCl addition in bread formulations. Likewise, including 5% ethanol (v/v) in the bread formula increased bread quality.

Water soluble amylose-hexadecyl ammonium chloride complexes were prepared from high amylose corn starch and hexadecyl ammonium chloride by excess steam jet cooking. Amylose inclusion complexes were spray dried to determine the viability of spray drying as a production method. The variables tested in the spray drying process were the% solids of the amylose-hexadecyl ammonium chloride complex being fed into the spray dryer, feed rate and the spray dryer outlet temperature. The amylose-inclusion complexes remained intact in all spray drying conditions tested as determined by X-ray diffraction. The rheological properties of solutions of the spray dried amylose-complexes remained unchanged when compared with the freeze dried control. Particle density and moisture content decreased with increased outlet temperature while particle size increased. X-ray diffraction and DSC analysis confirmed the formation of type II amylose inclusion complexes. Spray drying is a high throughput, low cost continuous commercial production method, which when coupled with excess steam jet cooking allows for the industrial scale production of cationic amylose-hexadecyl ammonium chloride complexes which may have value as flocculating and filtration enhancing agents and other aspects of paper production.

Although the insecticidal properties of some plant essential oils are well-documented, their use in integrated pest and vector management is complicated by their high volatility, low thermal stability, high sensitivity to oxidation, and low solubility in water. We investigated the use of bio-based N-1-hexadecylammonium chloride and sodium palmitate amylose inclusion complexes as emulsifiers for two essential oils, garlic and asafoetida, known to be highly toxic to mosquito larvae. Four emulsions of each essential oil based on amylose hexadecylammonium chloride and amylose sodium palmitate inclusion complexes were evaluated for their toxicity against Aedes aegypti L. larvae relative to bulk essential oils. All emulsions were significantly more toxic than the bulk essential oil with the lethal dosage ratios ranging from 1.09&ndash, 1.30 relative to bulk essential oil. Droplet numbers ranged from 1.11 &times, 109 to 9.55 &times, 109 per mL and did not change significantly after a 6-month storage period. These findings demonstrated that amylose inclusion complexes enhanced the toxicity of essential oils and could be used to develop new essential oil based larvicides for use in integrated vector management.

Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein.; Results: Dried alfalfa leaves contained 260 g kg-1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg-1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg-1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg-1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m2 g-1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0.; Conclusions: It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.

There continues to be interest in developing solvent-resistant articles from biobased renewable materials to successfully compete with petrochemical products. It was previously shown that reaction of zein with polyethylenemaleic anhydride (PEMA) provides articles that are solvent resistant. The gelation kinetics for the reaction of PEMA with zein was investigated rheologically to better understand this chemistry. The reaction of the nucleophilic groups on zein with the anhydrides on PEMA is the main cause for the gelation reaction. The gelation time was defined as being the point when the elastic modulus (G′) and viscous modulus (G″) cross. In this work, the rate of reaction, in terms of time to gelation, was studied in N,N-dimethylformamide solution for which the amount of PEMA, the reaction temperature, and the overall reaction concentration were varied. Exponential relationships were found between the gelation time and % PEMA, temperature, and % solids, as well as between elastic modulus with either % ...

Film-forming polymer technologies can contribute to insect-pest control by causing adverse effects directly to insects such as slowing development, causing mortality, and/or indirectly as a spray ingredient that improves pesticide efficacy by resisting environmental degradation such as wash-off by rain. Amylose complexes produced from either fatty acid [amylose sodium palmitate (Na-Palm)] or fatty ammonium salts [amylose-hexadecylammonium chloride complex (Hex-Am)], when blended with polyvinyl alcohol (PVOH), dry to form films that were significantly more water resistant then films formed by their constitutive components and adhered strongly to treated soybean [Glycine max (L.) Merrill] leaves with no impact on photosynthesis or yield in simulated field trials. As an experimental bioinsecticide formulation to resist wash-off, AfMNPV baculovirus was incorporated into both amylose complex formulations and sprayed on soybean. After a simulated rain event, soybean treated with the baculovirus/Na-Palm/PVOH (1:1) retained 93% of the original insecticidal activity against Trichoplusia ni (Hubner) larvae as compared with the baculovirus only treatment, 53% activity retained. Curiously, initial insecticidal efficacy of film-forming treatments was significantly lower against T. ni when compared with unformulated baculovirus treatments, thus prompting further investigations. Both amylose complexes reduced larval feeding when sprayed on soybean, corresponding with reduced insect mortality by the baculovirus, which must be ingested to initiate infection. Hex-Am film coating over artificial diet inhibited the growth and development of T. ni and caused increased T. ni mortality and developmental delay as film thickness of Hex-Am/PVOH increased. These investigations demonstrate the potential of a new modified starch complex formulation to serve as a protective film forming agent and contribute to control of insect pests.

