Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Foods ; 13(8)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38672881

RESUMO

Quercetin (Q) dietary supplements exhibit poor oral bioavailability because of degradation throughout gastrointestinal digestion (GD), which may be overcome using mesoporous silica particles (MSPs) as an oral delivery system (ODS). This study aimed to elucidate the effect of the functionalization of MSPs with amine-(A-MSP), carboxyl-(C-MSP), or thiol-(T-MSP) groups on their efficiency as a quercetin ODS (QODS). The type and degree of functionalization (DF) were used as factors in an experimental design. The Q-loaded F-MSP (F-MSP/Q) was characterized by gas physisorption analysis, loading capacity (LC), and dynamic light scattering and kinetics of Q release at gastric and intestinal pHs. Antioxidant capacity and Q concentration of media containing F-MSP/Q were evaluated after simulated GD. A-MSP showed the highest LC (19.79 ± 2.42%). C-MSP showed the lowest particle size at pH 1.5 or 7.4 (≈200 nm). T-MSP exhibited the maximum Q release at pH 7.4 (11.43%). High DF of A-MSP increased Q retention, regardless of pH. A-MSP preserved antioxidant capacity of Q-released gastric media (58.95 ± 3.34%). Nonetheless, MSP and F-MSP did not protect antioxidant properties of Q released in intestinal conditions. C-MSP and T-MSP showed essential features for cellular uptake and Q release within cells that need to be assessed.

2.
ACS Omega ; 8(45): 42787-42796, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38024774

RESUMO

ζ-potential and Z-average were determined on film-forming solutions of bitter vetch-levan-based films prepared at different ratios in the absence and presence of glycerol as a plasticizer. The casting method was used to obtain manageable films. The results revealed that levan increases the elongation at break of bitter vetch protein films and reduces the tensile strength. The optimal result was obtained through the film that was prepared with the ratio of 50% bitter vetch proteins and 50% levan, in terms of mechanical properties. The surfaces of the prepared films appeared to be more compact and smooth. On increasing the glycerol concentration in the bitter vetch protein-levan films, the oxygen and water vapor permeability increased compared to the control (P < 0.05). Based on the overall results, the reinforcement of bitter vetch proteins with levan at a ratio of 1:1 represents optimal film properties in the presence of a low concentration of glycerol. The proposed film is suggested as an innovative packaging system for beef meat to preserve its quality over time.

3.
Foods ; 12(7)2023 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-37048228

RESUMO

The research objective was to investigate the morpho-rheological, chemical, and structural changes of dough and Neapolitan pizza TSG as the leavening time varies and to evaluate their effects on the digestibility of starch and on the formation of acrylamide during baking. Pizza dough leavening was monitored for 48 h at 22 °C/80% RH, and the analyses were conducted at selected leavening times (0, 4, 8, 16, 24, and 48 h). It was observed that in 30 h the volume tripled and the viscoelastic dough relaxed in the first 4 h, as evidenced by the lower value of the relaxation percentage "a" and the higher rate of decay "b", associated with a high value of the compression work, indicating the presence of a very strong gluten mesh. In the following hours, the dough lost elasticity, and in fact, the G' modulus decreased due to the weakening of the weak interactions between the gluten proteins and the starch. This suggests that a long leavening improved the extensibility of the pizza disc, facilitating the action of the pizza maker. Thermal (TGA and DSC) and morphological (SEM) analyses evidenced the highest water removal rate from the dough, a wider starch gelatinization temperature range, a ∆H of 0.975 ± 0.013 J/g, and a more open and weak gluten structure in dough balls leavened for 16 h. As the leavening time increased, both dough and pizza base samples showed an increase in reducing sugars and free amino groups, while the rapidly digestible starch decreased in the dough following the metabolism of the yeasts and increased in the pizza base due to the starch gelatinization that occurs during baking, which makes it much more susceptible to α-amylase. Finally, the levels of acrylamide remained at the same values despite the higher availability of reducing sugars and its precursors during leavening.

