Biopolymers for Medicinal, Macromolecules, and Food Applications II

(1) Background: Adding white vinegar to the batter of a sponge cake without biological fermentation requires the effects of acidification on the batter to be checked, in particular concerning batter-to-crumb transition. (2) Methods: µDSC analyses were carried out on three batters formulated from flour, colza oil, salt, carrot, and water with or without the addition of white vinegar. (3) Results: Wheat, chickpea, and quinoa starches had gelatinization temperatures (T_Ge) of 60.1, 72.4, and 70.5 °C at batter humidity and gelatinization enthalpies (ΔH_Ge) of 9.2, 15, and 9.1 J/g_{dry starch.} Due to the effect of the salt and carrot, the corresponding wholemeal batter had T_Ge of 64.2, 74.1, and 72.4 °C and ΔH_Ge of 10.5, 15.3, and 10.9 J/g_{dry starch}. Acidified batters at pH 4 saw their T_Ge decrease, and their enthalpies increase compared to the controls. The calorimetric study of model mixtures revealed three different evolutions of ΔH_Ge as a function of pH, explained by the isoelectric behavior of flours and/or the attack of starch by acetic acid. (4) Conclusions: These results could be useful for adapting the cooking step of the acid batter in order to produce alternative snacks. Full article

Biocompatible nanogels are highly in demand and have the potential to be used in various applications, e.g., for the encapsulation of sensitive biomacromolecules. In the present study, we have developed water-in-oil microemulsions of sodium alginate sol/hexane/Span 20 as a template for controlled synthesis of alginate nanogels, cross-linked with 3d transition metal cations (Mn²⁺, Fe³⁺, and Co²⁺). The results suggest that the stable template of 110 nm dimensions can be obtained by microemulsion technique using Span 20 at concentrations of 10mM and above, showing a zeta potential of −57.3 mV. A comparison of the effects of the cross-links on the morphology, surface charge, protein (urease enzyme) encapsulation properties, and stability of the resulting nanogels were studied. Alginate nanogels, cross-linked with Mn²⁺, Fe³⁺, or Co²⁺ did not show any gradation in the hydrodynamic diameter. The shape of alginate nanogels, cross-linked with Mn²⁺ or Co²⁺, were spherical; whereas, nanogels cross-linked with Fe³⁺ (Fe–alginate) were non-spherical and rice-shaped. The zeta potential, enzyme loading efficiency, and enzyme activity of Fe–alginate was the highest among all the nanogels studied. It was found that the morphology of particles influenced the percent immobilization, loading capacity, and loading efficiency of encapsulated enzymes. These particles are promising candidates for biosensing and efficient drug delivery due to their relatively high loading capacity, biocompatibility, easy fabrication, and easy handling. Full article

The problem of waste generated by packaging obtained from conventional synthetic materials, often multilayer, has become more and more pressing with increasing consumption. In this context, nature and humanity have suffered the most. In order to address this phenomenon, global and European organizations have launched and promoted programs and strategies. Replacing petroleum-based packaging with biopolymer packaging has proven to be a real alternative. Thus, the substitution of plastics with biodegradable, non-toxic, edible materials, which can be obtained from marine or agro-industrial waste, is of interest. In the present study, we aimed to develop natural edible materials, obtained entirely from biopolymers such as agar and sodium alginate and plasticized with glycerol and water. Designed to be used for food and food supplements packaging, they can be completely solubilized before consumption. The films were developed through a casting method and were tested in order to identify the physical, optical, and solubility properties. According to the results, the most suitable composition for use as a hydrosoluble packaging material contains agar:alginate:glycerol in a 2:1:1 ratio. The microstructure indicates a homogeneous film, with low roughness values (Rz = 12.65 ± 1.12 µm), high luminosity (92.63), above-average transmittance (T = 51.70%), and low opacity (6.30 A* mm⁻¹). The obtained results are of interest and highlight the possibility of substituting intensely polluting materials with those based on biopolymers. Full article

