Cassava-Starch-Based Films Incorporated with Buriti (Mauritia flexuosa L.) Oil: A New Active and Bioactive Material for Food Packaging Applications

The objective of this study was to develop and characterize cassava-starch-based films incorporated with buriti (Mauritia flexuosa L.) oil and emulsifier (Tween 20). An experimental factorial design 22 with three central points was used to develop the films, by varying the concentrations of buriti oil (0.15 to 0.45% w/v) and emulsifier (0.02 to 0.04% w/v). Film thickness and weight increased with increasing buriti oil concentration. The water vapor permeability of the films ranged from 0.22 to 0.366 g mm h−1 m−2 kPa−1. The tensile strength values varied from 4.21 to 6.95 MPa, the elasticity modulus varied from 538.53 to 722.78 MPa, and elongation to rupture varied from 1.13 to 1.66%. The film color was characterized as yellowish, dark, and intense (higher oil content); and clear and a low-intensity color (lower oil content). The films presented a total carotenoid content ranging from 3.63 to 29.73 μg β-carotene/g, which may have resulted in their antioxidant potential against DPPH• (1,1-diphenyl-2-picryl-hydrazyl) radical (from 74.28 to 87.74%). The central formulation of the experimental design (buriti oil 0.30% and emulsifier 0.03%) presented a good performance and can be applied as packaging for foods with a lower water content and that demand protection against oxidation.

Hybrid films from plant and bacterial nanocellulose: mechanical and barrier properties

The accumulation of petroleum polymers compromises biodiversity and causes environmental problems. Nanocellulose enhances biodegradability and can improve the physical-mechanical performance of materials. The objective was to produce and characterize hybrid films composed of bacterial cellulose (BC) and plant nanocellulose from Eucalyptus (Euc) or Pinus (Pin). Films were produced by the casting method using filmogenic suspensions with different cellulose nanofibrils (CNFs) proportions from both the sources (0, 25, 50, 75 and 100 %). CNFs suspensions were characterized by transmission electron microscopy. The morphology of the films was analyzed using scanning electron microscopy. In addition, the transparency, contact angle, wettability, oil and water vapor barrier and mechanical properties were also evaluated. The contact angles were smaller for films with BC and the wettability was greater when comparing BC with plant CNFs (0.10 ° s − 1 {\text{s}^{-1}} for 75 % Euc/25 % BC and 0.20 ° s − 1 {\text{s}^{-1}} for 25 % Euc/75 % BC). The water vapor permeability (WVP) of the 100 % BC films and the 25 % Euc/75 % BC composition were the highest among the studied compositions. Tensile strength, Young’s modulus and puncture strength decreased considerably with the addition of BC in the films. More studies regarding pre-treatments to purify BC are needed to improve the mechanical properties of the films.

Comparison of Numerical HMT Codes to Simulate MBV Test of Hemp-Earth Composites

Bio-based and earth materials are growingly used for the building envelopes because of their numerous benefits such as slight environmental impact, great hygrothermal performances, effective regulation of the perceived indoor air quality and human comfort. In such materials, the phenomenon of mass transfer is complex and has a great impact on the performance of building envelope. Therefore, it is important to identify and understand the hygrothermal phenomena to be able to simulate accurately the envelope behavior. Nevertheless, the classical models that depict hygric transport within building materials seem not accurate enough for bio-based materials as they are simplified on several points of view. The correlation that exists between water content and relative humidity is mostly simplified and is modeled by a single curve, the hygric storage capacity is often overstated and the hysteresis is neglected. This paper deals with numerical study of hygric transfer within hemp-earth building material by using WUFI® Pro 6.5, a commercial software, and TMC code developed at the LGCGM (Moissette and Bart, 2009) . This code was validated regarding EN 15026 standard (Moissette and Bart, 2009) and has evolved over the years by integrating the hysteresis phenomena (Aït-Oumeziane et al., 2015). Thus, a significant enhancement of the numerical simulations on desorption phase was shown. This study investigates the simulation of MBV test performed on a hemp-earth material for which only the adsorption curve is known as input. Missing parameters (water vapor permeability and desorption curve) are fitted considering the first cycle of MBV test with TMC code. Then, MBV test is simulated with WUFI® Pro 6.5 and TMC code without and with hysteresis. The results highlight the need to include hysteresis to accurately simulate dynamic hygric phenomena, and show that it is possible to find missing parameters by fitting dynamic solicitations.

