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1.
Molecules ; 28(10)2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37241822

RESUMO

Phytochemicals are natural compounds found in plants that have potential health benefits such as antioxidants, anti-inflammatory and anti-cancer properties, and immune reinforcement. Polygonum cuspidatum Sieb. et Zucc. is a source rich in resveratrol, traditionally consumed as an infusion. In this study, P. cuspidatum root extraction conditions were optimized to increase antioxidant capacity (DPPH, ABTS+), extraction yield, resveratrol concentration, and total polyphenolic compounds (TPC) via ultrasonic-assisted extraction using a Box-Behnken design (BBD). The biological activities of the optimized extract and the infusion were compared. The optimized extract was obtained using a solvent/root powder ratio of 4, 60% ethanol concentration, and 60% ultrasonic power. The optimized extract showed higher biological activities than the infusion. The optimized extract contained 16.6 mg mL-1 resveratrol, high antioxidant activities (135.1 µg TE mL-1 for DPPH, and 230.4 µg TE mL-1 for ABTS+), TPC (33.2 mg GAE mL-1), and extraction yield of 12.4%. The EC50 value (effective concentration 50) of the optimized extract was 0.194 µg mL-1, which revealed high cytotoxic activity against the Caco-2 cell line. The optimized extract could be used to develop functional beverages with high antioxidant capacity, antioxidants for edible oils, functional foods, and cosmetics.


Assuntos
Fallopia japonica , Ultrassom , Humanos , Resveratrol/farmacologia , Antioxidantes/farmacologia , Fallopia japonica/química , Células CACO-2 , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Alimento Funcional
2.
Molecules ; 27(15)2022 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-35956854

RESUMO

This research developed model foods of gelatine-based gels, where carbohydrates from Agave tequilana Weber var. Azul (agave syrups or/and agave fructans) were incorporated into gel formulations as healthy sucrose and glucose substitutes. The sugars (sucrose and glucose) were substituted by agave carbohydrates (agave syrups and agave fructans), obtaining the subsequent gel formulations: 100% agave syrup (F2 gel), 100% agave fructan (F3 gel), and 50% agave syrup−50% agave fructan (F4 gel). The unsubstituted gel formulation was used as a control (F1 gel). The prebiotic activities, physical properties, thermal stability (HP-TLC), and texture of gelatine-based gels were evaluated. The gel formulations showed translucent appearances with approximately 36 g/100 g of water and water activities values between 0.823 and 0.929. The HP-TLC analysis validated that agave fructans did not hydrolyse during the thermal process of gels production. Gels produced with agave syrup and agave fructan (F2-F4 gels) provided higher hardness, gumminess, and springiness values (p < 0.05) than those produced with glucose and sucrose (F1 gel). Gelatine-based gel formulations displayed prebiotic activities correlated to the ability of Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus rhamnosus to use agave carbohydrates as carbon sources. Based on the prebiotic effect and physical and textural properties, the F2 and F4 gel formulations displayed the best techno-functional properties to produce gel soft candies.


Assuntos
Agave , Frutanos/análise , Gelatina , Géis , Glucose , Lactobacillus , Prebióticos/análise , Sacarose , Água
3.
Molecules ; 26(21)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34770801

RESUMO

Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, ß-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfume, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has biological activity relevant to human health, including antimicrobial, antioxidant, and insecticidal activity. The impacts of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the concentration of the main volatile compounds in clove essential oil and organic clove extracts are shown. Eugenol is the major compound, accounting for at least 50%. The remaining 10-40% consists of eugenyl acetate, ß-caryophyllene, and α-humulene. The main biological activities reported are summarized. Furthermore, the main applications in clove essential oil in the food industry are presented. This review presents new biological applications beneficial for human health, such as anti-inflammatory, analgesic, anesthetic, antinociceptive, and anticancer activity. This review aims to describe the effects of different methods of extracting clove essential oil on its chemical composition and food applications and the biological activities of interest to human health.


