Antifungal edible coatings for fruits based on zein and chitosan nanowhiskers.

Fresh produce have a more limited shelf life than processed ones. Their sensory attributes such as appearance and surface texture are important features in consumer perception and liking. The decomposition of fresh produce, which is caused by enzymes, chemical reactions, and microbial infections, often caused by Colletotrichum species, is inevitable. However, it can be slowed down. Several materials have been developed for this purpose, with an emphasis on active coatings using nanomaterials. In this study, the protective effects of a zein coating containing chitosan nanowhiskers (CSW) for the maintenance of fruit quality were investigated using guava (Psidium guajava L.) as a model fruit. CSW were previously characterized, and their antifungal effects against distinct Colletotrichum species (Colletotrichum asianum, Colletotrichum tropicale, Colletotrichum gloeosporioides, and Colletotrichum brevisporum) were proven. Coatings were characterized by thermogravimetric analysis, optical profilometry, and mechanical properties. Total soluble solids, pH, mass loss, and visual inspection of uncoated and coated guava fruits were also verified during 9 days. Results show that CSW length and aspect ratio decreased for longer extraction times. A similar behavior was found for x-ray diffraction in which peak intensity decreases under the same conditions. CSW degradation (ca. 250-400°C) also depends on extraction time in which more crystalline whiskers are the most thermally stable ones. The addition of CSW did not significantly (p < 0.05) modify the homogeneity and continuity of coating but prevented microbial growth assuring fruit quality during storage. In summary, coatings protected guava fruits from post-harvest spoilage while preserving quality and extending shelf life. PRACTICAL APPLICATION: Fresh foods such as fruits and vegetables have a more limited shelf life than processed ones.

Palm density and grazing effects on plant communities: implications for livestock management in a Butia palm grove.

Some grasslands in ecotones with forests tend to be encroached by woody species, because of changes in climate and land use. Such structural changes in vegetation can be facilitated when the grassland community presents an autochthonous arboreal component, like Butia palms. We aim to identify the responses of taxonomic and functional diversity on grassland community with the occurrence of arborescent/arboreal species (autochthonous and encroaching) to palm density and grazing intensity. The study was conducted in a Butia odorata palm grove under cattle management, in Southern Brazil. To assess the taxonomic and functional composition we performed ordinations analysis with the vegetational data and using path analysis we assessed the causal relationships between variables of interest. Density of Butia odorata and woody plants were strongly positive related, suggesting a facilitation process in the establishment of arborescent plants on the grassland matrix. The abundance of less palatable plants and grazing pressure were inversely related, indicating a selection process induced by higher grazing intensity. We suggest that the grazing intensity management must be based on the autochthonous tree density, applying higher grazing intensity in areas with higher density of encroaching plants, in addition to maintaining other regions conducive to Butia palm regeneration through fallows.

Cardanol-based adhesive with reduced formaldehyde emission to produce particleboards with waste from bean crops.

Free formaldehyde is a carcinogen whose emission reduction in particleboard has been studied recently to mitigate this environmental and human health problem. One alternative to reduce the emission of formaldehyde in particleboards is by using adhesives produced from natural sources. Cardanol-formaldehyde is an environmentally friendly adhesive made with cashew nut liquid, a byproduct from the cashew chain. This work aimed to produce particleboard using cardanol-formaldehyde in place of urea. In addition, different proportions of bean straw wastes were used to replace pine wood. The combination of eco-friendly adhesive and lignocellulosic waste particles could result in a product that meets market demands while being environmentally nonaggressive. Cardanol-formaldehyde promoted a higher modulus of elasticity (MOE) (1172 MPa) and modulus of rupture (MOR) (4.39 MPa) about panels glued with urea-formaldehyde, which presented a MOE of 764 MPa and MOR of 2.45 MPa. Furthermore, the cardanol-formaldehyde adhesive promoted a 93% reduction in formaldehyde emission, with a reduction from 16.76 to 1.09 mg/100 g oven-dry board for particleboards produced with cardanol-formaldehyde, indicating potential as an adhesive in the particleboard industry.

