RESUMO
BACKGROUND: The use of damaged beans for starch isolation comprises an end-use alternative for a product that is not accepted by the consumer. For that reason, isolation and modification of Carioca bean starch should be explored and evaluated as a suitable source for biodegradable material. The present study aimed to evaluate the synergism of physical and chemical modifications on Carioca bean starch with respect to improving the properties of biodegradable films. A heat-moisture treatment (HMT) followed by oxidation by sodium hypochlorite was performed and vice versa. RESULTS: Synergism was noted in the starch properties compared to the single modification. When the oxidation was applied first, a higher amylose and carbonyl content was noted. HMT, isolated and as a second modification, caused a more pronounced effect on viscosity profile than the oxidized starch, with an increase in paste temperature and a decrease in viscosity, breakdown and final viscosity. CONCLUSION: The results obtained in the present study reflect a decrease in water vapor permeability, although a higher tensile strength was noted when oxidation was applied, as a single and as a first modification. © 2020 Society of Chemical Industry.
Assuntos
Fabaceae/química , Extratos Vegetais/química , Amido/química , Oxirredução , Permeabilidade , Extratos Vegetais/isolamento & purificação , Amido/isolamento & purificação , Vapor/análise , Resistência à Tração , ViscosidadeRESUMO
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
BACKGROUND: Active packaging containing natural flavonoid has recently emerged as a result of its potential to inhibit the oxidation of foods by interacting with it and/or its surrounding environment, with the aim of counteracting oxidation reactions and extending the shelf-life of foods. The plant Spondias purpurea L. is widely found in northeastern Brazil and is known to contain bioactive flavonoids. The present study aimed to obtain a flavonoid-rich fraction from the pulp of S. purpurea L. and incorporate it into the cellulose acetate film to obtain biodegradable films with antioxidant properties. RESULTS: The fractionation in SiO2 open-column chromatography of the S. purpurea pulp crude extract furnished an antioxidant active fraction containing the flavonols quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside as the major compounds. This active fraction was incorporated (10, 20 and 30 g kg-1 ) into the substance produced with the casting method for cellulose acetate films. The films produced were characterized concerning mechanical properties, water vapor permeability (WVP) and antioxidant activity. CONCLUSION: The incorporation of the active flavonoid fraction from S. purpurea in the cellulose acetate films decreases WVP and elongation at break, at the same time as increasing antioxidant activity, tensile strength and elastic modulus. Thus, the S. purpurea pulps may be an alternative as a source of antioxidants for use in cellulose acetate films. © 2020 Society of Chemical Industry.
Assuntos
Anacardiaceae/química , Antioxidantes/química , Celulose/análogos & derivados , Flavonóis/química , Manipulação de Alimentos/instrumentação , Extratos Vegetais/química , Brasil , Celulose/química , Oxirredução , Permeabilidade , Dióxido de Silício/química , Vapor/análise , Resistência à TraçãoRESUMO
In this study, the effect of chia mucilage (CM) and protein concentrate (CPC) contents on the physicochemical, thermal, mechanical, and optical characteristics of developed films was evaluated. Films were prepared dissolving CM:CPC mixtures (1% w/v) in seven ratios (0:1, 1:4, 1:2, 1:1, 2:1, 4:1, 1:0). Microstructure of treatments with higher CM revealed the formation of polysaccharide granules. A semicrystalline behavior was manifested in 1:0, which decreased as CPC content in the formulations increased. Contact angle values obtained for 1:1 and 2:1 were the highest (61.24° and 62.44°), evidencing less affinity to water than other films. TGA analysis suggest that films showed thermal stability at less than 225 °C. Melting temperatures above 85 °C were found for all films in the evaluated range (50 °C to 200 °C) of DSC analysis. Higher CM concentrations in films increased the force required to break them (13.5 MPa) and their elongation capacity (5.20%). As the CM ratio in formulations was increased, the color difference was lower (ΔE = 27.45), water vapor permeability was higher (10.9 × 10-11 g/m·s·Pa), but transparency was statistically the same for all treatments (6.62 to 7.26). After analyzing all films properties, 2:1 formulation corresponding to 25:75% w/v mixtures of CM:CPC would be the best option for use in food packaging.
