RESUMEN
Gums are polysaccharides, proteins, and minerals that occur naturally in seed coverings and as exudative resinous substance from woody plants. It is reported to have antibacterial, anticancer, blood sugar regulation, and immune system boosting properties. However, the presence of toxic metals in gum is caused for caution as these metals can be harmful if taken in high quantities. The purpose of this study was to determine the amounts of toxic metals in gums collected from the local market, as many consumers tend to use them daily for incense or food ingredients. Gum samples were extracted from several parts of 10 selected medicinal plants (bark, sap, root, latex, leaf glue, and gum). Two fractions of each sample were produced using nitric acid (NHO3), followed by hydrochloric acid (HCl) at first and then hydrogen peroxide (H2O2). The presence of toxic metals in the solutions was determined using an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP OES). The results showed that most of the elements were detected in high concentrations in Commiphora myrrha (Cd, Cu, Fe, K, Mn, Ni, Pb, and Zn) followed by Benzoin resin (Jawi Oud) and Paeonia officinalis. The most prevalent elements detected in all of the herbal gums were potassium (K) and iron (Fe). Fortunately, the sampled herbal gums were found to be within the WHO/FAO permitted range. This study may provide insights about the safety of the selected gums to be used for food applications. Further in vitro and in vivo toxicity studies should be performed to identify the safe dose.
Asunto(s)
Plantas Medicinales , Plantas Medicinales/química , Metales Pesados/análisis , Espectrofotometría Atómica , Gomas de Plantas/química , Gomas de Plantas/análisisRESUMEN
Legumes are abundant sources of proteins, and white common bean proteins play an important role in air-water interface properties. This study aims to investigate the technical-functional properties of white common bean protein isolate (BPI) as a function of pH, protein concentration, and guar gum (GG) presence. BPI physicochemical properties were analyzed in terms of solubility, zeta potential, and mean particle diameter at pH ranging from 2 to 9, in addition to water-holding capacity (WHC), oil-holding capacity (OHC), and thermogravimetric analysis. Protein dispersions were evaluated in terms of dynamic, interfacial, and foam-forming properties. BPI showed higher solubility (>80 %) at pH 2 and above 7. Zeta potential and mean diameter ranged from 15.43 to -34.08 mV and from 129.55 to 139.90 nm, respectively. BPI exhibited WHC and OHC of 1.37 and 4.97 g/g, respectively. Thermograms indicated decomposition temperature (295.81 °C) and mass loss (64.73 %). Flow curves indicated pseudoplastic behavior, with higher η100 values observed in treatments containing guar gum. The behavior was predominantly viscous (tg δ > 1) at lower frequencies, at all pH levels, shifting to predominantly elastic at higher frequencies. Equilibrium surface tension (γeq) ranged from 43.87 to 41.95 mN.m-1 and did not decrease with increasing protein concentration under all pH conditions. All treatments exhibited Ï < 15°, indicating predominantly elastic surface films. Foaming properties were influenced by higher protein concentration and guar gum addition, and the potential formation of protein-polysaccharide complexes favored the kinetic stability of the system.
Asunto(s)
Galactanos , Mananos , Phaseolus , Gomas de Plantas , Proteínas de Plantas , Solubilidad , Propiedades de Superficie , Gomas de Plantas/química , Galactanos/química , Mananos/química , Concentración de Iones de Hidrógeno , Proteínas de Plantas/química , Phaseolus/química , Tamaño de la Partícula , Agua/químicaRESUMEN
The understanding of cancer immunity and antitumor factors generated by natural polysaccharides is not yet fully comprehended. Polysaccharides, like cashew gum (CG), can exhibit immunomodulatory action and may assist in the antitumor process and side effects relieve. This study aimed to determine the antitumor effect of CG alone or in combination with cyclophosphamide (CTX), and its interactions with immune cells, in a murine melanoma model, using the B16-F10 cell line. Tumor growth inhibition, hematological, histopathological, ELISA, flow cytometry, immunofluorescence, and qRT-PCR analyses were performed to elucidate the antitumor potential, involvement of immune cells, and potential toxic effects. CG showed significant tumor growth inhibition, reaching up to 42.9 % alone and 51.4 % in combination with CTX, with mild toxicity to organs. CG enhanced leukocyte count, even in the presence of CTX. Furthermore, CG influenced the activation of tumor-associated macrophages (TAM), characterized by an increase in Il4, as well as a reduction in Ifng, Il1b, Tgfb, and Il6 gene expression. Nevertheless, these effects did not compromise the antitumor activity of CG. In summary, the combination of CG with CTX is a promising approach for leukopenia, one of the most important side effects of cancer treatment and deserves further investigation.