Estimating hydroxyl/epoxy ratio in graphene oxide through adsorption experiment and semiempirical GFN2-xTB quantum method.

CONTEXT: The reactivity of graphene oxide (GO) with amines is related to the ring-opening of the epoxy groups in its basal surface, as addressed experimentally. Therefore, discussing the hydroxyl/epoxy ratio for GO is relevant to improve the characterization of such material. As the adsorption of Methylene Blue into GO is related to a graphene derivative's oxidation degree (OD), we combined adsorption experimental information and theoretical data to estimate the hydroxyl/epoxy ratio. The theoretical data were compared to the experimental adsorption of Methylene Blue and Indigo Carmine into GO synthesized in our department. Our results show GO systems with hydroxyl/epoxy ratios equal to 0.7, 0.8, and 0.9 are the most representative in which the most coherent model corresponds to OH/EP=0.8 for our GO previously synthesized. METHODS: The GO-MODEL software was developed in the present work to obtain cartesian coordinates of GO systems. We investigated 204 systems comprising models with 486 carbon atoms with the GFN2-xTB semiempirical quantum method. The supramolecular arrangements were constructed with the recently developed UD-APARM program.

Ghost Fat: Altered Female Body Perception After Bariatric Surgery.

Body perception is an individual's ability to recognize their body in attitudinal and/or dimensional aspects. We investigated women's body perceptions before and after bariatric surgery. Participants were 31 women (M age = 36.23, SD = 7.95 years old) with an average pre-operative body mass index of 44.58 (SD = 4.65) kg/m2. We collected anthropometric and body perception measures (attitudinal body image [ABI] and dimensional body image [DBI]) before bariatric surgery and 30, 60, 90, and 120 days after it. There was an average decrease of 21.09% in participants' body weight over the 120 days. Regarding ABI, 51.61% of participants had high body dissatisfaction before surgery, and this proportion of dissatisfied participants decreased to 3.23% 120 days after surgery. We observed no statistically significant differences in DBI perceptions. Fast weight loss caused by bariatric surgery appeared to generate a perception of ghost fat. Somatosensory interventions and/or a longer follow-up are needed to alter this persistent distortion of body dimensions.

In vitro and in vivo efficacy of poly(lactic acid) nanofiber packaging containing essential oils from Ocimum basilicum L. and Ocimum gratissimum L. against Aspergillus carbonarius and Aspergillus niger in table grapes.

Apergillus carbonarius and Aspergillus niger are the principal fungi that attack table grapes, and they are responsible for producing and contaminating these fruits with ochratoxin A. Packaging containing essential oils from Ocimum gratissimum L. and Ocimum basilicum L. encapsulated in poly(lactic acid) (PLA) nanofibers were produced, the antifungal and antiocratoxigenic activities against A. carbonarius and A. niger were evaluated in vitro and in vivo, and the effect of these packages on the quality of table grapes was determined. The nanofibers were produced by the Solution Blow Spinning technique and characterized by Scanning Electron Microscopy and Thermogravimetric Analysis. Fungal contamination and ochratoxin A production were significantly controlled by PLA nanofibers containing the essential oils and the physicochemical parameters of the grapes were preserved, preserving the quality and the shelf life of the fruit. Therefore, the active packaging developed herein has potential and may be suitable for application in fruits.

Active packaging of poly(lactic acid) nanofibers and essential oils with antifungal action on table grapes.

The table grape is a non-climateric fruit that is very susceptible to fungal contamination, in addition to suffering an accelerated loss of quality during storage. The in vitro and in grape antifungal and antiocratoxigenic effects of the essential oils from Alpinia speciosa and Cymbopogon flexuosus against Aspergillus carbonarius and Aspergillus niger were studied. The oils were encapsulated in poly(lactic acid) (PLA) nanofibers as a potential active packaging to be applied to control the degradation of grapes stored during the post-harvest period. Fungal proliferation and ochratoxin A synthesis in A. carbonarius and A. niger decreased in the presence of the active packaging. However, the nanofiber containing the essential oil from C. flexuosus was more efficient in providing a fungicidal effect against A. carbonarius (10% and 20%) and A. niger (20%). In addition, weight loss and color changes were controlled and the parameters of acidity, °Brix, softening and the texture of the grape were maintained. A very small mass loss of the essential oils encapsulated in nanofibers was observed by thermogravimetric analysis, showing that the nanofiber was efficient in enabling the controlled release. The quality and safety of table grapes were maintained for longer periods of storage in the presence of active packaging, so the incorporation of these oils in nanofibers can be a promising way to increase the shelf life of grapes.