Amylose-fatty (C12-C16) ammonium salt inclusion complexes are effective antimicrobial polymers causing growth inhibition of microbes at concentrations as low as 40 μg/mL of the complex (2 μg/mL active cationic ligand). The complex was more effective at controlling microbes than the uncomplexed ligand. The complexes were found to be particularly effective at inhibiting the growth of fungi, yeast, gram (+) bacteria, and algae; its performance was affected by pH. The complexes were not hemolytic at concentrations up to 2000 μg/mL. These agents were determined to be surface active polymers and their antimicrobial mode of action may involve cell membrane thinning or disruption, causing moderate leakage. Increased ligand concentration provided increased antimicrobial activity. Solutions of amylose complexes were found to be stable, retaining their antimicrobial efficacy after autoclaving, or after storage at room temperature for 6 months. Antimicrobial amylose complexes were produced using readily available inexpensive materials via an easily scalable process.

This study compared two methods for extracting the protein in pennycress (Thlaspi arvense L.) press cake and determined the composition and functional properties of the protein products. Proteins in pennycress press cake were extracted by using the conventional alkali-solubilization–acid-precipitation (AP) method or saline-based (SE) procedure (0.1 M NaCl at 50 °C). The extraction method has a major influence on the purity and functional properties of press cake protein products. AP had a lower protein yield (23 %) but much higher purity (90 % crude protein) compared with SE (45 % yield, 67 % crude protein). AP protein isolate had high foam capacity (120 ml), high foam stability (96 % foam volume retention) and high emulsion stability (24–35 min), and it was resistant to heat denaturation (3 % loss of solubility at pH 2 and pH 10). On the other hand, SE protein concentrate showed remarkably high solubility (>76 %) between pH 2 and 10 and exceptional emulsifying activity (226–412 m2/g protein), but was more susceptible to heat denaturation at pH 7 and pH 10 (65–78 % loss of solubility). These results strongly demonstrate that higher purity pennycress press cake protein can be produced by either saline extraction or acid precipitation and have functional properties that are desirable for non-food uses.

The use of starch in polymer composites for film production has been studied for increasing biodegradability, improving film properties and reducing cost. In this study, submicron particles were prepared from amylose-sodium palmitate complexes both by rapidly cooling jet-cooked starch-palmitic acid mixtures and by acidifying solutions of starch-sodium palmitate complexes. Films were cast containing poly(vinyl alcohol) (PVOH) with up to 50% starch particles. Tensile strength decreased and Young's modulus increased with starch concentration, but percent elongations remained similar to controls regardless of preparation method or starch content. Microscopy showed particulate starch distribution in films made with rapidly cooled starch-palmitic acid particles but smooth, diffuse starch staining with acidified sodium palmitate complexes. The mild effects on tensile properties suggest that submicron starch particles prepared from amylose-palmitic acid complexes provide a useful, commercially viable approach for PVOH film modification.

The impact on polymer properties [molecular weight, monomer conversion, graft content, graft efficiency and anhydroglucose units between grafts (AGU/graft)] that result from changing the solvent for the graft co-polymerization of acrylamide onto starch from water to dimethylsulfoxide (DMSO) was evaluated. Other reaction conditions were varied to determine their impact on properties, including solution solids (2.8–10.5 %), acrylamide (0.18–0.89 M), initiator (0.91–3.78 mM), and temperature (40–90 °C). Changing the solvent from water to DMSO had a large impact on the properties of the starch graft co-polymer at all reaction conditions. The most important difference was observed in the architecture of the resulting starch graft co-polymer. The number average molecular weight (Mn) of the polyacrylamide grafts as well as the number of AGU/graft was much lower when the reaction was performed in DMSO; the polymer was more comb-like. When conducted in water the Mn of the polyacrylamide grafts could be as high as 450,000 with over 6,500 AGU/graft. When DMSO was the solvent the Mn could be as low as 7,500 with 200 AGU/graft. The ability to control and generate starch graft co-polymers with dramatically different architecture may allow starch to be tuned to deliver improved properties for current or new applications.