Asunto(s)
Anacardium , Ciclofosfamida , Melanoma Experimental , Animales , Ciclofosfamida/farmacología , Ratones , Melanoma Experimental/tratamiento farmacológico , Melanoma Experimental/patología , Anacardium/química , Gomas de Plantas/química , Gomas de Plantas/farmacología , Línea Celular Tumoral , Modelos Animales de Enfermedad , Citocinas/metabolismo , Macrófagos Asociados a Tumores/efectos de los fármacos , Macrófagos Asociados a Tumores/inmunologíaRESUMEN
In this study, two nanoemulsions were formulated with essential oil (EO) of Ocimum gratissimum with (EON) or without (EOE) cashew gum (CG). Subsequently, inhibition of melanosis and preservation of the quality of shrimp stored for 16 days at 4 ± 0.5 °C were evaluated. A computational approach was performed to predict the system interactions. Dynamic light scattering (DLS) and atomic force microscopy (AFM) were used for nanoparticle analysis. Gas chromatography and flame ionization detector (GC-FID) determined the chemical composition of the EO constituents. Shrimps were evaluated according to melanosis's appearance, psychrotrophic bacteria's count, pH, total volatile basic nitrogen, and thiobarbituric acid reactive substances. EON exhibited a particle size three times smaller than EOE. The shrimp treated with EON showed a more pronounced sensory inhibition of melanosis, which was considered mild by the 16th day. Meanwhile, in the other groups, melanosis was moderate (EOE) or severe (untreated group). Both EON and EOE treatments exhibited inhibition of psychrotrophic bacteria and demonstrated the potential to prevent lipid oxidation, thus extending the shelf life compared to untreated fresh shrimp. EON with cashew gum, seems more promising due to its physicochemical characteristics and superior sensory performance in inhibiting melanosis during shrimp preservation.
Asunto(s)
Anacardium , Ocimum , Aceites Volátiles , Animales , Aceites Volátiles/farmacología , Aceites Volátiles/química , Ocimum/química , Anacardium/química , Penaeidae/química , Gomas de Plantas/química , Conservación de Alimentos/métodosRESUMEN
The development of cosmetic formulations with moisturizing and film-forming properties has been very important to help keep skin physiology and protection. In this context, this study aimed to develop a cosmetic formulation containing Tara gum and Brazilian berry extract and evaluate its physical-mechanical, film-forming, and sensory properties. A gel formulation was developed based on Tara gum added to Plinia cauliflora extract and was characterized by its spreadability profile and sensory properties. A clinical study was carried out with ten participants to evaluate the skin microrelief, stratum corneum water content, transepidermal water loss (TEWL), and skin morphological characteristics by reflectance confocal microscopy (RCM) before and after 2 h of application of the formulations. The formulation with Brazilian berry significantly decreased the work of shear parameter, which can be correlated with improved spreadability in the sensory analysis. The clinical study showed that both formulations improved skin hydration and reduced the TEWL. The RCM imaging analysis showed the visible film on the skin surface, a decrease in the size of furrows, an increase in the reflectance of the interkeratinocytes, and reflectance of the stratum corneum for both formulations. These results were more pronounced for the formulation containing Brazilian berry. The Tara gum in the gel formulation promoted the formation and visualization of a polymeric net on the stratum corneum surface, demonstrated by the images obtained from RCM. However, the formulation added with the Brazilian berry extract improved the skin microrelief, honeycomb pattern of the epidermis, and skin hydration in deeper layers of the epidermis.