Assuntos
Óleo de Cravo/química , Óleo de Cravo/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Syzygium/química , Anti-Infecciosos , Anti-Inflamatórios , Antineoplásicos Fitogênicos , Antioxidantes , Fracionamento Químico/métodos , Óleo de Cravo/isolamento & purificação , Suplementos Nutricionais , Aditivos Alimentares , Avaliação do Impacto na Saúde , Humanos , Óleos Voláteis/isolamento & purificação , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Relação Estrutura-Atividade
4.
J Food Sci Technol ; 58(12): 4514-4523, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34629515

RESUMO

In this research, a supercritical CO2-ethanol extraction was optimized to obtain a green coffee oil rich in bioactive compounds. A face-centered central composite design was used to evaluate the effect of temperature (50-70 °C), extraction pressure (15.0-30.0 MPa), and cosolvent content (5-20%) on the extraction yield and total phenolic compound content of green coffee supercritical extract (GCSE). The experimental data were fitted to a second-order polynomial model. According to the statistical analyses, the lack of fit was not significant for either mathematical model. From the response surface plots, the extraction pressure and cosolvent content significantly impacted the extraction yield, while the total phenolic compound content was impacted by temperature and cosolvent content. The optimal conditions were a 20% cosolvent content, a pressure of 30 MPa, and a temperature of 62 °C, which predicted an extraction yield of 7.7% with a total phenol content of 5.4 mg gallic acid equivalent g GCSE-1. The bioactive compounds included 5-caffeoylquinic acid (11.53-17.91 mg g GCSE-1), caffeine (44.76-79.51 mg g GCSE-1), linoleic acid (41.47-41.58%), and palmitic acid (36.07-36.18%). Our results showed that GCSE has the outstanding chemical quality and antioxidant potential, suggesting that GCSE can be used as a functional ingredient.

5.
J Food Sci Technol ; 57(2): 549-556, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32116364

RESUMO

Ultrasonication technology was used to enhance the solubility and availability of lipophilic compounds as curcumin. This study aimed to know the optimal conditions to produce ultrasonication curcumin nanoemulsions stabilized with hydroxylated lecithin using response surface methodology and to evaluate some physical characteristics. Nanoemulsions were produced according to a Central Composite Face-center Design: surfactant oil ratio (SOR, 0.33-1.17), amplitude (A, 8-92%), and ultrasonication time (t, 2-18.4 min). Dynamic light scattering was used to measure the droplet size and polydispersity index of the nanoemulsions. Our results showed that a second-order polynomial function of amplitude and ultrasonication time model fitted well with the mean droplet size and polydispersity of the emulsions. Predicted droplet size was 122.2 nm and polydispersity index was 0.13 obtained at optimal conditions: SOR = 0.72, A = 92%, and t = 12 min. The nanoemulsions remained stable during 15 days of storage at 20 °C. Nanoemulsion remained stable to the aggregation in the pH range from 7.0 to 3.0, while the droplet size increased at lower pH values due to a loss of charge of the lecithin. Nanoemulsion applied in a sugar-beverage showed a yellow-green translucent color, showing better stability on the droplet size than the beverage with the coarse emulsion. Nanoemulsion could be used as a natural colorant in beverages.

6.
Exp Parasitol ; 201: 26-33, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31029699

RESUMO

The cattle tick Rhipicephalus (Boophilus) microplus is one of the most important ectoparasites for livestock in tropical and subtropical areas around the world. This tick economically impacts cattle production by reducing weight gain and milk production. Moreover, it is a vector of pathogens causing diseases such as babesiosis and anaplasmosis. Conventional tick control relies mainly on the use of chemical acaricides; however, their intensive use has led to the rapid appearance of resistant tick populations. It is therefore necessary to look for alternative tick control products. In that sense, plant extracts might represent a promising source of new acaricides. Previously, we reported a significant acaricide effect of essential oils from selected plant species. In the present study, we used a mixture design approach to develop phyto-formulations by combining individual essential oils. We produced several mixtures at 10% containing different proportions of individual essential oils (ranging from 0 to 1) from cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and allspice (Pimenta dioica) and tested their acaricidal activity against R. microplus ticks by means of larval packet test (LPT) and adult immersion test (AIT) assays. The optimal mixture predicted against R. microplus was composed of 66%, 17% and 17% of essential oils from C. zeylanicum, C. cyminum and P. dioica, respectively. We generated an estimated response surface contour plot that estimates 80%-100% acaricidal efficacy. In the optimal mixture 34 compounds were identified, which represent 98.65% of the total composition, with cinnamaldehyde (37.77%), ß-caryophyllene (13.92%), methyl eugenol (12.27%) and cuminaldehyde (8.99%) being the major components. Next, we developed emulsions by combining the optimal mixture with several surfactants and determined particle size, Zeta potential, stability and bioactivity. Emulsions containing 2% and 5% Tween 20 or Tween 80 remain stable after 14 days at 54 °C. Finally, optimized emulsion retained a high acaricidal activity against larval and adult R. microplus ticks. Taken together, our findings showed the usefulness of mixture design method for the development of essential oil mixtures with potent acaricidal activity. These formulations have the potential to successfully control tick infestations.