Controlled release and antiviral activity of acyclovir-loaded PLA/PEG nanofibers produced by solution blow spinning.

Herpetic dermatitis and oral recurrent herpes (ORH) are among the most common human infections. Antiviral drugs such as acyclovir (ACV) are used in the standard treatment for ORH. Despite its therapeutic efficacy, ACV is continuously and repetitively administered in high doses. In this sense, the development of controlled release drug delivery systems such as core-shell fibers have a great potential in the treatment of ORH. In this work, poly(lactic acid)/poly(ethylene glycol) (PLA/PEG) fibers were produced by solution blow spinning (SBS) for the controlled release of ACV encapsulated in the core. PLA/PEG nanofibers containing four different blend ratios (100:0, 90:10, 80:20 and 70:30 wt%) without or with 10 wt% ACV were characterized by scanning electron microscopy (SEM), thermogravimetry (TG) and differential scanning calorimetry (DSC). The ACV release profile for 21 days was accessed by UV-Vis spectroscopy. Static water contact angles of the spun fiber mats were measured by the sessile drop method to evaluate fiber wettability upon contact with skin for transdermal release. Cytotoxicity and antiviral efficacy against Herpes simplex viruses (HSV-1) were evaluated using Vero cells. ACV addition did not impact on morphology, but slightly improved thermal stability of the fibers. Addition of hydrophilic PEG in PLA/PEG blends, however, increased drug release as confirmed by contact angle measurements and release profile. The in vitro tests showed the effectiveness of the drug delivery systems developed in reducing HSV-1 viral titer, which is related to the judicious combination of polymers used in the fibrous mats, in addition to not being cytotoxic to Vero cells. These results show the great potential of PLA/PEG solution blow-spun fibers in the controlled release of ACV to develop practical devices for the treatment of cold sores, while favoring the aesthetic appearance by covering them with a soft tissue patch (fibrous mats).

Antifungal and physicochemical properties of Ocimum essential oil loaded in poly(lactic acid) nanofibers.

Poly(lactic acid) (PLA) nanofibres containing different proportions of the essential oils from Ocimum basilicum L. and Ocimum gratissimum L. were prepared by solution blow spinning method. The essential oils were extracted by hydrodistillation and characterized by gas chromatography. MEV, contact angle, DSC and FTIR were used to characterize the nanofibres. The effect of bioative nanofibres on the growth of the fungus and on the production of ochratoxin A were evaluated using the fumigation test. Linalool, 1·8-cineole and camphor were the principal components of the essential oil from O. basilicum, and eugenol was the principal constituent in the oil from O. gratissimum. An increase in the average diameter of the nanofibres was observed with the addition of the essential oils. The essential oils acted as a plasticizer, resulting in a reduction in the crystallinity of the PLA. The encapsulation of essential oils in PLA nanofibres was verified by FTIR. An effective antifungal and antimicotoxygenic activity against Aspergillus ochraceus and Aspergillus westerdjikiae was observed for the bioative nanofibres. These results confirm the potential of PLA nanofibres containing the essential oils for the control of toxigenic fungi that cause the deterioration of food and are harmful to human health.

Multiple Reflections for Classical Particles Moving under the Influence of a Time-Dependent Potential Well.