4.
Mar Drugs ; 21(3)2023 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-36976239

RESUMO

This study investigates the potential of utilizing three food wastes: cheese whey (CW), beet molasses (BM), and corn steep liquor (CSL) as alternative nutrient sources for the cultivation of the diatom Phaeodactylum tricornutum, a promising source of polyunsaturated eicosapentaenoic acid (EPA) and the carotenoid fucoxanthin. The CW media tested did not significantly impact the growth rate of P. tricornutum; however, CW hydrolysate significantly enhances cell growth. BM in cultivation medium enhances biomass production and fucoxanthin yield. The optimization of the new food waste medium was conducted through the application of a response surface methodology (RSM) using hydrolyzed CW, BM, and CSL as factors. The results showed a significant positive impact of these factors (p < 0.005), with an optimized biomass yield of 2.35 g L-1 and a fucoxanthin yield of 3.64 mg L-1 using a medium composed of 33 mL L-1 of CW, 2.3 g L-1 of BM, and 2.24 g L-1 of CSL. The experimental results reported in this study showed that some food by-products from a biorefinery perspective could be utilized for the efficient production of fucoxanthin and other high-added-value products such as eicosapentaenoic acid (EPA).


Assuntos
Queijo , Diatomáceas , Ácidos Graxos Ômega-3 , Microalgas , Eliminação de Resíduos , Ácidos Graxos Ômega-3/metabolismo , Ácido Eicosapentaenoico , Soro do Leite , Diatomáceas/metabolismo , Antioxidantes/metabolismo , Proteínas do Soro do Leite/metabolismo , Microalgas/metabolismo
5.
Int J Mol Sci ; 23(18)2022 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-36142471

RESUMO

The increase in consumer demand for more sustainable packaging materials represents an opportunity for biopolymers utilization as an alternative to reduce the environmental impact of plastics. Cellulose (C) and chitosan (CH) are attractive biopolymers for film production due to their high abundance, biodegradability and low toxicity. The objective of this work was to incorporate cellulose nanocrystals (NC) and C extracted from corn cobs in films added with chitosan and to evaluate their properties and biodegradability. The physicochemical (water vapor barrier, moisture content, water solubility and color) and mechanical properties of the films were evaluated. Component interactions using Fourier-transform infrared (FTIR) spectroscopy, surface topography by means of atomic force microscopy (AFM), biodegradability utilizing a fungal mixture and compostability by burying film discs in compost were also determined. The C-NC-CH compared to C-CH films presented a lower moisture content (17.19 ± 1.11% and 20.07 ± 1.01%; w/w, respectively) and water vapor permeability (g m−1 s−1 Pa−1 × 10−12: 1.05 ± 0.15 and 1.57 ± 0.10; w/w, respectively) associated with the NC addition. Significantly high roughness (Rq = 4.90 ± 0.98 nm) was observed in films added to NC, suggesting a decreased homogeneity. The biodegradability test showed larger fungal growth on C-CH films than on CH films (>60% and <10%, respectively) due to the antifungal properties of CH. C extracted from corn cobs resulted in a good option as an alternative packaging material, while the use of NC improved the luminosity and water barrier properties of C-CH films, promoting strong interactions due to hydrogen bonds.


Assuntos
Quitosana , Nanopartículas , Antifúngicos , Biopolímeros , Celulose/química , Quitosana/química , Embalagem de Alimentos/métodos , Permeabilidade , Plásticos , Vapor , Resistência à Tração , Zea mays/química
6.
Foods ; 11(10)2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35627028

RESUMO

Functional and enriched foods are increasingly in demand in the global market due to their benefits for human health and their prevention of several diseases. The aim of this work was to develop a functional pizza base, produced in the Neapolitan style, exploiting the beneficial properties of jujube. The jujube fruit is rich in phenolic compounds with high antioxidant activity and represents a good candidate for functional food development. The doughs were prepared by replacing the wheat flour with 2.5%, 5.0%, and 7.5% (w/w) of Ziziphus jujube powder (ZJP) and were subsequently cooked. Chemical analyses showed that both total phenolic compounds and antioxidant activity grew with the increase of ZJP. The addition of ZJP darkened the pizza base and raised its hardness, gumminess, and chewiness. However, no difference was found in the springiness and cohesiveness of the samples with or without ZJP. These results suggest that jujube powder can be successfully introduced into pizza dough as a functional ingredient.