Asunto(s)
Cosméticos , Frutas , Gomas de Plantas , Humanos , Brasil , Epidermis/fisiología , Piel , AguaRESUMEN
Hydrogels from natural sources are attracting increasing interest due to their ability to protect biologically active molecules. Starch extracted from cassava tubers is a promising material for synthesizing these hydrogels. Copolymerization of cassava gum and incorporation of chlorhexidine digluconate (CLX) into the hydrogels is confirmed by changes in the crystallographic profile, as observed through X-ray diffraction, and a shift in the 1000 cm-1 band in the Fourier-transform infrared spectroscopy spectrum. The differential scanning calorimetry reveals changes in the decomposition temperature of the synthesized hydrogels related to CLX volatility. Micrographs illustrate the material's porosity. Release tests indicate a constant linear release over 72 h, while antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans is satisfactory, with 100% effectiveness from 0.5% CLX and the formation of inhibition halos. Toxicity and biocompatibility studies show no cytotoxicity. The continuous release of chlorhexidine is promising for components of biomedical implants and applications as it can ensure antimicrobial action according to specific therapeutic needs.
Asunto(s)
Antiinfecciosos , Candida albicans , Clorhexidina , Escherichia coli , Hidrogeles , Manihot , Staphylococcus aureus , Clorhexidina/farmacología , Clorhexidina/química , Clorhexidina/análogos & derivados , Manihot/química , Hidrogeles/química , Hidrogeles/farmacología , Hidrogeles/síntesis química , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Antiinfecciosos/farmacología , Antiinfecciosos/química , Antiinfecciosos/síntesis química , Gomas de Plantas/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Pruebas de Sensibilidad Microbiana , Liberación de FármacosRESUMEN
Polysaccharides in plant-exuded gums are complex biopolymers consisting of a wide range of structural variability (linkages, monosaccharide composition, substituents, conformation, chain length and branching). The structural features of polysaccharides confer the ability to be exploited in different industrial sectors and applications involving biological systems. Moreover, these characteristics are attributed to a direct relationship in the process of polysaccharide enzymatic degradation by the fermentative action in the gut microbiota, through intrinsic interactions connecting bacterial metabolism and the production of various metabolites that are associated with regulatory effects on the host homeostasis system. Molecular docking analysis between bacterial target proteins and arabinogalactan-type polysaccharide obtained from gum arabic allowed the identification of intermolecular interactions provided bacterial enzymatic mechanism for the degradation of several arabinogalactan monosaccharide chains, as a model for the study and prediction of potential fermentable polysaccharide. This review discusses the main structural characteristics of polysaccharides from exudate gums of plants and their interactions with the intestinal microbiota.
Asunto(s)
Microbioma Gastrointestinal , Prebióticos , Simulación del Acoplamiento Molecular , Polisacáridos/química , Gomas de Plantas/química , Plantas/metabolismo , MonosacáridosRESUMEN
The aim of the present work was to modify the exuded gum of Sterculia striata tree by an amination reaction. The viscosity and zero potential of the chicha gum varied as a function of pH. The modification was confirmed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), size exclusion chromatography (SEC), zeta potential, thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Furthermore, the chemical modification changed the molar mass and surface charge of the chicha gum. In addition, the gums were used in tests for ex vivo mucoadhesion strength, antibacterial activity against the standard strain of Staphylococcus aureus (ATCC 25923), inhibitory activity of α-glucosidase, antioxidant capacity, and viability of Caco-2 cells. Through these tests, it was found that amination caused an increase in the mucoadhesive and inhibitory activity of chicha gum against the bacterium Staphylococcus aureus. In addition, the gums (pure and modified) showed antioxidant capacity and an inhibitory effect against the α-glucosidase enzyme and did not show cytotoxic potential.
Asunto(s)
Antioxidantes , alfa-Glucosidasas , Humanos , Antioxidantes/farmacología , Células CACO-2 , Antibacterianos/farmacología , Antibacterianos/química , Difracción de Rayos X , Gomas de Plantas/farmacología , Gomas de Plantas/química , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Natural gums are a source of biopolymeric materials with a wide range of applications for multiple purposes. These polysaccharides are extensively explored due to their low toxicity, gelling and thickening properties, and bioadhesive potential, which have sparked interest in researchers given their use in producing pharmaceutic dosage forms compared to synthetic agents. Hence, gums can be used as gelling and film-forming agents, which are suitable platforms for topical drug administration. Additionally, recent studies have demonstrated the possibility of obtaining nanocomposite materials formed by a polymeric matrix of gums associated with nanoscale carriers that have shown superior drug delivery performance and compatibility with multiple administration routes compared to starting components. In this sense, research on topical natural gum-based form preparation containing drug-loaded nanocarriers was detailed and discussed herein. A special focus was devoted to the advantages achieved regarding physicochemical and mechanical features, drug delivery capacity, permeability through topical barriers, and biocompatibility of the hydrogels and polymeric films.