We study the dynamics of classical particles confined in a time-dependent potential well. The dynamics of each particle is described by a two-dimensional nonlinear discrete mapping for the variables energy en and phase ϕn of the periodic moving well. We obtain the phase space and show that it contains periodic islands, chaotic sea, and invariant spanning curves. We find the elliptic and hyperbolic fixed points and discuss a numerical method to obtain them. We study the dispersion of the initial conditions after a single iteration. This study allows finding regions where multiple reflections occur. Multiple reflections happen when a particle does not have enough energy to exit the potential well and is trapped inside it, suffering several reflections until it has enough energy to exit. We also show deformations in regions with multiple reflection, but the area remains constant when we change the control parameter NC. Finally, we show some structures that appear in the e0e1 plane by using density plots.

Development of quaternary nanocomposites made up of cassava starch, cocoa butter, lemongrass essential oil nanoemulsion, and brewery spent grain fibers.

We report on production of novel quaternary nanocomposite films based on thermoplastic starch (TPS, 8% w/v) derived from cassava, cocoa butter, (CB, 30% wt.%), and lemongrass essential oil (LEO, 1:1) nanoemulsions reinforced with different concentrations of brewery spent grain (BSG, 5 or 10 wt.%) fibers, by continuous casting. The chemical composition, the morphological, thermal, mechanical properties, film barrier, biodegradability in the vegetable compound, in addition to the application in chocolates, have been widely studied. The addition of CB, LEO, and BSG caused relevant changes in the starch-based films, such as increased extensibility (from 2.4-BSG5 to 9.4%-BSG10) and improved barrier to moisture (2.9 and 2.4 g.mm.kPa-1 .h-1 .m-2 ). Contrastingly, the thermal stability of the starch film was slightly decreased. The biodegradability of the herein developed quaternary nanocomposite films was the same as that of TPS films, eliminating concerns on the supplementation with active ingredients that are expected to have some biocidal effect. Despite checking antimicrobial activity only by contact under the biocomposites, chocolates packed with the films were well accepted by consumers, especially the samples of white chocolate stored in the BSG5 biocomposite. Overall, this new approach towards quaternary active, biodegradable films produced in a pilot-scale lamination unit was successful in either improving or at least maintaining the essential properties of TPS-based films for food packaging applications, while providing them with unique features and functionalities. PRACTICAL APPLICATION: This contribution relates to new approach toward quaternary films produced in a pilot-scale lamination unit. It relates to sustainability as it is both biodegradable and based on plant biomass, as well as produced via a clean, through high-yield process. The four components of the edible films we developed provide it with good in properties performance, as both a passive barrier (i.e. purely physical), and active, related to the sensory attributes of food, essential to be applied in food packaging. The valorization of a BSG also adds to the relevance of our contribution within the circular bioeconomy framework.

Leaking of orbits from the phase space of the dissipative discontinuous standard mapping.

We investigate the escape of particles from the phase space produced by a two-dimensional, nonlinear and discontinuous, area-contracting map. The mapping, given in action-angle variables, is parametrized by K and γ which control the strength of nonlinearity and dissipation, respectively. We focus on two dynamical regimes, K<1 and K≥1, known as slow and quasilinear diffusion regimes, respectively, for the area-preserving version of the map (i.e., when γ=0). When a hole of hight h is introduced in the action axis we find both the histogram of escape times P_{E}(n) and the survival probability P_{S}(n) of particles to be scale invariant, with the typical escape time n_{typ}=exp〈lnn〉; that is, both P_{E}(n/n_{typ}) and P_{S}(n/n_{typ}) define universal functions. Moreover, for γ≪1, we show that n_{typ} is proportional to h^{2}/D, where D is the diffusion coefficient of the corresponding area-preserving map that in turn is proportional to K^{5/2} and K^{2} in the slow and the quasilinear diffusion regimes, respectively.

Effectiveness of Core-Shell Nanofibers Incorporating Amphotericin B by Solution Blow Spinning Against Leishmania and Candida Species.