7.
Int J Mol Sci ; 23(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35408966

RESUMO

Plastic pollution is currently one of the most pressing environmental problems, especially in countries with a low recycling rate that is mainly due to the insufficient collection of plastic waste [...].


Assuntos
Gerenciamento de Resíduos , Embalagem de Medicamentos , Plásticos , Embalagem de Produtos , Reciclagem
8.
Polymers (Basel) ; 14(6)2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35335520

RESUMO

Since the potentialities of applications of low molecular weight poly-γ-glutamic acid (γ-PGA) chains have been so far only partially explored, the separation of diverse molecular families of them, as well as their characterization for potential bioactivity and ability to form films, were investigated. Two different approaches based on organic solvent precipitation or on ultra- and nano-filtration membrane-based purification of inexpensive commercial material were employed to obtain size-specific γ-PGA fractions, further characterized by size exclusion chromatography equipped with a triple detector array and by ultra-high-performance liquid chromatography to assess their average molecular weight and their concentration. The γ-PGA low molecular weight fractions, purified by ultra-filtration, have been shown both to counteract the desiccation and the oxidative stress of keratinocyte monolayers. In addition, they were exploited to prepare novel hydrocolloid films by both solvent casting and thermal compression, in the presence of different concentrations of glycerol used as plasticizer. These biomaterials were characterized for their hydrophilicity, thermal and mechanical properties. The hot compression led to the attainment of less resistant but more extensible films. However, in all cases, an increase in elongation at break as a function of the glycerol content was observed. Besides, the thermal analyses of hot compressed materials demonstrated that thermal stability was increased with higher γ-PGA distribution po-lymer fractions. The obtained biomaterials might be potentially useful for applications in cosmetics and as vehicle of active molecules in the pharmaceutical field.

9.
Foods ; 11(20)2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37430961

RESUMO

Basil (Ocimum basilicum L.) is an annual spicy plant generally utilized as a flavouring agent for food. Basil leaves also have pharmaceutical properties due to the presence of polyphenols, phenolic acids, and flavonoids. In this work, carbon dioxide was employed to extract bioactive compounds from basil leaves. Extraction with supercritical CO2 (p = 30 MPa; T = 50 °C) for 2 h using 10% ethanol as a cosolvent was the most efficient method, with a yield similar to that of the control (100% ethanol) and was applied to two basil cultivars: "Italiano Classico" and "Genovese". Antioxidant activity, phenolic acid content, and volatile organic compounds were determined in the extracts obtained by this method. In both cultivars, the supercritical CO2 extracts showed antiradical activity (ABTS●+ assay), caffeic acid (1.69-1.92 mg/g), linalool (35-27%), and bergamotene (11-14%) contents significantly higher than those of the control. The polyphenol content and antiradical activity measured by the three assays were higher in the "Genovese" cultivar than in the "Italiano Classico" cultivar, while the linalool content was higher (35.08%) in the "Italiano Classico" cultivar. Supercritical CO2 not only allowed us to obtain extracts rich in bioactive compounds in an environmentally friendly way but also reduced ethanol consumption.

10.
Mar Drugs ; 20(1)2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-35049894

RESUMO

Mozzarella stretching water (MSW) is a dairy effluent generated from mozzarella cheese production that does not have a real use and is destined to disposal, causing environmental problems and representing a high disposal cost for dairy producers. Spent brewery yeast (SBY) is another promising food waste produced after brewery manufacturing that could be recycled in new biotechnological processes. Aurantiochytrium mangrovei is an aquatic protist known as producer of bioactive lipids such as omega 3 long chain polyunsaturated fatty acids (ω3 LC-PUFA), in particular docosahexaenoic acid (DHA). In this work MSW and SBY have been used to formulate new sustainable growth media for A. mangrovei cultivation and production of DHA in an attempt to valorize these effluents. MSW required an enzymatic hydrolysis to enhance the biomass production. The new media obtained from hydrolysed MSW was also optimized using response surface methodologies, obtaining 10.14 g L-1 of biomass in optimized medium, with a DHA content of 1.21 g L-1.