In this study Bacillus amyloliquefaciens RK3 was isolated from a sugar mill effluent-contaminated soil and utilised to generate a potential polysaccharide with anti-Alzheimer’s activity. Traditional and molecular methods were used to validate the strain. The polysaccharide produced by B. amyloliquefaciens RK3 was purified, and the yield was estimated to be 10.35 gL⁻¹. Following purification, the polysaccharide was structurally and chemically analysed. The structural analysis revealed the polysaccharide consists of α-d-mannopyranose (α-d-Manp) and β-d-galactopyranose (β-d-Galp) monosaccharide units connected through glycosidic linkages (i.e., β-d-Galp(1→6)β-d-Galp (1→6)β-d-Galp(1→2)β-d-Galp(1→2)[β-d-Galp(1→6)]β-d-Galp(1→2)α-d-Manp(1→6)α-d-Manp (1→6)α-d-Manp(1→6)α-d-Manp(1→6)α-d-Manp). The scanning electron microscopy and energy-dispersive X-ray spectroscopy imaging of polysaccharides emphasise their compactness and branching in the usual tubular heteropolysaccharide structure. The purified exopolysaccharide significantly impacted the plaques formed by the amyloid proteins during Alzheimer’s disease. Further, the results also highlighted the potential applicability of exopolysaccharide in various industrial and pharmaceutical applications. Full article

In the present study, the modification of branched polyethyleneimine (b-PEI) was carried out using mesquite gum (MG) to improve its hemocompatibility to be used in biomedical applications. In the copolymer synthesis process (carboxymethylated mesquite gum grafted polyethyleneimine copolymer (CBX-MG-PEI), an MG carboxymethylation reaction was initially carried out (carboxymethylated mesquite gum (CBX-MG). Subsequently, the functionalization between CBX-MG and b-PEI was carried out using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as crosslinking agents. The synthesis products were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Thermogravimetric analysis showed that CBX-MG and CBX-MG-PEI presented a lower decomposition temperature than MG. The CBX-MG-PEI has a high buffer capacity in the pH range of 4 to 7, similar to the b-PEI. In addition, the CBX-MG-PEI showed an improvement in hemocompatibility in comparison with the b-PEI. The results showed a non-hemolytic property at doses lower than 0.1 µg/mL (CBX-MG-PEI). These results allow us to propose that this copolymer be used in transfection, polymeric nanoparticles, and biomaterials due to its physicochemical and hemocompatibility properties. Full article

Pelizaeus–Merzbacher disease (PMD), also known as hypomyelinating leukodystrophy 1 (HLD1), is an X-linked recessive disease affecting in the central nervous system (CNS). The gene responsible for HLD1 encodes proteolipid protein 1 (plp1), which is the major myelin structural protein produced by oligodendroglial cells (oligodendrocytes). HLD15 is an autosomal recessive disease affecting the glutamyl-prolyl-aminoacyl-tRNA synthetase 1 (eprs1) gene, whose product, the EPRS1 protein, is a bifunctional aminoacyl-tRNA synthetase that is localized throughout cell bodies and that catalyzes the aminoacylation of glutamic acid and proline tRNA species. Here, we show that the HLD15-associated nonsense mutation of Arg339-to-Ter (R339X) localizes EPRS1 proteins as polymeric aggregates into Rab7-positive vesicle structures in mouse oligodendroglial FBD-102b cells. Wild-type proteins, in contrast, are distributed throughout the cell bodies. Expression of the R339X mutant proteins, but not the wild-type proteins, in cells induces strong signals regulating Rab7. Whereas cells expressing the wild-type proteins exhibited phenotypes with myelin web-like structures bearing processes following the induction of differentiation, cells expressing the R339X mutant proteins did not. These results indicate that HLD15-associated EPRS1 mutant proteins are localized in Rab7-positive vesicle structures where they modulate Rab7 regulatory signaling, inhibiting cell morphological differentiation. These findings may reveal some of the molecular and cellular pathological mechanisms underlying HLD15. Full article

