Cellulose, the most abundant biopolymer on Earth, is biodegradable, nontoxic, and derived from renewable sources. Its properties and applications depend on the extraction methods and sources, making plant waste reuse a sustainable production option. This study aimed to assess the potential of cowpea pod skin (Vigna unguiculata) as a source of microcellulose (CPMC) using a chemical-mechanical process involving ball milling combined with acid hydrolysis. For a comparative analysis of the method's efficiency and biomass performance, corn straw (Zea mays L., CSMC) and pineapple peel (Ananas comosus, PPMC) were also utilized as extraction sources. The chemical composition of microcelluloses (MCs) was investigated by Fourier Transform Infrared Spectroscopy (FTIR), thermal behavior by Thermogravimetric Analysis (TGA), crystallinity by X-ray Diffraction (XRD), morphologies by Scanning Electron Microscopy (SEM), and shape and size by Atomic Force Microscopy (AFM). In the FTIR spectra, absorption bands characteristic of cellulose were observed at 3408 cm^-1 (hydroxyl group OH stretching), 1640 cm^-1 (adsorbed water molecules), 1205 cm^-1 (O-H deformation vibration), 1165 cm^-1 (C-O-C- stretching vibration), 1113 cm^-1 (glucose ring stretching vibration), 1055 cm^-1 (CO stretching), 1028 cm^-1 (C-OH stretching), and 895 cm^-1 (β-glycosidic bonds). The TGA/DTG curves of all the samples showed three stages of mass loss, and CPMC proved to be the sample with the greatest thermal stability. The crystallinity indices of the MCs samples ranged between 69.23-75%. The micrographs show compact and lamellar materials. However, AFM measurements revealed distinct nanostructures for each of the MCs obtained, displaying lamellar structures from 20 to 280 nm. Therefore, this method was efficient for extracting MCs from different types of biomass. The analyses demonstrated greater efficiency in the CPMC and CSMC samples. In this context, they have become promising candidates for application in a wide range of industrial materials.

This research focused on the development and characterization of gelatin-based films incorporated with cellulose microfibrils (CMFs) extracted from cowpea pod skin (Vigna unguiculata, CPMC) and corn straw (Zea mays, CSMC). The use of CPMC to produce gelatin films has not been previously reported in the literature. Eleven formulations were prepared based on a 2² factorial design with four axial and three central points, in addition to a control film (FC) composed of 1.00% gelatin and 1.00% glycerol without CMFs. The physical, chemical, structural, and mechanical properties of the films were evaluated. The optimized formulation (FO), containing 1.00% CPMC and 1.00% CSMC, exhibited a four-fold increase in tensile strength (2.71 MPa) compared to the control. Water vapor permeability was significantly reduced (from 6.33 × 10⁻⁴ to 2.82 × 10⁻⁴ gH₂O·mm/m²·h·mmHg), and solubility decreased to 75.82%. Biodegradability was modulated, with FO exhibiting 73.06% degradation over three days versus complete degradation of FC within one day. The incorporation of CMFs, particularly from agro-industrial residues, significantly improved the structural integrity and barrier properties of the films, highlighting their potential for use in biodegradable packaging systems.

In this study, bean starch films were developed and treated with dielectric barrier discharge (DBD) cold plasma (5 min (DBD5), 10 min (DBD10), and 15 min (DBD15)) and pulsed light (PL) radiation (4 J cm⁻² (PL4), 8 J cm⁻² (PL8), and 12 J cm⁻² (PL12)), and the effects of these treatments on the physical, barrier, mechanical, morphological, and structural properties were evaluated, as well as the practical application of the films in bread storage for 7 days. Both treatments significantly modified the film properties (p < 0.05). Film thickness decreased from 95 µm (control) to 87 µm (PL12), while solubility was reduced from 39.40% (control) to 25.32% (PL12), indicating improved water resistance. Reductions in water vapor permeability (WVP) were also observed, with a more pronounced effect for PL12 (approximately 55% reduction compared to the control). The contact angle increased from 58.30° (control) to 67.76° (PL12), indicating a moderate increase in surface hydrophobicity. The DBD cold plasma treatment increased tensile strength (up to 16.05 MPa in DBD15) and reduced elongation (44.72%), whereas PL, especially at PL8, increased flexibility (60.36%). Morphological analyses indicated increased surface roughness for DBD-treated films, while structural analyses suggested subtle changes in molecular organization rather than the formation of well-defined crystalline domains. During bread storage, the treated films, particularly PL12, were significantly more effective than the control in delaying bread staling (final firmness of 6.67 N vs. 11.82 N), reducing mass loss (5.66% vs. 12.66%), and maintaining higher water activity, thereby better preserving product quality. Overall, both treatments showed potential for tailoring film properties: DBD was more effective in enhancing mechanical strength, while PL promoted improvements in barrier properties and practical performance. Therefore, physical treatments, particularly PL, represent promising strategies to overcome intrinsic limitations of starch-based films and to develop packaging materials with potential applications in bakery product preservation.

Resin Transfer Molding (RTM) is a broadly applied composite fabrication technique in which liquid resin is injected into a sealed mold housing a fibrous preform. This technique enables the industrial-scale production of large, complex-shaped components while ensuring high quality and excellent material properties. A notable phenomenon in the Resin Transfer Molding process, particularly when vegetable fibers are used as reinforcement, involves resin absorption by the fibers during the filling process, which causes a deceleration of the fluid flow front, leading to an increase in mold filling time. This phenomenon has been scarcely investigated in the scientific literature, particularly under non-isothermal situations. In this context, this paper focuses on the resin injection in a closed and heated mold, emphasizing the evaluation of the capillary number of the fluid flow. The model incorporates a transient, radial, and 3D flow, variable resin viscosity, and includes the effect of resin absorption by the fibers. Simulations were carried out using CFD techniques, evaluating the effect of fixed injection gauge pressure (2.0 bar) or volumetric flow rate (3.5 × 10⁻⁸ m³/s) on the infiltration transient behavior. The numerical results of the capillary number of the flow, resin viscosity, and resin superficial velocity as a function of radial position were analyzed. Based on the analysis of the capillary number field, with the sole objective of minimizing the potential formation of voids in the manufactured composite, optimal operating parameters were identified, namely, a mold heating temperature of 30 °C and an optimal resin injection condition consisting of a constant volumetric flow rate of 3.5 × 10⁻⁸ m³/s. Further, the volumetric fraction, pressure, and temperature fields are presented and examined. The numerical modeling used builds upon a previously validated numerical framework and extends its application by evaluating the potential generation of voids through the analysis of the capillary number field.