Assuntos
Embalagem de Alimentos/instrumentação , Extratos Vegetais/química , Mucilagem Vegetal/química , Proteínas de Plantas/química , Salvia/química , Plásticos Biodegradáveis/química , Fenômenos Biomecânicos , Temperatura Alta , Permeabilidade , Sementes/química , Vapor/análiseRESUMO
In this work, the influence of the method of processing on phenolic composition and the in vitro antioxidant activity (AOX) of grape juices was studied. The classic methods of producing "Hot Press" (HP), "Hot Break" (HB), and "Cold Press" (CP), and an artisanal method using steam were compared. Among the methods of elaboration of evaluated grape juices, those that heated the grape showed higher content of bioactive phenolics and AOX. The artisanal method using steam presented acceptable bioactive content and could be simple alternative for grape juice production. The main bioactive compounds quantified in the studied juices were procyanidin B1, quercetin-3-pyranoside, chlorogenic acid, malvidin-3-glucoside, cyanidin-3-glucoside, and petunidin-3-glucoside. These were correlated by principal component analysis (PCA) with the antioxidant activity. The characteristics obtained from the different juice elaboration methods demonstrate that the HB method was responsible for the greatest extraction of bioactive compounds from the grapes. PRACTICAL APPLICATIONS: Worldwide consumption of grape juice has been increasing. The factors that have contributed to this growth include the good sensory acceptance and the nutritional appeal related to bioactive compounds. The bioactive compounds of grape juice are mainly flavonoids and phenolic acids, and several factors exert influence on the phenolic composition of this beverage, among them, the method of elaboration. The present work presents new information on the influence of grape juice processing methods on the profile of bioactive compounds of nutritional interest and contributes to improvements in the production processes of this beverage.
Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Fenóis/química , Vitis/química , Frutas/química , Temperatura Alta , Vapor/análiseRESUMO
Every year, the residues generated by the disposal of packaging materials produced from fossil fuels have been growing, denoting a major environmental problem that can be mitigated by the development of biodegradable materials from natural polymers, particularly edible films. This work aimed at the development of pectin films added by cupuassu puree and chitosan nanoparticles and to evaluate the improvement of the physical-mechanical performance of the composite films. The nanostructures displayed an average size of 110 nm and a zeta potential of approximately +40 mV. The films were produced by casting, and they exhibited manageability, homogeneity, and continuity. Based upon the mechanical analysis of maximum stress and elongation, it was concluded that the nanoparticles functioned as fillers, increasing the toughness of the pectin films. Water vapor permeability assays demonstrated that the nanostructured films containing cupuassu exhibited improved barrier properties. The glass transition temperature of the films was not strongly affected by the addition of nanoparticles. Conversely, the initial degradation temperature decreased with the addition of nanoparticles and cupuassu puree. The outcomes of this research pave a new route for the development of nonconventional food packaging materials.
Assuntos
Cacau/química , Quitosana/química , Embalagem de Alimentos/instrumentação , Nanopartículas/química , Pectinas/química , Extratos Vegetais/química , Polímeros/química , Permeabilidade , Polímeros/síntese química , Vapor/análiseRESUMO
BACKGROUND: Starches from four common bean genotypes were characterized and used in the production of biodegradable films. Starches were characterized by their swelling power, solubility, amylose content, granule morphology, relative crystallinity, thermal and pasting properties, and susceptibility to α-amylase hydrolysis. Films were characterized according to their morphology, mechanical and water vapor barrier properties, whiteness and opacity. RESULT: Depending on the common bean genotype, a great variation on starch properties was found, which, in turn, clearly impacted on the characteristics of the starch-based films. Starches from BRS Pitanga and BRS Pérola genotypes exhibited the highest amylose content and the lowest swelling capabilities. Bean starch from the IPR Uirapuru genotype presented granules with an irregular surface and shape. Starches from IPR Uirapuru and BRS Estilo genotypes provided well-structured biodegradable films, without the occurrence of fissures or cracks. Moreover, starch films containing starch from BRS Estilo genotype exhibited the highest flexibility, permeability and solubility. CONCLUSION: The morphological, mechanical and water vapor barrier properties of films elaborated with common bean starch vary greatly as a function of the bean genotype used for starch production. © 2018 Society of Chemical Industry.