Asunto(s)
Hidrogeles , Gomas de Plantas , Sistemas de Liberación de Medicamentos , Gomas de Plantas/química , Polisacáridos/químicaRESUMEN
OBJECTIVES: Dietary fibers, such as fructooligosaccharide (FOS) and partially hydrolyzed guar gum (PHGG) have several gastrointestinal functions. The aims of this study were to evaluate the effect of acute ingestion of FOS and PHGG on the percentage of gastric emptying and small intestinal transit and to evaluate the effect of these dietary fibers on the levels of intestinal hormones-active glucagon-like peptide-1, pancreatic polypeptide, and gastric inhibitory peptide-and their effect on feelings of hunger and satiety and the desire to eat. METHODS: In this crossover, randomized controlled clinical trial, we compared the effects of these two fibers on gastrointestinal transit. The tests were performed using scintigraphy. On three different days, healthy participants consumed a test meal containing 20 g of digestible maltodextrin (placebo), 20 g of FOS, or 20 g of PHGG. RESULTS: The gastric emptying of the FOS-based diet (84.2 ± 9.4%) within 2 h was statistically increased compared with the placebo and PHGG-based diets (78 ± 10.2% and 74 ± 15.3%, respectively; P < 0.05). However, a reduction in small intestinal transit was observed after consumption of both FOS- and PHGG-based diets (28.5 ± 15.56% and 24.2 ± 13.7%, respectively) compared with the placebo diet (41.20 ± 15.4%; P < 0.05). There were no changes in the levels of intestinal hormones, feeling of hunger and satiety, or desire to eat after consuming the three diets (P > 0.05). CONCLUSION: The acute intake of FOS increased gastric emptying, whereas both FOS and PHGG reduced small intestine transit without altering the levels of intestinal hormones, hunger feelings and satiety, or the desire to eat.
Asunto(s)
Hormonas Gastrointestinales , Tránsito Gastrointestinal , Fibras de la Dieta/farmacología , Galactanos , Hormonas Gastrointestinales/farmacología , Humanos , Mananos/farmacología , Oligosacáridos , Gomas de PlantasRESUMEN
In this work, we describe the synthesis, the characterization, and the potential application of a pH-responsive guar gum-based hydrogel. The polysaccharide produced permanent hydrogels with improved biocompatibility. In this work, we report the chemical modification of guar gum (with glycidyl methacrylate) and its use, as the main constituent, in obtaining chemically cross-linked hydrogels. The morphology, swelling properties, and cytotoxicity of the resulting materials were studied in-depth. The hydrogels showed to be pH-responsive, and non-toxic being safe to use it as a biomaterial. In addition, we tested the potential of this one as a drug carrier. Herein, we have chosen hydrocortisone (HCS) as a drug model. The mechanism of HCS release changed as a function of pH, owing to different responses in each medium. Our results indicate that the guar gum hydrogels have great potential to be used, with safety, as a drug carrier.
Asunto(s)
Hidrocortisona , Hidrogeles , Galactanos/química , Hidrogeles/química , Concentración de Iones de Hidrógeno , Mananos , Gomas de Plantas/química , AguaRESUMEN
BACKGROUND: Tara gum (TG) is characterized by its high viscosity and medium solubility, which is a result of its high molecular mass. However, for many applications, these characteristics are undesirable, making the use of TG infeasible. The present study aimed to evaluate the effect of high-intensity ultrasound on the depolymerization of aqueous solutions of TG. The effect of ultrasonication was investigated by viscometry analysis as well as Fourier transform infrared spectroscopy (FTIR) and solubility. RESULTS: The intrinsic viscosity (η) and the molecular weight (Mw ) of TG decreased after ultrasound, achieving a molecular weight reduction of 13.50 × 105 g mol-1 after 60 min of sonication at 25 °C compared to 22.04 × 105 g mol-1 before treatment. Degradation kinetics were applied to estimate the rate constant of degradation (k). It was found that the k value of TG increased with increasing temperature from 25 to 55 °C. Partially hydrolyzed TG showed greater solubility at the two temperatures investigated (25 and 80 °C). Ultrasonic treatment did not change the chemical structure of the TG molecules according to the structural analysis by FTIR, confirming its action only as breaking the structure of the polymer. CONCLUSION: Ultrasound is a simple method for effectively reducing the molecular weight and viscosity and increasing the solubility of TG without using chemical reagents. The synthesis of partially hydrolyzed TG expands its potential for use in food products, including as a soluble dietary fiber. © 2022 Society of Chemical Industry.