Assuntos
Doenças dos Bovinos/prevenção & controle , Óleos Voláteis , Extratos Vegetais , Rhipicephalus , Controle de Ácaros e Carrapatos/métodos , Infestações por Carrapato/veterinária , Acaricidas , Análise de Variância , Animais , Vetores Aracnídeos , Bovinos , Doenças dos Bovinos/parasitologia , Cinnamomum zeylanicum/química , Misturas Complexas/química , Cuminum/química , Emulsões/química , Feminino , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/química , Pimenta/química , Extratos Vegetais/química , Sementes/química , Infestações por Carrapato/prevenção & controle
7.
Int J Food Sci Nutr ; 70(1): 63-70, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29792361

RESUMO

The blueberry is recognised as a source of phenolic compounds that have beneficial effects on human health; however, they possess low bioavailability and can be degraded by gastrointestinal conditions. Encapsulation has been widely used to mitigate these disadvantages; Gum Arabic (GA) and Corn Syrup Solids (CSS) are common carriers used in this technique. The aim of this study was to evaluate the effect of Blueberry Extract (BE), carriers and their mixtures on the kinetic growth and maximal growth rate of probiotics and pathogenic bacteria. Kinetics were performed in MRS medium with and without a carbon source through Optical Density (OD) measurements and fitting these to the logistic model to compare the maximal growth rates (µmax) of the microorganisms. Each food component and its mixtures exert a different influence on the µmax of the bacteria studied (p < 0.05). This knowledge is important to improve the design of additives and functional foods.


Assuntos
Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Mirtilos Azuis (Planta)/química , Goma Arábica/farmacologia , Xarope de Milho Rico em Frutose/farmacologia , Extratos Vegetais/farmacologia , Probióticos , Carbono/metabolismo , Humanos , Cinética , Lactobacillus/efeitos dos fármacos , Lactobacillus/crescimento & desenvolvimento , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Fenóis/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento
8.
Molecules ; 24(19)2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31574952

RESUMO

Bioactive Phenols-loaded chitosan nanoparticles (PL-CNps) were developed by ionic gelation from Persian lemon (Citrus latifolia) waste (PLW) and chitosan nanoparticles. Response Surface Methodology (RSM) was used to determine the optimal Ultrasound-Assisted Extraction (UAE) conditions for the total phenolic compounds (TPC) recovery from PLW (58.13 mg GAE/g dw), evaluating the ethanol concentration, extraction time, amplitude, and solid/liquid ratio. Eight compounds expressed as mg/g dry weight (dw) were identified by ultra-performance liquid chromatography coupled photo diode array (UPLC-PDA) analysis: eriocitrin (20.71 ± 0.09), diosmin (18.59 ± 0.13), hesperidin (7.30 ± 0.04), sinapic acid (3.67 ± 0.04), catechin (2.92 ± 0.05), coumaric acid (2.86 ± 0.01), neohesperidin (1.63 ± 0.00), and naringenin (0.44 ± 0.00). The PL-CNps presented size of 232.7 nm, polydispersity index of 0.182, Z potential of -3.8 mV, and encapsulation efficiency of 81.16%. The results indicated that a synergic effect between phenolic compounds from PLW and chitosan nanoparticles was observed in antioxidant and antibacterial activity, according to Limpel's equation. Such results indicate that PLW in such bioprocesses shows excellent potential as substrates for the production of value-added compounds with a special application for the food industry.