A novel emulsifier, Frost grape polysaccharide (FGP), isolated from natural exudate of the species Vitis riparia Michx, was physically and rheologically characterized. The determination of the physical, structural, thermodynamic, emulsification, film, and rheological properties of FGP provide essential details for the commercial adoption of this novel plant polysaccharide. FGP is capable of producing exceptionally stable emulsions when compared with the industrially ubiquitous gum arabic (GA). The FGP isolate contained a negligible amount of nitrogen (0.03%), indicating that it does not contain an associated glycoprotein, unlike GA. Solutions of FGP have a high degree of thermostability, displaying no loss in viscosity with temperature cycling and no thermal degradation when held at 90 °C. FGP is an excellent film former, producing high tensile strength films which remain intact at temperatures up to 200 °C. This work identified a number of potential food and pharmaceutical applications where FGP is significantly superior to GA.

Polymer film blends of hydroxypropyl methylcellulose (HPMC) and amylose-sodium palmitate inclusion complexes (Na-Palm) were produced with no plasticizer, and were observed to have improved physical and gas barrier properties as compared with pure HPMC. The crystalline amylose helices incorporating the hydrophobic sodium palmitate ligand decreased the water vapor permeability of a 50/50% blended film of HPMC/Na-Palm by 40% and decreased oxygen permeability by 96%. The incorporation of 25% Na-Palm into HPMC films resulted in improved elongation, Young’s modulus and toughness. Addition of the amylose-complexes produced relatively smooth, high clarity films which had reduced solubility in neutral and acidic solutions. Increasing concentrations of Na-Palm increased film thermal resilience and increased storage modulus at high temperatures. The heat deflection temperature of the films also increased with increasing concentrations of amylose-complex; HPMC/Na-Palm film blends with >50% Na-Palm displayed almost no material deformation up to 250 °C.

In view of continuing interest in the utilization of agricultural by-products, we have converted cellulose, wheat straw, barley straw, and rice hull into carboxymethylcellulose (CMC), using both conventional heat and microwave-assisted synthesis. The application of microwave technology has enabled an improved synthesis of CMC to be conducted, with similar degrees of substitution as conventional heat (3 h) but reduced reactions times (30 min). The CMC obtained can be acetylated to form carboxymethylcellulose acetate (CMC acetate). The FT-IR and solid state 13 C NMR spectra of these materials have been characterized. With variations in the degrees of substitution of carboxymethyl and acetyl groups, a family of CMC acetate products can be made. The polymer may perhaps find applications as filtration membranes, functional fillers in polymers, and additives in commercial formulations.

Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130°C, with 20% starch content. An amylose-free cornstarch, waxy maize, was used for this research, and the heat treatment range was from ambient temperature to 170°C. The heat-treated starch (HTS) was characterized by optical microscopy, dynamic light scattering, and size exclusion chromatography. The composites were characterized by mechanical analysis (stress–strain) and by scanning electron microscopy. The mechanical tests of composites revealed a dramatic increase in the modulus and tensile strength when the gelatinized starch was incorporated. When the starch was not gelatinized, starch did not contribute to the increase in the modulus and tensile strength because of its small surface area, thus weak interaction with the matrix. The reinforcing effect of starch as filler was reduced as the heating temperature of starch was increased to higher than 120°C. The variation of reinforcement effect of HTS as filler was explained by the interaction between starch and matrix material, latex.