Assuntos
Bebidas Alcoólicas , Indústria de Laticínios , Ácidos Graxos Ômega-3/metabolismo , Resíduos Industriais , Estramenópilas/metabolismo , Animais , Organismos Aquáticos , Ácidos Docosa-Hexaenoicos/metabolismo , Humanos , Avaliação de Programas e Projetos de Saúde
11.
Polymers (Basel) ; 12(12)2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33255710

RESUMO

Nanocrystalline cellulose (NC) and a lignin-containing fraction (LF) were obtained from egagropili, the so called sea balls produced from rhizome and stem fragments of Posidonia oceanica that accumulate in large amounts along the coastal beaches in the form of tightly packed and dry materials of various dimensions. Both egagropili fractions have been shown to be able to improve the physicochemical properties of biodegradable films prepared from protein concentrates derived from hemp oilseed cakes. These materials, manufactured with a biodegradable industrial by-product and grafted with equally biodegradable waste-derived additives, exhibited an acceptable resistance with a still high flexibility, as well as they showed an effective barrier activity against water vapor and gases (O2 and CO2). Furthermore, both NC and LF decreased film moisture content, swelling ability and solubility, thus indicating that both additives were able to improve water resistance of the hydrocolloid films. The exploitation of egagropili, actually considered only an undesirable waste to be disposed, as a renewable source of reinforcing agents to blend with different kinds of polymers is suggested.

12.
Int J Mol Sci ; 21(14)2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32668678

RESUMO

Oil-derived plastics are the most commonly used materials for packaging because of their features, low cost, and availability of resources for manufacturing [...].


Assuntos
Biopolímeros , Embalagem de Alimentos , Química Verde
13.
Polymers (Basel) ; 12(7)2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32698496

RESUMO

Commercial inexpensive preparations of poly-γ-glutamic acid were used to obtain films made with a polypeptide constituted by a single repeating unit. The homopolymer was characterized by 1H-NMR spectroscopy and thermogravimetry, as well as by zeta potential and Z-average measurements. Manipulatable materials were obtained by casting film-forming solutions prepared at pH values between 3.0 and 4.0 and containing extensively dialyzed samples of the commercial product. The analysis of the mechanical properties highlighted a marked extensibility and plasticity of the films obtained without plasticizer, even though the addition of low amounts of glycerol (1-4%) was able to further increase these features. The characterization of poly-γ-glutamic acid molecular species, performed by membrane ultrafiltration and size-exclusion chromatography, coupled with triple-detection analysis of the obtained fractions, suggested that biopolymer chain length is responsible not only for its capacity to form film, but also for conferring to the films different features depending on the homopolymer molecular weight.

14.
Int J Biol Macromol ; 161: 787-796, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32535208

RESUMO

Lignocellulosic raw materials are being utilised in many industrial sectors as a natural source of interesting biopolymers. In the present research, tomato plant agri-waste, were subjected to an enzymatic treatment (pectinase, hemicellulase, xylanase and laccase) with the aim of recovering polymeric matrices contained therein and obtain a good quality fibre. The cellulose content in the enzyme-treated fibres was enriched of 25% compared to the untreated, and a fair reduction in hemicellulose and lignin was registered. Morphological analyses at SEM demonstrated the cleanliness and fibrillation of fibres. Moreover, the thermal profile, water absorption and pulp viscosity of fibres was strongly affected by the composition changes. The paperboard manufactured from an enzymatically treated sample showed increased stiffness when subjected to tensile testing respect to the control. Therefore, the use of enzyme in fibre pulping has a potential application in the design of sustainable materials.


Assuntos
Glicosídeo Hidrolases/química , Lignina/química , Papel , Solanum lycopersicum/química
15.
Int J Mol Sci ; 21(3)2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32012882

RESUMO

Black biodegradable/edible protein-based films were prepared from defatted cake waste obtained from Nigella sativa (black cumin) seeds as by-product of oil extraction process. The effects of pH, glycerol concentrations, and transglutaminase-catalyzed protein cross-linking activity on the stability of film-forming solutions were studied to determine the best experimental conditions to produce handleable films. Proteins contained in the analyzed defatted cake were shown to be able to act as transglutaminase acyl donor and acceptor substrates being polymerized when incubated in vitro in the presence of the enzyme. Film-forming solutions containing 20% glycerol and casted at pH 8.0 after treatment with the enzyme gave rise to morphologically more homogeneous films possessing mechanical and barrier properties, as well as antimicrobial activity, compatible with their possible applications as food packaging materials and mulching sheets. These findings confirm the validity of the strategy to consider the seed oil processed cakes as protein-based renewable sources to produce not only fertilizers, animal feed, or culinary food but also further valuable products such as bioplastics.