Assuntos
Quitosana , Citrus/química , Nanopartículas , Fenóis/isolamento & purificação , Fenóis/farmacologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Fracionamento Químico , Quitosana/química , Cromatografia Líquida de Alta Pressão , Nanopartículas/química , Fenóis/química , Extratos Vegetais/química , Análise Espectral , Ondas Ultrassônicas
9.
Food Chem ; 453: 139644, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-38761735

RESUMO

This work developed and characterized the physicochemical properties of a type A gelatin and amidated low-methoxyl pectin complex coacervate (GA-LMAP-CC) hydrogel and evaluated its suitability for preserving the viability of probiotics under in vitro gastrointestinal conditions. The formation of GA-LMAP-CC was achieved via height electrostatic attraction at pH 3 and a mixing ratio of 1, exhibiting thermoreversible gel behavior. The hydrogel had a porosity of 44% and a water absorption capacity of up to 12 times. Water absorption profiles were obtained at different pH values (2, 5, and 7). The influence of GA-LMAP-CC depended on the medium, which controlled the hydration and water absorption rate. GA-LMAP-CC promoted the viability of B. longum BB536 and L. acidophilus strains under simulated gastrointestinal conditions, thereby enhancing their potential for intestinal colonization. The hydrogel has suitable properties for potential application in food and pharmaceutical areas to encapsulate and preserve probiotics.


Assuntos
Gelatina , Hidrogéis , Pectinas , Probióticos , Pectinas/química , Gelatina/química , Probióticos/química , Hidrogéis/química , Viabilidade Microbiana/efeitos dos fármacos , Lactobacillus acidophilus/química , Lactobacillus acidophilus/crescimento & desenvolvimento , Lactobacillus acidophilus/metabolismo , Bifidobacterium/crescimento & desenvolvimento , Bifidobacterium/metabolismo , Concentração de Íons de Hidrogênio , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-38696093

RESUMO

Bifidobacteria offer remarkable health benefits when added to probiotic formulations, contributing to the burgeoning market driven by increased awareness among consumers and healthcare providers. However, several pivotal challenges must be crossed: strain selection, encapsulation wall materials, compatible food matrices, and the intricate interplay among these factors. An approach to address these challenges involves exploring bifidogenic substrates as potential encapsulation materials. This strategy has the potential to enhance bifidobacteria viability within the demanding gastrointestinal environment, extend shelf life, and promote synergistic interactions that promote bifidobacteria survival. Nonetheless, it is crucial to acknowledge that the relationship between bifidogenic substrates and bifidobacterial metabolism is complex and multifaceted. Consequently, despite the promising outlook, it is important to emphasize that this approach requires in-depth investigation, as the intricate interplay between these elements constitutes a rich area of ongoing research. This pursuit aims to ultimately deliver consumers a product that can genuinely improve their health and well-being.

11.
Artigo em Inglês | MEDLINE | ID: mdl-37668856

RESUMO

Probiotics, such as Lacticaseibacillus rhamnosus, are essential to the food industry for their health benefits to the host. The Lcb. rhamnosus strain is susceptible to processing, gastrointestinal, and storage conditions. In this study, Lcb. rhamnosus strains were encapsulated by complex coacervation in a gum arabic/chitosan or gum arabic/trehalose/chitosan and cross-linked with sodium tripolyphosphate. The physicochemical properties (zeta potential, water activity, water content, and hygroscopicity), encapsulation efficiency, and probiotic survival under storage conditions and simulated gastrointestinal fluids were evaluated. The results showed that crosslinking improves the encapsulation efficiency after drying; however, this result was remarkable when trehalose was used as a cryoprotectant. Furthermore, the encapsulation matrix preserved the viability of probiotics during 12 weeks with probiotic counts between 8.7-9.5, 7.5-9.0, and 5.2-7.4 log10 CFU g-1 at -20, 4, and 20 °C, respectively. After 12 days of digestion in an ex vivo simulator, acetic, butyric, propionic, and lactic acid production changed significantly, compared to free probiotic samples. This work shows that encapsulation by complex coacervation can promote the stability of probiotic bacteria in storage conditions and improve the viability of Lcb. rhamnosus HN001 during consumption so that they can exert their beneficial action in the organism.

