RESUMO
Upgrading biogas to biomethane is of great interest to change the energy matrix by feeding the renewable fuel produced from biomass waste into natural gas grids or directly using it to replace fossil fuels. The study aimed to assess the adsorption equilibrium of CH4, CO2, and H2O on a coconut-shell activated carbon (CAC 8X30) to provide data for further studies on its efficiency in upgrading biogas by Pressure Swing Adsorption (PSA). The adsorbent was characterized, and equilibrium parameters were estimated from monocomponent CH4, CO2, and H2O equilibrium isotherms. Binary and ternary equilibrium isotherms were simulated, and the selectivity and adsorption capacity of the CAC 8X30 were calculated in dry and wet conditions and then compared with zeolite 13X as a reference material. Regarding characterization, Nitrogen and Hydrogen Physisorption results indicated that 94 % of the pore volume is concentrated in the region of micropores. The adsorption affinity with CAC 8X30 estimated from monocomponent isotherms was in the order KH20>KCO2>KCH4. IAST-Langmuir model simulations presented good agreement with experimental binary equilibrium data. Further simulations indicated equilibrium selectivity for CO2 over CH4 (e.g., 4.7 at 1 bar and 298 K for a mixture of CH4/CO2, 60/40 vol%), which increased in the presence of moisture, indicating its suitability for upgrading humid biogas. Simulations for zeolite 13X suggested that the material is unsuitable in the presence of water vapor but presents higher selectivity than the CAC 8X30 in dry conditions. Hence, the integration of both materials might be helpful for biogas upgrading.
RESUMO
Roller-compacted concrete (RCC) for pavements has experienced problems with its physical-mechanical performance over extended periods due to ambient and in situ curing conditions. Accordingly, this study aimed to present multiple regression equations for calculating the physical-mechanical properties of RCC for pavements under different service and mix conditions. For this purpose, the research included two cement and two water contents, one reduced with admixture, and four combinations of temperature and relative humidity. For model calibration and definition of the equations, cubic and beam samples were fabricated to carry out physical-mechanical tests, such as moisture content, shrinkage, and modulus of rupture. Laboratory-obtained data were studied with the Response Surface Methodology (RSM) to determine the best regression equations. The main findings determined that the behavior of a mixture of RCC at a prolonged ambient exposure time is possible because the surface models and the RSM were consistent with the different service and mix conditions. The models showed an accuracy of 98.99% in detecting shrinkage changes from 12 to 16% cement with 5.65% water in dry to wet ambient conditions. Similarly, moisture content and modulus of rupture had a 98.27 to 98.88% fit. Finally, the drying shrinkage, with mixes of 12% cement and water content variations with water-reducing admixture and superplasticizer effects, had an adjustment of 94.87%.
RESUMO
Several polyurethane-formulated films with curcumin and/or chitosan additives for food packaging have been previously obtained. The study examines the effect of the additives on the film's morphological, mechanical, barrier, and migration properties. Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), water contact angle, thermogravimetric and differential thermal analysis (TGA and DTGA), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), oxygen transmission rate (OTR), water vapor transmission rate (WVTR), and the overall and specific migration tests were conducted. The results show that the presence of chitosan significantly increased the overall migration and mechanical properties, such as the elongation at break, tensile strength, and Young's modulus of most polyurethane formulations, while curcumin had a minor influence on the mechanical performance. Based on the results, formulations with curcumin but without chitosan are suitable for food packaging.
RESUMO
Packaging materials based on biodegradable polymers are a viable alternative to replace conventional plastic packaging from fossil origin. The type of plasticizer used in these materials affects their functionality and performance. The effect of different plasticizers such as glycerol (GLY), sorbitol (SOR), and poly(ethylene glycol) (PEG) in concentrations of 5%, 10%, and 15% (w/w) on the structural features and functional properties of starch/PVOH/chitosan films was evaluated. The incorporation of a plasticizer increased the thickness of the biodegradable composite films. Furthermore, the material plasticized with 30% (w/w) sorbitol had the highest elongation at break, lowest water vapor permeability, and better thermal resistance. The results obtained in this study suggest that maize starch/PVOH/chitosan biodegradable composite films are a promising packaging material, and that sorbitol is the most suitable plasticizer for this formulation.