Assuntos
Fabaceae/genética , Extratos Vegetais/química , Amido/química , Fabaceae/química , Fabaceae/classificação , Genótipo , Hidrólise , Permeabilidade , Solubilidade , Vapor/análiseRESUMO
Constructed wetlands systems demand preliminary and primary treatment to remove solids present in greywater (GW) to avoid or reduce clogging processes. The current paper aims to assess hydraulic and hydrological behavior in an improved constructed wetland system, which has a built-in anaerobic digestion chamber (AnC), GW is distributed to the evapotranspiration and treatment tank (CEvaT), combined with a subsurface horizontal flow constructed wetland (SSHF-CW). The results show that both the plants present in the units and the AnC improve hydraulic and volumetric efficiency, decrease short-circuiting and improve mixing conditions in the system. Moreover, the hydraulic conductivity measured on-site indicates that the presence of plants in the system and the flow distribution pattern provided by the AnC might reduce clogging in the SSHF-CW. It is observed that rainfall enables salt elimination, thus increasing evapotranspiration (ET), which promotes effluent reduction and enables the system to have zero discharge when reuse is unfeasible.
Assuntos
Produtos Domésticos , Hidrologia , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Áreas Alagadas , Conservação dos Recursos Naturais/métodos , Humanos , Hidrologia/métodos , Plantas , Vapor/análise , Instalações de Eliminação de Resíduos , Águas Residuárias/química , Poluentes da Água/isolamento & purificaçãoRESUMO
Post-processing evolution of the functional properties of soybean protein concentrate (SPC) films, plasticized with varying levels of glycerol and processed by compression molding, was examined over a period of 90days. Films stored in the glassy state (25±2°C and 65±2% relative humidity) lost glycerol and water over time, as determined by gas chromatography and the decline in moisture content. SPC films plasticized with 40-50% glycerol showed a time-dependent increment of the elastic modulus and the tensile strength. In turn, the elongation, barrier properties, soluble mass and opacity of these films varied marginally with time. By contrast, films with 30% glycerol lost the most moisture and their elongation was reduced significantly, while water vapor permeability slightly increased with aging. The performance of aged films resulted from the balance between plasticizer and water loss, and the progressive replacement of unordered structures by intermolecular hydrogen bonded ß-sheets and aggregates.
Assuntos
Proteínas de Soja/química , Módulo de Elasticidade , Embalagem de Alimentos/instrumentação , Glicerol/química , Peso Molecular , Permeabilidade , Plastificantes/química , Vapor/análise , Resistência à TraçãoRESUMO
Biocomposites films based on thermoplastic corn starch (TPS) containing 0.5% w/w fibrous residue from Pachyrhizus ahipa starch extraction (PASR) were obtained by melt-mixing and compression molding. PASR is mainly constituted by remaining cell walls and natural fibers, revealed by Scanning Electron Microscopy (SEM). Chemical composition of the residue indicated that fiber and starch were the principal components. Biocomposites thermo-stability was determined by Thermo-Gravimetric Analysis. A continuous PASR-TPS interface was observed by SEM, as a result of a good adhesion of the fibrous residue to starch matrix. Likewise, films containing PASR presented fewer superficial cracks than TPS ones, whereas their fracture surfaces were more irregular. Besides, the presence of PASR increased starch films roughness, due to fibers agglomerates. Films reinforced with PASR showed significantly lower water vapor permeability (WVP). In addition, PARS filler increased maximum tensile strength and Young's modulus of TPS films, thus leading to more resistant starch matrixes.