12.
Polymers (Basel) ; 15(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37177348

RESUMO

Chitosan hydrogels are biomaterials with excellent potential for biomedical applications. In this study, chitosan hydrogels were prepared at different concentrations and molecular weights by freeze-drying. The chitosan sponges were physically crosslinked using sodium bicarbonate as a crosslinking agent. The X-ray spectroscopy (XPS and XRD diffraction), equilibrium water content, microstructural morphology (confocal microscopy), rheological properties (temperature sweep test), and cytotoxicity of the chitosan hydrogels (MTT assay) were investigated. XPS analysis confirmed that the chitosan hydrogels obtained were physically crosslinked using sodium bicarbonate. The chitosan samples displayed a semi-crystalline nature and a highly porous structure with mean pore size between 115.7 ± 20.5 and 156.3 ± 21.8 µm. In addition, the chitosan hydrogels exhibited high water absorption, showing equilibrium water content values from 23 to 30 times their mass in PBS buffer and high thermal stability from 5 to 60 °C. Also, chitosan hydrogels were non-cytotoxic, obtaining cell viability values ≥ 100% for the HT29 cells. Thus, physically crosslinked chitosan hydrogels can be great candidates as biomaterials for biomedical applications.

13.
Polymers (Basel) ; 14(5)2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35267677

RESUMO

The work aimed to develop a gel as a protective barrier of common bean protein hydrolysates to be incorporated into a Greek-style yogurt and evaluate the sensory perception and biological potential. The gel was formed by complex coacervation and induced heat at a pH 3.5 and 3:1 biopolymer ratio (whey protein and gum arabic). The gel presented a 39.33% yield, low syneresis (0.37%), and a gel strength of 100 gf. The rheological properties showed an elastic behavior (G' > G″). The gel with the most stable characteristics favored the incorporation of 2.3 g of hydrolysates to be added into the Greek-style yogurt. Nutritionally, the Greek-style yogurt with the encapsulated hydrolysates presented 9.96% protein, 2.27% fat, and 1.76% carbohydrate. Syneresis (4.64%), titratable acidity (1.39%), and viscoelastic behavior presented similar characteristics to the Greek-style control yogurt. The bitterness and astringency in yogurt with encapsulated hydrolysates decreased 44% and 52%, respectively, compared to the yogurt control with the unencapsulated hydrolysates. The Greek-style yogurt with the encapsulated hydrolysates showed the ability to inhibit enzymes related to carbohydrate metabolism (α-amylase (92.47%) and dipeptidyl peptidase-4 (75.24%) after simulated gastrointestinal digestion). The use of gels could be an alternative to transporting, delivering, and masking off-flavors of common bean protein hydrolysates in food matrices to decrease glucose absorption for type 2 diabetes patients.

14.
Nutrients ; 14(3)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35276779

RESUMO

Ionic calcium can help in the prevention of the process of osseous decalcification. This study aimed to evaluate the physicochemical properties and toxic effects of ionic calcium-fiber supplement (ICa+) and its impact on bone health preservation in mice C57/BL6 fed a calcium-deficient diet. Physicochemical properties include FTIR, apparent calcium solubility estimated by the calcium ratio obtained by ionization chromatography and atomic absorption. In vitro genotoxicity and cytotoxicity of the ICa+ were assessed. Twenty-five 7-week-old C57/BL6 mice were fed calcium-free diet (CFD) or CFD plus CaCO3 (1.33 mg Ca) or CFD plus ICa+ (1.33-6.66 mg Ca) for six weeks. After that, bone mass and microstructure parameters were assessed. Histological staining was performed to determine calcium deposits. ICa+ (100%) exhibited an apparent calcium solubility higher than CaCO3 (12.3%). ICa+ showed no cytotoxic and genotoxic in vitro activities. Histomorphometry analysis showed that the ICa+ treated group displayed a higher trabecular number than the trabecular space. Also, the ratio BV/TV was increased compared with all treatments. Ionic calcium-fiber supplementation prevents bone deterioration compared to mice fed a calcium-deficient diet.