Assuntos
Filmes Comestíveis , Embalagem de Alimentos/métodos , Nigella sativa/metabolismo , Proteínas de Plantas/metabolismo , Glicerol/química , Concentração de Íons de Hidrogênio , Óleos de Plantas/metabolismo , Transglutaminases/metabolismo
16.
Int J Mol Sci ; 18(11)2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-29117148

RESUMO

Edible films (EFs) have gained great interest due to their ability to keep foods safe, maintaining their physical and organoleptic properties for a longer time. The aim of this work was to develop EFs based on a chitosan-zein mixture with three different essential oils (EOs) added: anise, orange, and cinnamon, and to characterize them to establish the relationship between their structural and physical properties. The addition of an EO into an EF significantly affected (p < 0.05) the a* (redness/greenness) and b* (yellowness/blueness) values of the film surface. The EFs presented a refractive index between 1.35 and 1.55, and thus are classified as transparent. The physical properties of EFs with an added EO were improved, and films that incorporated the anise EO showed significantly lower water vapor permeability (1.2 ± 0.1 g mm h-1 m-2 kPa-1) and high hardness (104.3 ± 3.22 MPa). EFs with an added EO were able to inhibit the growth of Penicillium sp. and Rhizopus sp. to a larger extent than without an EO. Films' structural changes were the result of chemical interactions among amino acid side chains from zein, glucosamine from chitosan, and cinnamaldehyde, anethole, or limonene from the EOs as detected by a Raman analysis. The incorporation of an EO in the EFs' formulation could represent an alternative use as coatings to enhance the shelf life of food products.


Assuntos
Antifúngicos/química , Quitosana/química , Embalagem de Alimentos , Óleos Voláteis/química , Zeína/química , Acroleína/análogos & derivados , Acroleína/química , Derivados de Alilbenzenos , Anisóis/química , Cicloexenos/química , Limoneno , Penicillium/efeitos dos fármacos , Polímeros/farmacologia , Refratometria , Rhizopus/efeitos dos fármacos , Propriedades de Superfície , Terpenos/química
17.
Int J Mol Sci ; 18(5)2017 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-28489025

RESUMO

Zeta potential and nanoparticle size were determined on film forming solutions of native and heat-denatured proteins of bitter vetch as a function of pH and of different concentrations of the polyamines spermidine and spermine, both in the absence and presence of the plasticizer glycerol. Our results showed that both polyamines decreased the negative zeta potential of all samples under pH 8.0 as a consequence of their ionic interaction with proteins. At the same time, they enhanced the dimension of nanoparticles under pH 8.0 as a result of macromolecular aggregations. By using native protein solutions, handleable films were obtained only from samples containing either a minimum of 33 mM glycerol or 4 mM spermidine, or both compounds together at lower glycerol concentrations. However, 2 mM spermidine was sufficient to obtain handleable film by using heat-treated samples without glycerol. Conversely, brittle materials were obtained by spermine alone, thus indicating that only spermidine was able to act as an ionic plasticizer. Lastly, both polyamines, mainly spermine, were found able to act as "glycerol-like" plasticizers at concentrations higher than 5 mM under experimental conditions at which their amino groups are undissociated. Our findings open new perspectives in obtaining protein-based films by using aliphatic polycations as components.