Skin aging is caused by exposure to various external factors. Ultraviolet B (UVB) irradiation induces oxidative stress, photoaging, and inflammation in skin cells. Pinus densiflora Sieb. et Zucc. (red pine) has various antimicrobial and antioxidant activities. However, the anti-inflammatory effects of red pine on skin have rarely been reported. The protective effects of malonic acid (MA) isolated from Pinus densiflora were investigated against UVB-induced damage in an immortalized human keratinocyte cell line (HaCaT). MA increased levels of the antioxidant enzymes superoxide dismutase 1 (SOD-1) and heme oxygenase 1 (HO-1) via activation of nuclear factor-erythroid 2-related factor-2 (Nrf2), resulting in a reduction in UVB-induced reactive oxygen species (ROS) levels. Additionally, the inhibition of ROS increased HaCaT cell survival rate. Thus, MA downregulated the expression of ROS-induced nuclear factor-κB, as well as inflammation-related cytokines (interleukin-6, cyclooxygenase-2, and tumor necrosis factor-α). Furthermore, MA significantly suppressed the mitogen-activated protein kinase/activator protein 1 signaling pathway and reduced the expression of matrix metalloproteinases (MMPs; MMP-1, MMP-3, and MMP-9). In contrast, MA treatment increased the expression of collagen synthesis regulatory genes (COL1A1 and COL3A1) via regulation of Smad2/3 signal induction through transforming growth factor-β. In conclusion, MA protected against UVB-induced photoaging via suppression of skin inflammation and induction of collagen biosynthesis. Full article

Citrus essential oils possess many health-promoting benefits and properties of high interest in the food and agri-food sector. However, their large-scale application is limited by their sensitivity to environmental factors. Nanostructures containing citrus essential oils have been developed to overcome the high volatility and instability of essential oils with respect to temperature, pH, UV light, etc. Nanostructures could provide protection for essential oils and enhancement of their bioavailability and biocompatibility, as well as their biological properties. Nano-encapsulation is a promising method. The present review is mainly focused on methods developed so far for the nano-encapsulation of citrus essential oils, with emphasis on lipid-based (including liposomes, solid lipid nanoparticles, nanostructured lipid particles, and nano- and micro-emulsions) and polymer-based nanostructures. The physico-chemical characteristics of the obtained structures, as well as promising properties reported, with relevance for the food sector are also discussed. Full article

Biopolymers are a leading class of functional material suitable for high-value applications and are of great interest to researchers and professionals across various disciplines. Interdisciplinary research is important to understand the basic and applied aspects of biopolymers to address several complex problems associated with good health and well-being. To reduce the environmental impact and dependence on fossil fuels, a lot of effort has gone into replacing synthetic polymers with biodegradable materials, especially those derived from natural resources. In this regard, many types of natural or biopolymers have been developed to meet the needs of ever-expanding applications. These biopolymers are currently used in food applications and are expanding their use in the pharmaceutical and medical industries due to their unique properties. This review focuses on the various uses of biopolymers in the food and medical industry and provides a future outlook for the biopolymer industry. Full article

In recent years, scientists have focused on research to replace petroleum-based components plastics, in an eco-friendly and cost-effective manner, with plant-derived biopolymers offering suitable mechanical properties. Moreover, due to high environmental pollution, global warming, and the foreseen shortage of oil supplies, the quest for the formulation of biobased, non-toxic, biocompatible, and biodegradable polymer films is still emerging. Several biopolymers from varied natural resources such as starch, cellulose, gums, agar, milk, cereal, and legume proteins have been used as eco-friendly packaging materials for the substitute of non-biodegradable petroleum-based plastic-based packaging materials. Among all biopolymers, starch is an edible carbohydrate complex, composed of a linear polymer, amylose, and amylopectin. They have usually been considered as a favorite choice of material for food packaging applications due to their excellent forming ability, low cost, and environmental compatibility. Although the film prepared from bio-polymer materials improves the shelf life of commodities by protecting them against interior and exterior factors, suitable barrier properties are impossible to attain with single polymeric packaging material. Therefore, the properties of edible films can be modified based on the hydrophobic–hydrophilic qualities of biomolecules. Certain chemical modifications of starch have been performed; however, the chemical residues may impart toxicity in the food commodity. Therefore, in such cases, several plant-derived polymeric combinations could be used as an effective binary blend of the polymer to improve the mechanical and barrier properties of packaging film. Recently, scientists have shown their great interest in underutilized plant-derived mucilage to synthesize biodegradable packaging material with desirable properties. Mucilage has a great potential to produce a stable polymeric network that confines starch granules that delay the release of amylose, improving the mechanical property of films. Therefore, the proposed review article is emphasized on the utilization of a blend of source and plant-derived mucilage for the synthesis of biodegradable packaging film. Herein, the synthesis process, characterization, mechanical properties, functional properties, and application of starch and mucilage-based film are discussed in detail. Full article