Gelatin-based films are thin, flexible and transparent biodegradable materials based on biopolymers, for use in engineering food, packaging, drug recover and other applications. The addition of ...plasticizer alters some of the functional and physical properties of these films, such as increasing flexibility, moisture sensitivity, as well as other functional properties. However, details on interactions between the biopolymer and plasticizer are not very well known. The purpose of this work was to present and correlate some results of physical measurements of these biopolymer-based films containing different glycerol content. Results show that the plasticizer causes no apparent tendency to re-crystallization in the film structure, but alter other physical properties, such as flexibility, interactions between the macromolecule chains and susceptibility to humidity. Changes observed in the physical properties of the films can be, in principle, attributed to the fact that the plasticizers reduce the interactions between the adjacent chains in the biopolymer affecting thus, the moisture sensitivity and flexibility of the material.
Abstract
We present dynamical measurements for 586 Hα-detected star-forming galaxies from the KMOS (K-band Multi-Object Spectrograph) Redshift One Spectroscopic Survey (KROSS). The sample represents ...typical star-forming galaxies at this redshift (z = 0.6–1.0), with a median star formation rate of ≈7 M⊙ yr−1 and a stellar mass range of log (M⋆M⊙) ≈ 9–11. We find that the rotation velocity–stellar mass relationship (the inverse of the Tully–Fisher relationship) for our rotationally dominated sources (vC/σ0 > 1) has a consistent slope and normalization as that observed for z = 0 discs. In contrast, the specific angular momentum (j⋆; angular momentum divided by stellar mass) is ≈0.2–0.3 dex lower on average compared to z = 0 discs. The specific angular momentum scales as $j_{\rm s}\propto M_{\star }^{0.6\pm 0.2}$, consistent with that expected for dark matter (i.e. $j_{\rm DM}\propto M_{\rm DM}^{2/3}$). We find that z ≈ 0.9 star-forming galaxies have decreasing specific angular momentum with increasing Sérsic index. Visually, the sources with the highest specific angular momentum, for a given mass, have the most disc-dominated morphologies. This implies that an angular momentum–mass–morphology relationship, similar to that observed in local massive galaxies, is already in place by z ≈ 1.
The market of functional foods has experienced a huge growth in the last decades due to the increased consumers’ awareness in a healthy lifestyle. Dried fruits constitute good snacks, in alternative ...to salty or sweet ones, and food ingredients due to their taste and nutritional/health benefits. Bioactive molecules are interesting sources to develop functional foods, as they play a major role in improving the health status and minimizing disease risks. The bioactive compounds most widely discussed in literature are presented in this review, for example, polyphenols, phytosterols, and prebiotics. Different technologies to dry bioproducts for producing functional foods or ingredients are presented. New drying techniques for the preservation of bioactive compounds are proposed, focusing more specifically on dielectric drying. A discussion on the techniques that can be used to optimize drying processes is performed. An overview on dehydrated plant based foods with probiotics is provided. The microorganisms used, impregnation procedures, drying methods, and evaluated parameters are presented and discussed. The principal bioactive compounds responsible for nutritional and health benefits of plant derived dried food products—fruits and vegetables, fruits and vegetables by-products, grains, nuts, and algae—are presented. Phytochemical losses occurring during pretreatments and/or drying processes are also discussed.
Moisture equilibrium data of pineapple pulp (PP) powders with and without additives – 18% maltodextrin (MD) or 18% gum Arabic (GA) – were determined at 20, 30, 40 and 50
°C by using the static ...gravimetric method in a water activity range of 0.06–0.90. The obtained isotherms were sigmoid, typical type III, and the Guggenhein–Anderson–de Boer (GAB) model was fitted to the experimental data of equilibrium moisture content versus water activity. Addition of additives was shown to affect the isotherms in such a way that, at the same water activity, samples PP
+
GA and PP
+
MD presented lower equilibrium moisture content and were not so affected by varying temperature. The net isosteric heats of sorption of pulp powders with additives were higher (less negative) than those of pineapple pulp powders, suggesting that there are more active polar sites in the product without addition of GA or MD. An empirical exponential relationship could describe the heat of sorption dependence on the material moisture content.
Abstract
We analyse the velocity dispersion properties of 472 z ∼ 0.9 star-forming galaxies observed as part of the KMOS Redshift One Spectroscopic Survey (KROSS). The majority of this sample is ...rotationally dominated (83 ± 5 per cent with vC/σ0 > 1) but also dynamically hot and highly turbulent. After correcting for beam smearing effects, the median intrinsic velocity dispersion for the final sample is σ0 = 43.2 ± 0.8 km s−1 with a rotational velocity to dispersion ratio of vC/σ0 = 2.6 ± 0.1. To explore the relationship between velocity dispersion, stellar mass, star formation rate, and redshift, we combine KROSS with data from the SAMI survey (z ∼ 0.05) and an intermediate redshift MUSE sample (z ∼ 0.5). Whilst there is, at most, a weak trend between velocity dispersion and stellar mass, at fixed mass there is a strong increase with redshift. At all redshifts, galaxies appear to follow the same weak trend of increasing velocity dispersion with star formation rate. Our results are consistent with an evolution of galaxy dynamics driven by discs that are more gas rich, and increasingly gravitationally unstable, as a function of increasing redshift. Finally, we test two analytic models that predict turbulence is driven by either gravitational instabilities or stellar feedback. Both provide an adequate description of the data, and further observations are required to rule out either model.