Assuntos
Nanopartículas/química , Proteínas de Plantas/química , Plásticos/síntese química , Espermina/química , Plásticos/química , Polimerização , Sementes/química , Vicia/química
18.
J Food Sci ; 82(6): 1423-1432, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28493309

RESUMO

Fresh meat is a highly perishable food. This work aimed to evaluate the influence of Mexican oregano (Lippia graveolens Kunth) incorporated into active coatings (ACs) spread on fresh pork meat as free (FEO), nanoemulsified (NEO), and microencapsulated (MEO) essential oil (EO), on its microbiological, physicochemical and sensory properties during 15 d at 4 ± 1 °C. Thymol and γ-terpinene were identified in the EO. In vitro effect of 2.85 mg EO/cm2 was tested against Brochothrix thermosphacta, Micrococcus luteus, Lactobacillus plantarum, Pseudomonas fragi, and Salmonella Infantis. FEO antioxidant capacity (DPPH assay) was significantly higher than that of thymol, NEO and MEO (93.53%, 89.92%, 77.79%, and 78.50% inhibition, respectively), and similar to BHA (96.03%) and gallic acid (95.57%). FEO, NEO, and MEO ACs on meat caused growth inhibition of lactic acid bacteria (5 log population reduction) and Pseudomonas spp. (4 log reduction), whereas ≤1.5 log population reduction was observed for B. thermosphacta and Salmonella Infantis. Meat microbiota was more efficiently controlled by MEO than by FEO or NEO. ACs delayed lipid and oxymyoglobin oxidation of fresh pork meat. After 15 d of cold storage meat added with EO coatings was desirable for panelists, whereas untreated (UT) samples were undesirable. Active coatings are a significant alternative method for fresh meat preservation.


Assuntos
Microbiologia de Alimentos , Lippia/química , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Carne Vermelha/microbiologia , Animais , Composição de Medicamentos , Conservação de Alimentos/métodos , Humanos , México , Nanotecnologia , Óleos Voláteis/química , Óleos de Plantas/química , Suínos
19.
Int J Mol Sci ; 18(12)2017 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-29292733

RESUMO

Bitter vetch protein films containing positively charged spermidine, alone or with low amounts of glycerol, showed high tensile strength that progressively decreased by increasing the plasticizer concentration. Accordingly, lower film elongation at break and higher Young's module values were detected in the presence of the polyamine without or with small amounts of glycerol. These data suggest that spermidine not only acts as a plasticizer itself by ionically interacting with proteins, but that it also facilitates glycerol-dependent reduction of the intermolecular forces along the protein chains, consequently improving the film flexibility and extensibility. Thus, spermidine may be considered not only as a primary, but also as a secondary plasticizer because of its ability to enhance glycerol plasticizing performance. Such double behavior of the polyamine was confirmed by the film permeability tests, since spermidine increased the barrier properties to gases and water vapor, while glycerol emphasized this effect at low concentrations but led to its marked reversal at high concentrations. Film microscopic images also substantiated these findings, showing more compact, cohesive, and homogeneous matrices in all spermidine-containing films.


Assuntos
Proteínas de Plantas/química , Espermidina/química , Vicia/química , Glicerol/química , Proteínas de Plantas/ultraestrutura , Poliaminas/química , Sementes/química , Vapor , Resistência à Tração
20.
Carbohydr Polym ; 153: 222-228, 2016 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-27561490

RESUMO

Zeta potential and particle size were determined on pectin aqueous solutions as a function of pH and the effects of calcium ions, putrescine and spermidine on pectin film forming solutions and derived films were studied. Ca(2+) and polyamines were found to differently influence pectin zeta potential as well as thickness and mechanical and barrier properties of pectin films prepared at pH 7.5 either in the presence or absence of the plasticizer glycerol. In particular, Ca(2+) was found to increase film tensile strength and elongation at break only in the presence of glycerol and did not affect film thickness and permeability to both water vapor and CO2. Conversely, increasing polyamine concentrations progressively reduced film tensile strength and markedly enhanced film thickness, elongation at break and permeability to water vapor and CO2, both in the presence and absence of glycerol. Our findings indicate that polyamines give rise to a structural organization of the heteropolysaccharide different from that determined by calcium ions, previously described as "egg box" model, and suggest their possible application as plasticizers to produce pectin-based "bioplastics" with different features.


Assuntos
Plásticos Biodegradáveis/química , Conservação de Alimentos , Pectinas/química , Plastificantes/química , Poliaminas/química , Cálcio/química , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Glicerol/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Permeabilidade , Putrescina/química , Espermidina/química , Resistência à Tração , Água/química , Água/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...