This study evaluated two methods, saline extraction (SE) and conventional acid precipitation (AP), to recover proteins from pennycress (Thlaspi arvense L.) seed meal. SE was done using 0.1 M NaCl at 50 °C while AP involved alkaline extraction (pH 10) first followed by protein precipitation at pH 4. Composition, amino acid profiles, and functional properties (solubility, foaming, emulsification, water-holding capacity, heat coagulability) of the resultant protein extracts were compared. SE and AP produced pennycress protein extracts that were sinigrin-free and containing at least 90% (db) crude protein, which classifies the extracts as protein isolates (PI). Extraction method had major influence on the amino acid profiles and functional properties of the protein isolates. Pennycress SEPI was markedly more soluble (68–91% solubility at pH 2 and ≥7) and had excellent emulsifying properties that were clearly superior to those of APPI. On the other hand, APPI had better foaming properties and was more stable to heating than SEPI. These results strongly demonstrate that high-purity pennycress seed protein isolates can be produced by either saline extraction or acid precipitation and have functional properties that are desirable for non-food uses.

Zein is a prolamine protein found in corn and has good potential in the development of industrial bioplastics. In this work, zein was modified with several isocyanates and diisocyanates in solution to evaluate its potential usage in bioplastics. The major reaction pathways were identified with the help of NMR and FTIR. For all the isocyanates employed, the surface free energy of the modified zein decreased, which phenomenon indicates decreased hydrophilicity. The moisture uptake decreased with isocyanate and diisocyanate modifications. Gel electrophoretic patterns showed that diisocyanate cross-linked a portion of zein to generate higher molecular weight species. DSC data showed single glass transition temperatures in all cases indicative that homogeneous blends were formed. The mechanical properties of modified zein were either similar to unmodified zein or reduced in some cases. Based on results from NMR and FTIR findings a reaction scheme is proposed. Our findings suggest that the reaction of zein with diisocyanates has potential usage in bioplastics formulations.

A new class of zein additives was investigated, thiocyanate salts. Ammonium, potassium, guanidine (GTC), and magnesium thiocyanate salts were added to solutions of zein in with various amounts of tri(ethylene glycol) (TEG), cast as films, and then tested to determine the impact that each salt had on properties. The presence of these salts affected solution rheology and intrinsic viscosity, demonstrating that the salts interacted with the protein. It was found that these salts acted as plasticizers, as they lowered the glass transition temperature of zein when evaluated with differential scanning calorimetry. In zein films in which TEG was present, these salts increased elongation and reduced tensile strength. However, unlike traditional plasticizers (such as TEG), when the salts were used as the only additive, elongation was not increased and tensile strength was not decreased. Of the salts tested, GTC in combination with TEG was found to increase elongation the most. The impact of salts on elong...

Current interest in pennycress ( Thlaspi arvense L.) comes from its seed oil, which is being evaluated for biofuel production. The seed also has notable protein content (27% moisture-free, oil-free basis). The effects of oil processing conditions on functionality of pennycress seed proteins were determined to identify potential uses for the meal. Whole seeds were either simply cold-pressed or heated at 82 °C with residence time of 50 min in the seed conditioner. Oil was extracted by screw-pressing. Composition and functional properties (solubility, foaming, emulsification, water-holding capacity) of extractable proteins in press cakes and unprocessed pennycress seed were determined and compared. Pennycress seed protein had predominantly albumins and globulins, no prolamins, and few glutelins. Cooking significantly reduced the amounts of albumins and globulins in the press cake. All samples showed the lowest solubility (10%) at pH 4 and only moderate solubility (35–45%) as pH increased. Both seed and press cake proteins had excellent foaming and emulsifying properties, but press cake proteins had higher water-holding capacities. These results showed that heat treatment during oil processing adversely affected the albumins and globulins, as well as solubility behavior of protein in pennycress seed and press cake, but the protein still has other useful functional properties.

In order to more fully utilize pennycress, a potentially viable bio-diesel source, the proteinaceous components were extracted from pennycress seeds and press cake. The amino acid composition of the proteins present in pennycress was typical for proteins derived from plants, with glycine, glutamic acid and alanine being prevalent. Water, 0.5 M sodium chloride, 60% acetic acid, 0.1 M sodium hydroxide and ethanol were used in sequential order to remove the protein from pennycress seeds and press cake and determine the various soluble protein fractions. Extraction temperature was varied from 5 to 77 °C. The highest yield of material (35%) was obtained by extracting pennycress seeds with water at 77 °C. However, this material had only moderate levels of protein (25%) with the remainder being carbohydrates and oil (as determined by infrared spectroscopy). The use of 0.5 M sodium chloride to remove protein from press cake at 5 °C produced material with the highest protein content (83%), but extraction yield was 25%. When extractions were carried out at 77 °C, oil typically began to be a major impurity in the protein. Using bomb calorimetry, the material remaining after extraction was found to have some value as a fuel source.