RESUMO
Starch is a biopolymer with enormous potential for generating new biodegradable packages due to its easy availability and low cost. However, due to its weak functional properties, limitation of its interaction with some hydroxyl groups and evaluation of blends with other polymers are necessary in order to improve its performance. Glycerol-plasticized acetylated corn starch films were developed using the casting method, and the impact of incorporating chitosan (TPS:CH) in various proportions (75:25, 50:50, and 25:75 v/v) was studied in the present research. The effect of chitosan ratios on the physical, mechanical, water-vapor barrier, and thermal properties of the film was studied. Chitosan-protonated amino groups promoted the formation of intermolecular bonds, improving tensile strength, thermal stability, hydrophobicity, water adsorption capacity, and the gas barrier of starch films. The results show that the film composed of TPS25-CH75 proved to be the best barrier to water vapor; thus, these composite films are excellent choices for developing biodegradable packaging for the food industry.
RESUMO
A novel nanocomposite whey protein-based film with nanoemulsified cocoa liquor (CL) was prepared using one-stage microfluidization to evaluate the emulsion properties and the effect of CL on the film properties by response surface methodology (RSM). The results indicated that the number of cycles by microfluidization had a significant effect (p < 0.05) on the particle size and polydispersity of the nanoemulsion, with a polyphenol retention of approximately 83%. CL decreased the solubility (<21.87%) and water vapor permeability (WVP) (<1.57 g mm h-1 m-2 kPa-1) of the film. FTIR analysis indicated that CL modified the secondary protein structure of the whey protein and decreased the mechanical properties of the film. These results demonstrate that applying the film as a coating is feasible and effective to improve the shelf life of bakery products with a high moisture content. This nanocomposite film is easy to produce and has potential applications in the food industry.
RESUMO
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.
RESUMO
The strategy of adding hydrophobic compounds to bio-based films (usually based on hydrophilic matrices), forming films containing emulsions, is a technique that has been used to improve some physical properties (such as reducing water solubility and water vapor permeability) and / or to impart properties, such as antioxidant and antimicrobial effects by carrying hydrophobic active components that would otherwise be insoluble in hydrophilic matrices. Although Pickering emulsions have been reported as presenting greater stability when compared with surfactant-stabilized emulsions, little is known about the drying stability of Pickering emulsions (which is important for film applications). Anyway, several studies have indicated that Pickering emulsions are interesting systems to improve the water vapor barrier properties of bio-based films and coatings, and to act as carriers of active hydrophobic components. On the other hand, the tensile properties of those films are usually impaired by the presence of Pickering emulsions. The objective of this review is to present recent developments and future perspectives in bio-based films loaded with Pickering emulsions. © 2020 Society of Chemical Industry.
Assuntos
Emulsões/química , Embalagem de Alimentos/instrumentação , Embalagem de Alimentos/tendências , Tecnologia de Alimentos , Interações Hidrofóbicas e Hidrofílicas , Vapor/análiseRESUMO
Starch is an excellent alternative to produce packaging materials, however, due to its high hydrophilicity, it is necessary to mix it with other polymers. Chitosan (CTS) is a polymer extracted from shrimp shells and crabs, which can be used to make biodegradable materials. The principal component of biodegradable was corn starch and chitosan, the copolymer pluronic F127 was incorporated in several concentrations and its effect on the water vapor barrier, morphological, thermal, and mechanical properties of the films was evaluated, because its incorporation in the formulation of biodegradable materials could increase its hydrophobicity. The surface of starch-chitosan composite films obtained was more homogeneous and smoother with the increase in the content of pluronic F127. The %S and WVP of the starch-chitosan films decreased from 42 to 3%, and 21 × 10-11 to 3 × 10-14 g. m-1s-1 Pa-1, respectively, with the incorporation of pluronic from 3%, which makes these materials a good alternative for product packaging.