Evaluation of a Marine Dredged Sediment as Raw Material Compared to Volcanic Scoria for the Development of Lime-Pozzolan Eco-Binders

In the context of global warming, the built environment offers relevant opportunities to reduce GHG emissions that underlie climate change. In particular, this can be achieved with the development of low-embodied energy building materials such as bio-based concretes. Hemp concrete has been the subject of many investigations in the field of non-load bearing infill walls in France since the early 1990s. In addition to hygrothermal performances, the use of crop by-products definitely helps to limit the carbon footprint. Hemp concretes are often produced by mixing the plant aggregates with lime-based binders. The latter have many benefits among which the water vapor permeability. However, CO2 emissions due to the decarbonation of limestone for the production of lime largely contribute to the overall environmental balance of these materials. The use of natural pozzolans (volcanic scoria) combined with hydrated lime goes back to the Greco-Roman period and reduces carbon emissions. Nonetheless, it does not necessarily meet the issue related to the depletion of granular natural resources. Hence, this study deals with the design of a new low-carbon binder based on marine dredged sediment seen as an alternative strategic granular resource that can be considered renewable. The sediment comes from the Port of Dunkirk in the North of France and is mainly composed of silt and quartz sand. It was finely ground and compared to a lowly reactive basaltic pozzolan. Lime-pozzolan pastes were prepared and stored in a moist environment under room (20°C) and high temperature (50°C). The hardening kinetics of pastes was followed through mineralogical studies (TGA, XRD) and compressive strength development. The results showed that the hardening of pastes including the marine sediment was suitable in the case of samples stored at 50°C and make it possible to use such a binder for precast bio-based concretes.

Reuse of Textile Waste to Production of the Fibrous Antibacterial Membrane with Filtration Potential

Wasted synthetic fabrics are a type of textile waste source; the reuse of them brings environmental protection and turns waste into a valuable material. In this work, the used nylon (polyamide) stockings were transmuted into a fine fibrous membrane via an electrospinning process. In addition, the safety antibacterial agent, monoacylglycerol (MAG), was incorporated into a recycled fibrous membrane. The results revealed that the neat, recycled polyamide (rPA) fibers with a hydrophobic surface could be converted into hydrophilic fibers by blending various amounts of MAG with rPA solution prior to electrospinning. The filtration efficiency and air/water vapor permeability of the two types of produced membranes, neat rPA, and rPA/MAG, were tested. Their filtration efficiency (E100) was more than 92% and 96%, respectively. The membranes were classified according to Standard EN1822, and therefore, the membranes rPA and rPA/MAG were assigned to the classes E10 and E11, respectively. The air permeability was not affected by the addition of MAG, and water vapor permeability was slightly enhanced. Based on the obtained data, prepared rPA/MAG fibrous membranes can be evaluated as antifouling against both tested bacterial strains and antimicrobial against S. aureus.

Water Repellency/Proof/Vapor Permeability Characteristics of Coated and Laminated Breathable Fabrics for Outdoor Clothing

This study examined the water repellency (WR), waterproof, and water vapor permeability (WVP) characteristics of twelve types of laminated and coated woven fabrics for outdoor clothing. These characteristics were compared with the fabric structural parameters, such as cover factor, thickness, and weight, and surface modification (finishing) factors, such as coating, laminating, and Teflon treatments. In addition, an eco-friendly process for surface modification was proposed followed by a summary. Superior waterproof-breathable characteristics with 100% water-repellency were achieved in specimen 3 in group A by treatment with a hydrophilic laminated finish using nylon woven fabric with a cover factor between 0.7 and 0.9 in a 2.5-layered fabric, which was the best specimen with waterproof-breathable characteristics. A high WVP in the coated and laminated fabrics was observed in the fabrics with a low weave density coefficient (WDC) and low thickness per unit weight of the fabric, whereas superior water repellency and waterproof characteristics were observed in the high-cover-factor (WDC) fabric with appropriate fabric thickness. The determination coefficient (R2) from regression analysis between the WVP and fabric structural parameters indicated a higher contribution of the fabric structural parameters than surface modification factors, such as coating and laminating to the WVP in the coated and laminated fabrics. Furthermore, the cover factor was the most important factor influencing the WVP of the waterproof-breathable fabrics. Of twelve coated and laminated fabrics, the laminated nylon and nylon/cotton composite fabrics showed superior WVP with high WR and waterproof characteristics. Accordingly, based on the WR, waterproof, and WVP characteristics of the coated and laminated breathable fabrics, the laminating method, as an eco-friendly process, is recommended to obtain better waterproof-breathable fabrics.