Paulownia wood flour (PWF), a byproduct of milling lumber, was tested as bio-filler with polylactic acid (PLA). Paulownia wood (PW) shavings were milled and separated into particle fractions and then blended with PLA with a single screw extruder. Mechanical and thermal properties were tested. Differential scanning calorimetry showed that PLA–PW blends containing smaller particle sizes had lower glass transition and melting temperatures compared to blends containing larger particle sizes. Biocomposites composed of smaller particles exhibited tensile strength values similar to neat PLA but had Young's modulus values that were 25% higher than neat PLA. However, elongation values decreased in all PLA–PW blends compared to neat PLA. Microscopic examination of the biocomposites revealed distinct differences in their morphologies. PLA–PWF blends exhibited color changes based on the size of the wood particles employed.

Amylose inclusion complexes prepared from cationic fatty ammonium salts and jet-cooked high amylose starch were combined with poly(vinyl alcohol) (PVOH) to form glycerol-plasticized films. For the octadecylammonium salt complexes, elongation was significantly higher than the PVOH control when the amount of complex incorporated was from 20% to 70%. For the dodecyl- and hexadecylammonium salt complexes, elongation was significantly higher than PVOH films for 20% to 40% incorporation of cationic complex. Tensile strength declined with increasing levels of amylose-ammonium salt complex, and surface hydrophobicity (contact angle) was significantly higher than PVOH films. Microscopy showed no phase separation or phase inversion, suggesting intimate mixing due to ionic interactions between cationic ammonium salt complexes and the hydroxyl groups of PVOH. The high elongations of these films and increased water contact angles are marketable advantages, along with the lower cost and increased biodegradability of the starch-based component. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44110.

Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein.Dried alfalfa leaves contained 260 g kgIt is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry.

Corn protein (zein) was melt-processed with methylenediphenyl 4,4′-diisocyanate (MDI) using triethylamine (TEA) as a catalyst to facilitate the reaction of the isocyanate groups with the nucleophilic moieties present on zein. The product of the reaction was examined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to monitor changes in molecular weight. Techniques used to evaluate property changes after reaction included FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and evaluation of mechanical properties. Our findings demonstrated that zein reacts with MDI in the melt state generating higher molecular weight compounds that after compression molding have improved physical properties and solvent resistance.

Blends of zein and nylon-6 (55 k) in formic acid were used to produce solution cast films and electrospun fibers. When the amount of nylon-6 was 8 % or less blends were formed that had improved tensile strength and reduced solubility. The blends were analyzed using physical property measurements, DSC and IR spectra. Using between 2 and 8 % nylon-6 provided a 33 % increase in tensile strength. Young’s modulus increased by over 50 % in this range. In general elongation was lower for all formulations. Surprisingly the cast films having 0.5–8 % nylon-6 had improved solvent resistance to 90 % ethanol/water. Electrospun fibers were produced from formic acid solutions of zein and nylon-6 where the amount of nylon was 0, 2 and 6. Fibers produced from 27 % spinning solids had average diameters on the order of 0.5 μm. Reducing the spinning solids to 21 % provide slightly smaller fibers however, the fibers had more defects.

Polymeric composites based on cotton burr and cottonseed bull have been prepared by melt blending and extrusion. For poly(lactic acid) (PLA) and low-density polyethylene (LDPE), addition of the fillers slightly changed the composite's thermal properties but significantly decreased the composite's mechanical properties. Heat treatment prior to extrusion resulted in composites with better tensile strength and Young's modulus. The use of maleic anhydride and peroxide only slightly improved the physical properties of the LDPE materials, but the effect was less clear for the PLA materials. The PLA-filler composites may be useful for lowering the cost of the materials in applications that can tolerate the decreased properties. In addition, the addition of fillers to LDPE might be beneficial in applications to improve stiffness or to improve biodegradability.