Assuntos
Plásticos Biodegradáveis/química , Quitosana/química , Embalagem de Alimentos , Poloxâmero/química , Amido/química , Interações Hidrofóbicas e Hidrofílicas , Permeabilidade , Solubilidade , Vapor , Resistência à Tração , Água/químicaRESUMO
Compression molded biodegradable films based on poly(butylene succinate) (PBS) and poly(butylene adipate-co-terephthalate) (PBAT) at varying weights were prepared, and their relevant properties for packaging applications are here reported. The melt rheology of the blends was first studied, and the binary PBS/PBAT blends exhibited marked shear thinning and complex thermoreological behavior, due to the formation of a co-continuous morphology in the 50 wt% blend. The films were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical tensile tests, scanning electron microscopy (SEM), and oxygen and water vapor permeability. PBS crystallization was inhibited in the blends with higher contents of PBAT, and FTIR and SEM analysis suggested that limited interactions occur between the two polymer phases. The films showed increasing stiffness as the PBS percentage increased; further, a sharp decrease in elongation at break was noticed for the films containing percentages of PBS greater than 25 wt%. Gas permeability decreased with increasing PBS content, indicating that the barrier properties of PBS can be tuned by blending with PBAT. The results obtained point out that the blend containing 25 wt% PBS is a good compromise between elastic modulus (135 MPa) and deformation at break (390%) values. Overall, PBS/PBAT blends represent an alternative for packaging films, as they combine biodegradability, good barrier properties and reasonable mechanical behavior.
RESUMO
Baked foams made with plantain flour (PF) and sugarcane fiber (SF) were characterized by calorimetric, mechanical, physicochemical and structural techniques in order to assess the results induced by different sugarcane concentrations and fiber size on the structure of baked foams. The addition of SF to the baked samples increased their hydrophobic properties. Thermal conductivity (TC) decreased when the concentration of SF was 10 g and 7.5 g in the baked foams. The density of the biodegradable baked foams (BBFs) decreased with decreasing concentrations of SF, observing an inverse behavior in water vapor permeability (WVP) and solubility properties. The mechanical properties of the baked foams were more influenced by the concentration of SF than by the size of SF, obtained from different sieves. The scanning electron microscopy cross-sectional images of the BBFs showed that the size of SF affected the size and number of the internal cells in the BBFs.
RESUMO
Films of gellan gum:pectin blends were prepared by solvent casting method. Gellan gum:pectin mass ratios were varied (4:1; 1:1; 1:4) at different concentrations (3% or 4%) and glycerol was used as plasticizer (1 or 2%). The films were thin (18-30 µm), translucent, flexible, and homogeneous. The surface pH was suitable for buccal application. All films reached high mechanical resistance and the mucoadhesive ability of them was evidenced. High ratio of gellan gum improved the mechanical resistance and the mucoadhesion of the films as well as the control of drug release rates. The films did not disintegrate in simulate saliva up to 24 h and curcumin release could be sustained up to 12 h. The set of data evidence that the films designed in this work represent a potential platform for buccal drug delivery.
Assuntos
Pectinas/química , Polissacarídeos Bacterianos/química , Administração Bucal , Curcumina/administração & dosagem , Curcumina/química , Preparações de Ação Retardada/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Boca/efeitos dos fármacos , Mucosa Bucal/efeitos dos fármacos , Plastificantes/químicaRESUMO
This research work evaluated the influence of the type of incorporation and variation in the concentration of blackberry pulp (BL) and microencapsulated blackberry pulp (ML) powders by freeze-drying on the chemical and physical properties of arrowroot starch films. Blackberry powders were added to the film-forming suspension in different concentrations, 0%, 20%, 30% and 40% (mass/mass of dry starch) and through two different techniques, directly (D) and by sprinkling (S). Scanning electron microscopy (SEM) images revealed that the incorporation of blackberry powder has rendered the surface of the film rough and irregular. Films incorporated with BL and ML powders showed an increase in thickness and water solubility and a decrease in tensile strength in comparison with the film containing 0% powder. The incorporation of blackberry BL and ML powders into films transferred colour, anthocyanins and antioxidant capacity to the resulting films. Films added with blackberry powder by sprinkling were more soluble in water and presented higher antioxidant capacity than films incorporated directly, suggesting great potential as a vehicle for releasing bioactive compounds into food.