The aim of this study was to develop polymeric nanofibers for controlled administration of Amphotericin B (AmpB), using the solution centrifugation technique, characterizing its microstructural and physical properties, release rate, and activity against Leishmania and Candida species. The core-shell nanofibers incorporated with AmpB were synthesized by Solution Blow Spinning (SBS) and characterized by scanning electron microscopy (SEM), differential scanning calorimetry, X-Ray diffraction, and drug release assay. In vitro leishmanicidal and antifungal activity were also evaluated. Fibrous membranes with uniform morphology and smooth surfaces were produced. The intensity of the diffraction peaks becomes slightly more pronounced, assuming the increased crystallization in PLA/PEG at high AmpB loadings. Drug release occurred and the solutions with nanofibers to encourage greater incorporation of AmpB showed a higher concentration. In the results of the experiment with promastigotes, the wells treated with nanofibers containing concentrations of AmpB at 0.25, 0.5, and 1%, did not have any viable cells, similar to the positive control. Various concentrations of AmpB improved the inhibition of fungal growth. The delivery system based on PLA/PEG nanofibers was properly developed for AmpB, presenting a controlled release and a successful encapsulation, as well as antifungal and antileishmanial activity.

Advances in Functional Polymer Nanofibers: From Spinning Fabrication Techniques to Recent Biomedical Applications.

Functional polymeric micro-/nanofibers have emerged as promising materials for the construction of structures potentially useful in biomedical fields. Among all kinds of technologies to produce polymer fibers, spinning methods have gained considerable attention. Herein, we provide a recent review on advances in the design of micro- and nanofibrous platforms via spinning techniques for biomedical applications. Specifically, we emphasize electrospinning, solution blow spinning, centrifugal spinning, and microfluidic spinning approaches. We first introduce the fundamentals of these spinning methods and then highlight the potential biomedical applications of such micro- and nanostructured fibers for drug delivery, tissue engineering, regenerative medicine, disease modeling, and sensing/biosensing. Finally, we outline the current challenges and future perspectives of spinning techniques for the practical applications of polymer fibers in the biomedical field.

Non-alcoholic Steatohepatitis: Comparison of Intestinal Microbiota between Different Metabolic Profiles. A Pilot Study.

BACKGROUND AND AIMS: Non-alcoholic steatohepatitis (NASH) has multifactorial etiopathogenesis, and intestinal microbiota is co-responsible in this process. The aim of this study was to evaluate the intestinal microbiota in NASH patients with different metabolic profiles. METHODS: Patients with biopsy-proven NASH were evaluated. Subjects were divided into two groups according to their metabolic profile, with or without metabolic syndrome (MS). Their characteristics in relation to liver disease and intestinal microbiota were analyzed. To evaluate the microbiota, breath tests to investigate small intestinal bacterial overgrowth (SIBO) and fecal microbiota analysis by fluorescence in situ hybridization (FISH) were performed. RESULTS: There was a high prevalence of SIBO in both groups, with no significant difference between them. Breathing tests were positive in 43.8% of patients with MS and 50% of those without MS. There was a significant difference regarding the quantification of Verrucomicrobiales, less abundant in patients with NASH without MS. Its lower concentration also correlated with higher serum ferritin levels and higher hepatocyte ballooning. This order of bacteria, through its representative in human microbiota, Akkermansia muciniphila, is associated with mucosal protection and metabolic processes with liver aggression. CONCLUSIONS: Our results suggested that lower Verrucomicrobiales concentration is associated with higher inflammatory activity in patients with NASH without MS, where the disease etiopathogenesis does not have its classic metabolic substrate.

Effect of carboxymethyl cellulose concentration on mechanical and water vapor barrier properties of corn starch films.

The main objective of this study was to evaluate the effect of the addition of different concentrations of CMC (0, 20, 40, 60, 80 and 100 %) on the mechanical and water vapor barrier properties in corn starch films produced by casting. The addition of CMC 40 % was sufficient to significantly increase its mechanical properties (tensile strength, elongation at break and elastic modulus), and water vapor barrier of the starch films, thus improving its functionality as a packaging material for food. CMC incorporation led to a small reduction in the thermal stability of the films. CMC in low content dispersed well in the starch matrix, ensuring interaction between its constituents that formed a network structure, thus improving mechanical properties and making diffusion of water difficult.