Assuntos
Distúrbios do Metabolismo do Cálcio , Cálcio da Dieta , Animais , Densidade Óssea , Cálcio , Cálcio da Dieta/farmacologia , Suplementos Nutricionais , Camundongos
15.
Mater Sci Eng C Mater Biol Appl ; 121: 111806, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33579450

RESUMO

Nowadays it is known that neural cells are capable of regenerating after brain injury, but their success highly depends on the local environment, including the presence of a biological structure to support cell proliferation and restore the lost tissue. Different chitosan-based biomaterials have been employed in response to this necessity. We hypothesized that hydrogels made of antioxidant compounds functionalizing chitosan could provide a suitable environment to home new cells and offer a way to achieve brain repair. In this work, the implantation of functionalized chitosan biomaterials in a brain injury animal model was evaluated. The injury consisted of mechanical damage applied to the cerebral cortex of Wistar rats followed by the implantation of four different chitosan-based biomaterials. After 15 and 30 days, animals underwent magnetic resonance imaging, then they were sacrificed, and the brain tissue was analyzed by immunohistochemistry. The proliferation of microglia and astrocytes increased at the lesion zone, showing differences between the evaluated biomaterials. Also, cell nuclei were seen inside the biomaterials, indicating cell migration and biodegradation. Chitosan-based hydrogels are able to fill in the tissue cavity and bare cells for the endogenous restoration process. The addition of ferulic and succinic acid to the chitosan structure increases this capacity and decreases the inflammatory reaction to the implant.


Assuntos
Lesões Encefálicas , Quitosana , Animais , Materiais Biocompatíveis/farmacologia , Lesões Encefálicas/tratamento farmacológico , Hidrogéis , Ratos , Ratos Wistar , Ácido Succínico
16.
Polymers (Basel) ; 13(12)2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34207947

RESUMO

Chitosan is a natural polymer, and its biological properties depend on factors such as the degree of deacetylation and polymerization, viscosity, molecular mass, and dissociation constant. Chitosan has multiple advantages: it is biodegradable, biocompatible, safe, inexpensive, and non-toxic. Due to these characteristics, it has a wide range of applications. In agriculture, one of the most promising properties of chitosan is as an elicitor in plant defense against pathogenic microorganisms. In this work, four kinds of chitosan (practical grade, low molecular weight, medium molecular weight, and high-density commercial food grade) were used in concentrations of 0.01 and 0.05% to evaluate its protective effect against coffee rust. The best treatment was chosen to evaluate the defense response in coffee plants. The results showed a protective effect using practical-grade and commercial food-grade chitosan. In addition, the activity of enzymes with ß-1,3 glucanase and peroxidase was induced, and an increase in the amount of phenolic compounds was observed in plants treated with high-molecular-weight chitosan at 0.05%; therefore, chitosan can be considered an effective molecule for controlling coffee rust.

17.
J Biomed Mater Res A ; 108(1): 81-93, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31502406

RESUMO

Gelatin/chitosan/polyvinyl alcohol hydrogels were fabricated at different polymer ratios using the freeze-drying and sterilized by steam sterilization. The thermal stability, chemical structure, morphology, surface area, mechanical properties, and biocompatibility of hydrogels were evaluated by simultaneous thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, confocal microscopy, adsorption/desorption of nitrogen, rheometry, and 3-4,[5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide cell viability assay (MTT assay), respectively. The samples showed a decomposition onset temperature below 253.3 ± 4.8°C, a semicrystalline nature, and a highly porous structure. Hydrogels reached the maximum water uptake in phosphate-buffered saline after 80 min, showing values from nine to twelve times their dry mass. Also, hydrogels exhibiting a solid-like behavior ranging from 2,567 ± 467 to 48,705 ± 2,453 Pa at 0.1 rad/s (low frequency). The sterilized hydrogels showed low cytotoxicity (cell viability > 70%) to the HT29-MTX-E12 cell line. Sterilized hydrogels by steam sterilization can be good candidates as scaffolds for tissue engineering applications.