RESUMO
Films obtained by casting, starting from conventional emulsions (CE), nanoemulsions (NE) or their gels, which led to different structures, with the aim of explore the relationship between structure and physical properties, were prepared. Sodium caseinate was used as the matrix, glycerol as plasticizer, glucono-delta-lactone as acidulant to form the gels, and TiO2 nanoparticles as reinforcement to improve physical behavior. Structural characterization was performed by SAXS and WAXS (Small and Wide Angle X-ray Scattering, respectively), combined with confocal and scanning electron microscopy. The results demonstrate that the incorporation of the lipid phase does not notably modify the mechanical properties of the films compared to solution films. Films from NE were more stable against oil release than those from CE. Incorporation of TiO2 improved mechanical properties as measured by dynamical mechanical analysis (DMA) and uniaxial tensile tests. TiO2 macroscopic spatial distribution homogeneity and the nanostructure character of NE films were confirmed by mapping the q-dependent scattering intensity in scanning SAXS experiments. SAXS microscopies indicated a higher intrinsic homogeneity of NE films compared to CE films, independently of the TiO2 load. NE-films containing structures with smaller and more homogeneously distributed building blocks showed greater potential for food applications than the films prepared from sodium caseinate solutions, which are the best known films.
Assuntos
Caseínas/química , Nanocompostos/química , Nanopartículas/química , Fenômenos Físicos , Titânio/química , Emulsões/química , Manipulação de Alimentos , Glicerol , Fenômenos Mecânicos , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Permeabilidade , Plastificantes/química , Espalhamento a Baixo Ângulo , Resistência à Tração , Termogravimetria , Difração de Raios XRESUMO
Considering the polysaccharide composition and 32% of crystallinity of the water insoluble fiber extracted from corn husk (CHF) agricultural residue, its filler performance as water vapor permeability (WVP) and mechanical modifier in edible films based on commercial low methoxyl pectin (LMP) was evaluated (0, 1, 3, 5, 8% concentrations). The 53-µm-CHF carried phenolics and carotenes, and composites showed antioxidant capacity. Homogeneous films with a continuous LMP matrix were obtained. The 5%-CHF composite showed the highest surface contact angle (44°) and tensile strength, without change in elongation, while WVP was decreased in the 3-8% CHF-LMP-films. The latter was ascribed to the CHF-filler crystallinity whereas the improvement in mechanical performance and contact angle was attributed to a CHF-interconnected network formed at 5%-CHF critical concentration. Corn husk residue can be utilized as a source of fibers for material development. Composites with enhanced performance can be an antioxidant strategy at food interfaces.
Assuntos
Embalagem de Alimentos , Pectinas/química , Resistência à Tração , Zea mays , PermeabilidadeRESUMO
Edible films are an alternative to the traditional methods of food preservation. Agro-industry produces big amounts of by-products which could be utilized as raw materials for the production of valuable products. In the present work, banana peelpowder and banana peel films were elaborated. Banana peel powder was characterized by the total starch and apparent amylose content together with solubility index and swelling power. Tension resistance, water vapor permeability, opacity, solubility and thickness were measured on the edible films of the present work. Banana peel powder showed appreciable amounts of starch (38.11% ± 3.9) an apparent amylose (42.22% ± 2.18). Therefore banana peel could be utilized on the elaboration of edible films. However, banana peel powder showed low values of solubility (11.41% ± 0.27) and swelling power (4.83% ± 0.15). Physical characteristics of edible films based on banana peel were similar to those produced with starch only, exceptuating water vapor permeability
Las películas comestibles son una alternativa cada vez más estudiada como método de conservación de alimentos. La agroindustria genera una importante cantidad de residuos con gran potencial para ser transformados en productos con valor comercial. En el presente trabajo se elaboró harina de cáscara de plátano y películas a partir de la misma. Se caracterizó la harina de corteza de plátano a través de su contenido de almidón total, amilosa aparente, índice de solubilidad y poder de hinchamiento y a las películas se evaluó la resistencia a la tensión, permeabilidad al vapor de agua, opacidad, solubilidad y espesor. La harina de cáscara de plátano presentó un importante contenido de almidón (38.11% ± 3.9) y amilosa aparente (42.22% ± 2.18), determinándose que es un material adecuado para elaborar recubrimientos comestibles. Sin embargo, presenta bajos valores de solubilidad (11.41% ± 0.27) y poder de hinchamiento (4.83% ± 0.15). Las características físicas de las películas comestibles elaboradas demostraron ser similares a los resultados obtenidos en recubrimientos de almidón puro, a excepción de la permeabilidad al vapor de agua.