We explore the ionospheric effects of prompt penetration electric fields (PPEFs) for a variety of interplanetary magnetic field directions. We use the great magnetic storm of 30–31 October as an ...example of PPEF effects. For intense southward interplanetary magnetic fields (IMFs), inward plasma sheet convection occurs with the result of magnetospheric ring current formation and an intense magnetic storm. Concurrent with the above, positive phase ionospheric storms occur in the dayside, and negative phase ionospheric storms occur on the nightside, the topics of this paper. The dayside ionospheric storms due to PPEFs are characterized by transport of near‐equatorial plasma to higher altitudes and latitudes, forming a giant plasma fountain. These features are part of what is called the dayside ionospheric superfountain (DIS). For these southward IMFs, dusk and dawn plasma are predicted to be transported toward the dayside. For northward IMFs, negative phase ionospheric storms are expected on the dayside if the PPEFs indeed reach that region of space. IMF By components are expected to have weak or neglible ionospheric effects. On the basis of PPEF arguments, intervals of IMF By should not be related to geomagnetic storms (they are not). IMF By intervals should, however, cause a shearing of the magnetotail, a feature that has been previously reported in the literature.
Interest in the utilization of bioactive plant compounds in foods has increased due to their biochemical activities (antioxidant, antimicrobial, etc.), and as alternatives in the reduction of the use ...of high concentrations of chemical substances. However, some of these additives are hydrophobic, thus being harder to disperse into the food matrix, which is generally water-based. A good alternative is the use of low concentrations of these compounds as nanoemulsions. The objective of the present study was to develop oil-in-water nanoemulsions containing “
dedo-de-moça
” pepper extract for food applications. Research in the development of these nanoemulsions was carried out using a high-speed homogenizer, followed by a high-pressure homogenizer. The influence of the following parameters was assessed: type and concentration of surfactants, hidrophilic-lipophilic balance, lipid/aqueous phase ratio, surfactant/oil ratio, pepper extract composition in nanoemulsion, and processing conditions. Nanoemulsions were evaluated by environmental (centrifugal and thermal) and storage stabilities, characterized by average droplet size and ζ-potential measurements, color, interfacial tension, atomic force, and cryo-scanning electron microscopy. Those with average droplet size between 132 ± 2.0 and 145 ± 1.0 nm were developed depending on working pressure and number of cycles; ζ-potential was around − 36.71 ± 0.62 mV and the best nanoemulsion was stable to centrifugation and most of the thermal stresses. Droplets were characterized with cryo-scanning electron microscopy as being spherical, homogeneous, and stable, and remained stable when stored at 4 °C and room temperature for over 120 days. The pepper nanoemulsion, developed in the present study, has potential applications in the food industry.
Large enhancement in the equatorial electrojet (EEJ) current can occur due to sudden increase in the E layer density arising from solar flare associated ionizing radiations, as also from background ...electric fields modified by magnetospheric disturbances when present before or during a solar flare. We investigate the EEJ responses at widely separated longitudes during two X‐class flares that occurred at different activity phases surrounding the magnetic super storm sequences of 28–29 October 2003. During the 28 October flare we observed intense reverse electrojet under strong westward electric field in the sunrise sector over Jicamarca. Sources of westward disturbance electric fields driving large EEJ current are identified for the first time. Model calculations on the E layer density, with and without flare, and comparison of the results between Jicamarca and Sao Luis suggested enhanced westward electric field due to the flare occurring close to sunrise (over Jicamarca). During the flare on 29 October, which occurred during a rapid AE recovery, a strong overshielding electric field of westward polarity over Jicamarca delayed an expected EEJ eastward growth due to flare‐induced ionization enhancement in the afternoon. This EEJ response yielded a measure of the overshielding decay time determined by the storm time Region 2 field‐aligned current. This paper will present a detailed analysis of the EEJ responses during the two flares, including a quantitative evaluation of the flare‐induced electron density enhancements and identification of electric field sources that played dominant roles in the large westward EEJ at the sunrise sector over Jicamarca.
Key Points
Solar flare causes equatorial electrojet (EEJ) current near sunrise to flow strongly westward under disturbance dynamo electric field
Solar flare‐induced enhanced E layer conductivity longitudinal gradient near sunrise appears to produce large westward electric field
Overshielding westward electric field during storm recovery causes delay in the EEJ response to flare‐induced ionization enhancement
Chitosan (CH) and chitosan-corn starch (CH-CS) film-forming solutions (FFS) and films, with or without polyphenol-rich aqueous extract from murta (Ugni molinae Turcz) leaves (PEML) were prepared. The ...impact of the FFS type and PEML, considering pH values of the FFS, on dynamic and steady-shear behavior of FFS, interaction mechanisms of PEML with polymer chains and changes on infrared spectra of films were investigated. Mechanical properties, thickness and color from films were also evaluated.
Blending CH with PEML produced huge aggregates that were visible to the naked eye. Rheological parameters, K and n, were affected significantly by the FFS type and the PEML presence. Viscosity of both FFS increased with the addition of PEML, leading a gel-like structure and thixotropic behavior. Sol–gel transition occurred when PEML was added to FFS, increasing strongly their elasticity.
The addition of PEML to CH-CS blend film leads to a reduction (p < 0.05) of elongation at break and tensile strength, increasing its thickness and yellow color. The PEML formed electrostatic interactions with chitosan. Ester linkages and hydrogen bonds were also formed between PEML and both chitosan and starch blends.
Display omitted
PDF