Assuntos
Fenômenos Químicos , Quitosana/química , Quitosana/toxicidade , Hidrogéis/química , Hidrogéis/toxicidade , Esterilização , Varredura Diferencial de Calorimetria , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Elasticidade , Gelatina/química , Células HT29 , Humanos , Nitrogênio/química , Álcool de Polivinil/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Termogravimetria , Viscosidade , Água/química , Difração de Raios X
18.
Carbohydr Polym ; 95(1): 161-6, 2013 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-23618253

RESUMO

The formation of the complex coacervate (CC) phases between gum Arabic (GA) and low molecular weight chitosan (Ch) and the interrelationship between the zeta-potential and viscoelastic properties of the coacervate phase were investigated. The maximum charge difference of biopolymers stock dispersion was displayed in a range of pH between 4.0 and 5.5. Titration experiment between the oppositely charged biopolymers showed that the isoelectric point was found at a biopolymers mass ratio (R[GA:Ch]) of R[5.5:1]. Turbidity, size and ζ-potential of the soluble complexes (SC) showed an interrelation with the complex coacervate yield (CCY). Higher CCY values (82.2-88.1%) were obtained in the range from R[3:1] to R[5.5:1]. Change the R[GA:Ch] in dispersion, make possible to produce CC's phases exhibiting cationic (R[1:1] and R[3:1]), neutral (R[5.5:1]) or anionic (R[9:1] and R[7:1]) charged. All CC's exhibited liquid-viscoelastic behavior at lower frequencies and a crossover between G″ and G' at higher frequencies.


Assuntos
Quitosana/química , Goma Arábica/química , Elasticidade , Concentração de Íons de Hidrogênio , Reologia , Propriedades de Superfície , Viscosidade
19.
Food Sci Nutr ; 1(3): 254-265, 2013 05.
Artigo em Inglês | MEDLINE | ID: mdl-29387355

RESUMO

Ditaxis heterantha is a plant of the Euphorbiaceae family that grows in semiarid regions of Mexico. It produces yellow pigmented seeds that are used for coloring of foods. The seeds contain about 20% of proteins. Proteins of D. heterantha were extracted and fractionated on the basis of solubility. Three main protein fractions were obtained: glutelins, 488 ± 0.5; albumins, 229 ± 2; and total globulins, 160 ± 1 g/kg. The amino acid profile was evaluated for each fraction and protein isolated, where the protein isolate contains essential amino acids such as Val, Phe, Tyr, and Leu. A calorimetric study showed that globulins and glutelins have a high denaturing temperature between 100 and 106°C, while albumins showed a denaturing temperature at 76°C. The protein isolate and its fractions exhibited functional properties: the isolated protein demonstrated good oil-holding capacity of 40.7 g/kg. Foam capacity (FC) and foam stability (FS) were observed principally in glutelins and globulins where FC maximum was 330% and the FS was 28 min. The emulsifying capacity was observed in the same fractions of glutelins and globulins, followed by albumins. However, the glutelin fraction in particular was the only fraction that exhibited emulsifying stability at pH 5, 6, and 7. Gelling capacity was observed in albumins and globulins. This study indicated that protein isolated from D. heterantha could be used in food formulations due to its essential amino acid profile. Glutelin could be used as an emulsifying additive. Additionally, glutelin and globulin were stable at temperatures above 100°C; this is an important factor in food industry, principally in heat processes.

20.
Biomacromolecules ; 8(4): 1313-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17375951

RESUMO

The formation of electrostatic complexes of gum Arabic (GA) with chitosan (Ch), two oppositely charged polysaccharides, as a function of the biopolymers ratio (RGA/Ch), total biopolymers concentration (TBconc), pH, and ionic strength, was investigated. The conditions under which inter-biopolymer complexes form were determined by using turbidimetric and electrophoretic mobility measurements in the equilibrium phase and by quantifying mass in the precipitated phase. Results indicated that optimum coacervate yield was achieved at RGA/Ch = 5, independently of TBconc at the resulting pH of solutions under mixing conditions. High coacervate yields occurred in a pH range from 3.5 to 5.0 for RGA/Ch = 5. Coacervate yield was drastically diminished at pH values below 3.5 due to a low degree of ionization of GA molecules, and at pH values above 5 due to a low solubility of chitosan. Increasing ionic strength decreased coacervate yield due to shielding of ionized groups.


Assuntos
Quitosana/química , Goma Arábica/química , Polímeros/síntese química , Eletroforese , Concentração de Íons de Hidrogênio , Nefelometria e Turbidimetria , Polímeros/química , Cloreto de Sódio/química
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