Assuntos
Permeabilidade , Vapor , Indústria Alimentícia , Musa , Conservação de AlimentosRESUMO
This study investigated the physicochemical and mechanical properties of a novel edible film based on chia mucilage (CM) hydrocolloid. CM (1% w/v) films were prepared by incorporation of three concentrations of glycerol (25%, 50%, and 75% w/w, based on CM weight). As glycerol concentration increased, water vapor permeability (WVP), elongation at break (EB), and water solubility of CM films increased while their tensile strength (TS), and Young's modulus (YM) decreased significantly (p<0.05). CM films containing a high concentration of glycerol were slightly reddish and yellowish in color but still had a transparent appearance. CM films exhibited excellent absorption of ultraviolet light, and good thermal stability. The scanning electron micrographs showed that all CM films had a uniform appearance. This study demonstrated that the chia mucilage hydrocolloid has important properties and potential as an edible film, or coating.
Assuntos
Materiais Biocompatíveis/química , Crioprotetores/farmacologia , Glicerol/farmacologia , Mucilagem Vegetal/química , Plantas Comestíveis/química , Salvia/química , Sementes/química , Permeabilidade , Plantas Comestíveis/efeitos dos fármacos , Salvia/efeitos dos fármacos , Solubilidade , Vapor , Resistência à TraçãoRESUMO
As propriedades de barreira à umidade de embalagens plásticas para produtos oftálmicos de capacidade nominal de 20 mL e terminação 15 mm nos formatos cilíndrico e oval, de diferentes composições (100% Polietileno de Baixa Densidade (PEBD), 100% Polipropileno (PP) e blendas com percentuais 10% e 40% de Polietileno de Alta Densidade (PEAD) em PEBD), foram estudadas neste trabalho. Foi verificada também a influência do batoque gotejador (de maior ou menor orifício de dosagem) e a influência do fechamento na taxa de transmissão de vapor d'água. O trabalho foi conduzido sob duas condições de estocagem a 25 ºC/40% UR e a 40 ºC/75% UR. Verificou-se que o diâmetro do orifício gotejador não interferiu significativamente na perda de peso da embalagem avaliada a 25 ºC/40% UR. Sob a condição de estocagem a 40 ºC/75% UR verificou-se um aumento da taxa de transmissão de vapor d'água das embalagens comparativamente as mesmas embalagens avaliadas a 25 ºC/40% UR. O sistema de fechamento não favoreceu um acréscimo significativo da taxa de transmissão de vapor d'água, o que indica que a permeação ocorreu principalmente através do corpo da embalagem plástica. A propriedade de barreira foi influenciada pela composição da embalagem plástica chegando a uma redução média de 47% na taxa de transmissão de vapor d'água para a embalagem de PEBD com 40% PEAD em relação à embalagem com100% PEBD de formato cilíndrico. Verificou-se ainda que o formato oval, por apresentar uma maior área superficial exposta comparativamente à embalagem de formato cilíndrico, com regiões de menor espessura de parede, pode favorecer um ligeiro aumento da taxa de transmissão de vapor d'água da embalagem...