Physical Properties of Starch/Powdered Activated Carbon Composite Films

In the present study, starch/powdered activated carbon composite films were prepared by incorporating various amounts of powdered activated carbon (PAC)—1–5, 10, and 15 %—into a starch matrix, using the solvent casting method. The effect of PAC addition on the biopolymer film was investigated. The mechanical properties were examined by ultra-nanoindentation, nanoscratch, and micro-tensile tests. Since the mechanical properties of biopolymer films are correlated with their structure, the effect of PAC addition was tested using X-ray diffraction. The surface parameters morphology and wettability were analyzed by atomic force microscopy (AFM) and contact angle measurements. The barrier properties were examined by determining water vapor permeability and the water solubility index. The obtained results did not show a monotonic dependence of the mechanical parameters on PAC content, with the exception of the maximum strain, which decreased as the amount of the additive increased. The visible effect of PAC addition was manifested in changes in the adhesive force value and in water vapor permeability (WVP). The barrier properties decreased with the increase of the filler content.

Sunflower (Helianthus annuus L.) Seed Hull Waste: Composition, Antioxidant Activity, and Filler Performance in Pectin-Based Film Composites

Helianthus annuus L. seed hull is an abundant waste of the edible oil industry. To envisage potential applications of this waste, here, we aimed to analyze the chemical composition of milled sunflower hulls (SP), constituted mainly by 210 μm (51.4%) and 420 μm (27.6%) average mesh particle sizes. SP contained almost 30% of cellulose, 26.4% of lignin, 38.5% of neutral sugars, mainly hemicelluloses, and only 1.3% of proteins. The important lignin content and low pectin content (4.0% of uronic acids) present in SP were both ascribed to its low hydrophilic behavior and hydration capacity. Phenolic compounds were mostly proanthocyanidins (168 mg/100 g SP), with lower amounts of extractable (31.4 mg/100 g SP) phenolics (O-caffeoylquinic acid), all of them associated with the DPPH radical scavenging capacity (95 mg ascorbic acid equiv./100 g) and ferric reducing power (FRAP: 152 mg ascorbic acid equiv./100 g) shown by SP. Esterified ferulic acid (52.9 mg/100 g SP) was also found, mostly as monomers and trimers. SP of 53 μm particle size was then assayed as a filler (0, 5, 8, and 12% concentrations) in calcium low methoxyl pectin-based films, which showed antioxidant capacity (DPPH and FRAP assays) in an SP-concentration-dependent manner. SP showed homogeneous dispersion in composite films equilibrated at 57.7% relative humidity. Water content decreased while film thickness increased with SP concentration. When loaded at a 12% level, the presence of 53-μm SP decreased the water vapor permeability and increased the normal stress at film fracture. Sunflower hulls can then be applied to the development of active materials like 12% SP film, which can be proposed as a food slice antioxidant separator to be investigated in a future work.

Developing Edible Starch Film Used for Packaging Seasonings in Instant Noodles

Edible starch-based film was developed for packaging seasoning applied in instant noodles. The edible film can quickly dissolve into hot water so that the seasoning bag can mix in the soup of instant noodles during preparation. To meet the specific requirements of the packaging, such as reasonable high tensile properties, ductility under arid conditions, and low gas permeability, hydroxypropyl cornstarch with various edible additives from food-grade ingredients were applied to enhance the functionality of starch film. In this work, xylose was used as a plasticizer, cellulose crystals were used as a reinforcing agent, and laver was used to decrease gas permeability. The microstructures, interface, and compatibility of various components and film performance were investigated using an optical microscope under polarized light, scanning electron microscope, gas permeability, and tensile testing. The relationship was established between processing methodologies, microstructures, and performances. The results showed that the developed starch-based film have a modulus of 960 MPa, tensile strength of 36 Mpa with 14% elongation, and water vapor permeability less than 5.8 g/m2.h under 20% RH condition at room temperature (25 °C), which meets the general requirements of the flavor bag packaging used in instant noodles.