Asunto(s)
Gomas de Plantas , Ultrasonido , Gomas de Plantas/química , Temperatura , Viscosidad , Agua/químicaRESUMEN
This study evaluated the viability of using soy gum (residue from soy processing to obtain degummed oil) as an emulsifier in starter diets for broilers (1 to 21 days). For this, 600 1-day-old male broilers (Cobb® 500) were randomly assigned in a factorial arrangement (3 x 4), with three levels of gum inclusion (0, 1.25, and 2.5%) and four levels of soybean oil (0,1.3, 2.6, and 3.9%), with 5 replicates of 10 birds each. At 7, 14, and 21 days of age, we analyzed the performance parameters, pancreatic lipase activity and digestibility coefficients. Inclusion of soy gum improved (p<0.05) the performance and the digestibility coefficient of the ether extract, increased (p<0.05) the levels of AME and AMEn. The higher inclusion of gum (2.5%) as an emulsifier resulted in improved performance, showing the best values of feed conversion, with increased ether extract digestibility, increased AME content of the diets, and a lower requirement for pancreatic lipase in micelle formation.(AU)
Asunto(s)
Animales , Pollos/fisiología , Emulsionantes/análisis , Gomas de Plantas/efectos adversos , Glycine max/químicaRESUMEN
Trees of the genus Sterculia produce polysaccharide-rich exudates, such as karaya gum (Sterculia urens), chicha gum (Sterculia striata), and Sterculia foetida gum. These anionic biomaterials are biodegradable, with high viscosity, low toxicity, and gelling properties in aqueous media. According to these properties, they show promising applications as a polymer matrix for use in drug delivery systems. For this application, both the chemically modified and the unmodified polysaccharide are used. This review focuses on analyzing the state of the art of recent studies on the use of Sterculia gums in a variety of pharmaceutical forms, such as tablets, hydrogels, micro/nanoparticles, and mucoadhesive films. Sterculia gums-based delivery systems have potential to be explored for new drug delivery systems.
Asunto(s)
Materiales Biocompatibles/química , Sistemas de Liberación de Medicamentos , Gomas de Plantas/química , Sterculia/metabolismo , Liberación de FármacosRESUMEN
In this study, nanoemulsions of essential oil from Ocimumgratissimum (Linn) (EO) were produced using low and high energy techniques using cashew gum (CG) as a co-surfactant. The main constituents of the EO were determined by Gas Chromatography coupled with Mass Spectrometry (GC-MS), and their presence in the EO and in the formulations verified by Fourier Transform Infrared Spectroscopy (FTIR) and UV-visible spectrophotometry was observed the encapsulation efficiency (EE%), with colloidal stability. Nuclear magnetic resonance (NMR) was used to study cashew gum. Dynamic light scattering analysis (DLS) determined the nanoemulsion Z means, polydispersity index and the Zeta potential value, nanoparticle tracking analysis (NTA) were determined. The nanostructured EO showed better antibacterial action against the pathogenic gastroenteritis species Staphylococcus aureus, Escherichia coli and Salmonella enterica when compared to free EO. Atomic Force Microscopy (AFM) was used for morphological analysis of the nanoparticle and study of the action of the nanoemulsion through images of the cellular morphology of S. enterica. The antioxidant activity was evaluated against the ABTS radical (2,2'-azino-bis diazonium salt (3-ethylbenzothiazoline-6-sulfonic acid)). The encapsulation of EO in a nanostructured system improved its antibacterial and antioxidant activity, the low energy synthesis showed greater storage stability, remaining stable for 37 days.