The moisture barrier properties of plastic ophthalmic product bottles of nominal capacity 20 mL and finish diameter 15 mm, in cylindrical and oval shapes, with various compositions (100% Low Density Polyethylene(LDPE), 100% polypropylene (PP) and blends with10% and 40% High Density Polyethylene (HDPE) in LDPE), were assessed in this study. The effects of the drop hole size (higher or lower dosage diameter) and the screw cap on the Water Vapor Transmission Rate (WVTR) were also assessed. This study was conducted under two conditions of storage, at 25 °C/40% RH and 40 °C/75% RH. It was observed that the drop hole diameter did not influence significantly the weight loss of the container at 25 °C/40% RH, whereas at 40°C/75% RH, the WVTR of the container was higher than that of the same package at 25 °C/40% RH.The screw cap did not significantly affect the WVTR, indicating that the permeation occurred primarily through the plastic body. The barrier property was influenced by the composition of the plastic container; thus, compared to LDPE, there was a mean reduction of 47% in the WVTR of LDPE blended with 40% HDPE, when both bottles were cylindrical. It was found that the oval shape, because of the larger exposed surface area relative to the cylindrical shape, as well as the presence of regions of thinner wall, can favor a slight increase in the WVTR of the bottle...
Assuntos
Embalagem de Medicamentos , Umidade , Soluções Oftálmicas/análise , Vapor/efeitos adversosRESUMO
Edible coatings were produced using cassava starch (2% and 3% w/v) containing cinnamon bark (0.05% to 0.30% v/v) or fennel (0.05% to 0.30% v/v) essential oils. Edible cassava starch coating at 2% and 3% (w/v) containing or not containing 0.30% (v/v) of each essential oils conferred increased in water vapor resistance and decreased in the respiration rates of coated apple slices when compared with uncoated fruit. Cassava starch coatings (2% w/v) added 0.10% or 0.30% (v/v) fennel or cinnamon bark essential oils showed antioxidant capacity, and the addition of 0.30% (v/v) of each essential oil demonstrated antimicrobial properties. The coating containing cinnamon bark essential oil showed a significant antioxidant capacity, comparing to fennel essential oil. Antimicrobial tests showed that the addition of 0.30% (v/v) cinnamon bark essential oil to the edible coating inhibited the growth of Staphylococcus aureus and Salmonella choleraesuis, and 0.30% fennel essential oil inhibited just S. aureus. Treatment with 2% (w/v) of cassava starch containing 0.30% (v/v) of the cinnamon bark essential oil showed barrier properties, an antioxidant capacity and microbial inhibition.
Assuntos
Fast Foods/análise , Conservação de Alimentos , Frutas/química , Malus/química , Manihot/química , Óleos Voláteis/química , Amido/química , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Antioxidantes/química , Antioxidantes/metabolismo , Dióxido de Carbono/metabolismo , Fast Foods/microbiologia , Manipulação de Alimentos , Embalagem de Alimentos , Frutas/metabolismo , Frutas/microbiologia , Glicerol/química , Glicerol/metabolismo , Malus/metabolismo , Malus/microbiologia , Viabilidade Microbiana , Óleos Voláteis/metabolismo , Permeabilidade , Salmonella enterica/crescimento & desenvolvimento , Salmonella enterica/metabolismo , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo , Amido/metabolismo , Vapor , Propriedades de SuperfícieRESUMO
Rice and banana flours are inexpensive starchy materials that can form films with more improved properties than those made with their starch because flour and starch present different hydrophobicity. Montmorillonite (MMT) can be used to further improve the properties of starch-based films, which has not received much research attention for starchy flours. The aim of this work was to evaluate the mechanical and barrier properties of nanocomposite films of banana and rice flours as matrix material with addition of MMT as a nanofiller. MMT was modified using citric acid to produce intercalated structures, as verified by the X-ray diffraction pattern. The intercalated MMT was blended with flour slurries, and films were prepared by casting. Nanocomposite films of banana and rice flours presented an increase in the tensile at break and elongation percentage, respectively, more than their respective control films without MMT. This study showed that banana and rice flours could be alternative raw materials to use in making nanocomposite films.