Asunto(s)
Antibacterianos/química , Emulsiones/química , Ocimum/metabolismo , Aceites Volátiles/química , Gomas de Plantas/química , Hojas de la Planta/metabolismoRESUMEN
Industrial application of lycopene is limited due to its chemical instability and low bioavailability. This study proposes the development of fucan-coated acetylated cashew gum nanoparticles (NFGa) and acetylated cashew gum nanoparticles (NGa) for incorporation of the lycopene-rich extract from red guava (LEG). Size, polydispersity, zeta potential, nanoparticles concentration, encapsulation efficiency, transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to characterize nanoparticles. The antioxidant activity was determinated and cell viability was evaluated in the human breast cancer cells (MCF-7) and human keratinocytes (HaCaT) by MTT assay. The toxic effect was evaluated by hemolysis test and by Galleria mellonella model. NFGa showed higher stability than NGa, having a size of 162.10 ± 3.21 nm, polydispersity of 0.348 ± 0.019, zeta potential -30.70 ± 0.53 mV, concentration of 6.4 × 109 nanoparticles/mL and 60% LEG encapsulation. Microscopic analysis revealed a spherical and smooth shape of NFGa. NFGa showed antioxidant capacity by ABTS method and ORAC assay. The NFGa presented significant cytotoxicity against MCF-7 from the lowest concentration tested (6.25-200 µg/mL) and did not affect the cell viability of the HaCaT. NFGa showed non-toxic effect in the in vitro and in vivo models. Therefore, NFGa may have a promising application in LEG stabilization for antioxidant and antitumor purposes.
Asunto(s)
Anacardium/química , Antineoplásicos/administración & dosificación , Antioxidantes/administración & dosificación , Licopeno/administración & dosificación , Nanopartículas/química , Gomas de Plantas/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Células HaCaT , Humanos , Licopeno/química , Licopeno/farmacología , Células MCF-7 , Polisacáridos/química , Psidium/química , OvinosRESUMEN
We developed a new hydrophobic polymer based on angico gum (AG), and we produced new nanoparticles to expand the applications of natural polysaccharides in nanomedicine. Phthalate angico gum (PAG) was characterized by 1H NMR, FTIR, elementary analysis, solubility, XRD, and TG. PAG was a hydrophobic and semi-crystalline material, a relevant characteristic for drug delivery system applications. As a proof of concept, nevirapine (NVP) was selected for nanoparticles development. Plackett-Burman's experimental design was used to understand the influence of several factors in nanoparticles production. PAG proved to be a versatile material for producing nanoparticles with different characteristics. Optimized nanoparticles were produced using desirability parameters. NVP-loaded PAG nanoparticles formulation showed 202.1 nm of particle size, 0.23 of PDI, -17.1 of zeta potential, 69.8 of encapsulation efficiency, and promoted modified drug release for 8 h. Here we show that PAG presents as a promising biopolymer for drug delivery systems.
Asunto(s)
Tecnología Química Verde , Nanopartículas/química , Nanotecnología , Ácidos Ftálicos/química , Gomas de Plantas/química , Liberación de Fármacos , Humanos , Microscopía de Fuerza Atómica , Peso Molecular , Nevirapina/farmacología , Tamaño de la Partícula , Espectroscopía de Protones por Resonancia Magnética , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Difracción de Rayos XRESUMEN
This research reports, for the first time, the immobilization of an enzyme - Rhus vernificera laccase - on cashew gum (CG) nanoparticles (NPs) and its application as a biological layer in the design and development of an electrochemical biosensor. Laccase-CG nanoparticles (LacCG-NPs) were prepared by the nanoprecipitation method and characterized by UV-Vis spectrophotometry, atomic force microscopy, scanning electron microscopy, attenuated total reflectance-Fourier-transform infrared spectroscopy, circular dichroism, cyclic voltammetry, and electrochemical impedance spectroscopy. The average size and stability of the NPs were predicted by DLS and zeta potential. The ATR-FTIR results clearly demonstrated an interaction between -NH and -OH groups to form LacCG-NPs. The average size found for LacCG-NPs was 280 ± 53 nm and a polydispersity index of 0.309 ± 0.08 indicated a good particle size distribution. The zeta potential shows a good colloidal stability. The use of a natural product to prepare the enzymatic nanoparticles, its easy synthesis and the immobilization efficiency should be highlighted. LacCG-NPs were successfully applied as a biolayer in the development of an amperometric biosensor for catechol detection. The resulting device showed a low response time (6 s), good sensitivity (7.86 µA µM-1 cm-2), wide linear range of 2.5 × 10-7-2.0 × 10-4 M, and low detection limit (50 nM).
Asunto(s)
Materiales Biocompatibles/química , Técnicas Biosensibles , Catecoles/análisis , Lacasa/química , Nanopartículas/química , Gomas de Plantas/química , Anacardium/química , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/metabolismo , Conformación de Carbohidratos , Técnicas Electroquímicas , Lacasa/metabolismo , Ensayo de Materiales , Modelos Moleculares , Nanopartículas/metabolismo , Tamaño de la Partícula , Gomas de Plantas/aislamiento & purificación , Gomas de Plantas/metabolismo , Toxicodendron/enzimologíaRESUMEN
The beneficial effects of a healthy diet on the quality of life have prompted the food industry to develop low-fat variants, but fat content directly affects the physicochemical and sensory properties of food products. The utilization of high-pressure homogenization (HP) and incorporation of hydrocolloids have been suggested as strategies to improve the physical stability and rheological properties of light cream. Thus, this study aims to analyze the associated effect of high-pressure homogenization (80 MPa) and three different hydrocolloids: microcrystalline cellulose, locust bean gum and xanthan gum, on emulsion stability and rheological properties of ultra-high-temperature (UHT) light cream (ULC) with a 15% w/w fat content. The stability of ULC was determined by the ζ potential of oil droplets and emulsion stability percentage. Rheological characterization was based on flow behavior tests and dynamic oscillatory measurements, which were carried out in a rheometer. Results showed that the high-pressure homogenization process did not influence the emulsion stability of the treatments. Moreover, the hydrocolloids added to systems present weak interactions with milk proteins since all ULC showed macroscopical phase separation. The samples presented the same rheological behavior and were classified as pseudoplastic fluids (n < 1). ULC treated at 80 MPa was significantly (P ≤ 0.05) more consistent than the treatments at 20 MPa. All ULC showed a predominant elastic behavior (G' > Gâ³), and a remarkable increase in both G' and Gâ³ at 80 MPa. The results presented in this study highlight the potential of HP for altering some rheological characteristics of UHT light cream, for example, to increase its consistency. These results are important for the dairy industry and ingredient suppliers, in the standardization of UHT light cream and/or to develop low-fat products.
Asunto(s)
Coloides/administración & dosificación , Productos Lácteos , Grasas de la Dieta/análisis , Manipulación de Alimentos/métodos , Calor , Leche/química , Animales , Celulosa , Fenómenos Químicos , Dieta con Restricción de Grasas , Emulsiones , Galactanos , Mananos , Gomas de Plantas , Polisacáridos Bacterianos , Presión , ReologíaRESUMEN
Agricultural production is influenced by the water content in the soil and availability of fertilizers. Thus, superabsorbent hydrogels, based on polyacrylamide, natural cashew tree gum (CG) and potassium hydrogen phosphate (PHP), as fertilizer and water releaser were developed. The structure, morphology, thermal stability and chemical composition of samples of polyacrylamide and cashew tree gum hydrogels with the presence of fertilizer (HCGP) and without fertilizer (HCG) were investigated, using X-ray diffractometry (XRD), Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA/DTG) and Energy Dispersive Spectroscopy (EDS). Swelling/reswelling tests, textural analysis, effect of pH, release of nutrients and kinetics were determined; the ecotoxicity of the hydrogels was investigated by the Artemia salina test. The results showed that PHP incorporation in the hydrogel favored the crosslinking of chains. This increased the thermal stability in HCGP but decreased the hardness and adhesion properties. The HCGP demonstrated good swelling capacity (~15,000 times) and an excellent potential for reuse after fifty-five consecutive cycles. The swelling was favored in an alkaline pH due to the ionization of hydrophilic groups. The sustained release of phosphorus in HCGP was described by the Korsmeyer-Peppas model, and Fickian diffusion is the main fertilizer release mechanism. Finally, the hydrogels do not demonstrate toxicity, and HCGP has potential for application in agriculture.