Macromol

Arundo donax L. is a plant with great potential as lignocellulosic biomass, being a promising source for the development of biodegradable materials. This study evaluated the effects of different chemical pretreatments (H₂SO₄, NaOH, and NaClO) combined with dry milling on the physicochemical properties of biomass. Pretreatment with NaClO was the most effective in removing lignin, reducing its content to 0.2%, while increasing the cellulose content to 67%. Pretreatment with H₂SO₄, although retaining a higher lignin content (24%), resulted in the greatest reduction in particle size, reaching a mean diameter (Dm) of 44.31 µm after 20 h of milling. Density analysis revealed that the raw samples reached a maximum density of 0.218 g/cm³ after 20 h of milling, with the pretreated samples showing lower densities due to the removal of structural components. Thermal analysis showed mass losses of up to 66.4% for samples pretreated with NaClO after 10 h of milling, indicating significant structural changes and improved thermal stability. Morphological analysis via SEM demonstrated elongated and fine particles, with acid pretreatment resulting in the most pronounced structural changes. These findings highlight the efficiency of combining chemical and physical pretreatments to modify the structure of A. donax L., optimizing its properties for the production of high-performance biodegradable materials. Full article

The study of the techno-functional properties of novel plant-based proteins has gained importance due to their as alternatives to conventional proteins in food systems. This work evaluated the techno-functional and structural properties of white bean protein concentrate (WBPC) in comparison with commercial soy and pea proteins. The WBPC exhibited a higher foaming capacity (FC) at neutral pH and excellent foam stability (FS) at both tested pH levels, outperforming the commercial proteins. Although the WBPC’s gelation occurred only at concentrations above 16% and its water-holding capacity (WHC) was lower than that of the soy and pea proteins, the WBPC showed a high binding capacity for nonpolar molecules, excelling in its oil-holding capacity (OHC) and forming stable emulsions, which are relevant for stabilization in food products. Additionally, WBPC can form more rigid gel networks, suitable for systems requiring greater mechanical strength. These techno-functional properties indicate that WBPC is a promising alternative source for the plant-based food industry, helping to meet the demand for innovative, sustainable products and contributing to the diversification of protein sources. Full article

Isothermal titration calorimetry (ITC) is a widely used and valuable technique for studying the binding interactions and the formation and dissociation of molecular complexes. ITC directly measures the energetics associated with the interactions and allows for a precise and complete thermodynamic description of association and binding processes, thereby providing an understanding of the interaction mechanisms. In this review, the role, practical aspects related to the experimental design and setup, advantages, and challenges of using ITC to evaluate polyphenol–macromolecule binding are discussed in detail. The focus is on the possibilities offered by ITC, but at the same time, its limitations are taken into account, especially in the study of complex biological processes and in the subsequent reliable determination of thermodynamic parameters. Polyphenols and proteins typically exhibit exothermic interactions, producing strong signals and distinctive titration curves that can be fitted by one- or two-site binding models; of course, there are exceptions to this. Tannins and tannin fractions usually have a high binding stoichiometry and stronger interactions with proteins than the smaller polyphenols. The driving forces behind these interactions vary, but in many cases, both hydrogen bonding and hydrophobic interactions have been reported. The interactions between polyphenols and polysaccharides or lipid bilayers have been far less studied by ITC in comparison to polyphenol–protein interactions. ITC could be utilized more extensively to study polyphenol–macromolecule interactions, as it is an excellent tool for evaluating the thermodynamic parameters of these interactions, and when used together with other techniques, ITC can also help understand how these interactions affect bioavailability, food applications, and other uses of polyphenols. Full article

The objective of this study was to examine the changes in starch processed under various ohmic heating (OH) conditions in relation to the characteristics of nixtamalized maize. Ground and dehydrated nixtamalized doughs (masas) were analyzed. Samples were prepared using both OH and traditional nixtamalization methods for comparison. The OH process variables included cooking temperature (85 and 90 °C), heating time (0, 5, and 10 min), and voltage (120 and 130 V). Starch modifications were assessed through viscosity measurements, differential scanning calorimetry (DSC), X-ray diffraction, and scanning electron microscopy (SEM). The results showed that viscosity in OH-treated samples was influenced by both thermal conditions (time and temperature) and the electric field (at 130 V), due to gelatinization and electroporation, evidenced by starch granule damage in SEM. DSC and X-ray diffraction revealed gelatinization and a loss of crystalline structures, along with new interactions between starch components that stabilized the system and reduced peak viscosity in the OH masa flours. Full article

The increasing industrial demand and the search for novel ingredients in food and non-food sectors have driven research efforts toward alternatives to traditional commercial starches, emphasizing sustainability and the valorization of native crops, thereby promoting income generation for small-scale farmers. The extraction of these starches through aqueous methods, employing reductive and/or alkaline agents, can impact their structure and technological properties. These starches exhibit distinct physicochemical, morphological, crystalline, thermal, and nutritional characteristics, influenced by factors such as botanical origin. Although certain limitations may exist in their technological applications, physical, chemical, and/or enzymatic modification methods, or a combination thereof, are employed to enhance these properties for specific uses. These alternative starch sources present potential applications across the food, pharmaceutical, paper, medicinal, and cosmetic industries, underscoring their versatility and unique advantages. Nonetheless, ongoing research is essential to fully explore their composition and potential applications. This review serves as a valuable resource for researchers and professionals interested in sustainable and innovative alternatives to conventional starches. Full article

Lipases and carboxylesterases are enzymes of biotechnological interest both for their reactions and their specificity. They have wide-ranging applications in the food, pharmaceuticals, biodiesel synthesis, and bioremediation industries. For that reason, the strain Neobacillus thermocopriae C255 was isolated from ash from Popocatepetl volcano and studied as a new source of lipolytic enzymes. It was identified using 16S ribosomal RNA and flagellar protein FliF sequence homology, yielding 100% identity. From the sequencing of its genome, an enzyme with lipolytic activity, classified as a monoacylglycerol lipase, and named Mgl-C255, was cloned in E. coli BL21, and then expressed, biochemically characterized, and tested via transesterification reactions with alcohols and monosaccharides. Based on its sequence and structure, it was placed within family V, having a catalytic triad of S90-D207-H237. Biochemical characterization showed its highest activity at 40 °C, pH 7.5 to 8.5, with C-2 length substrate preference. No metal ions or inhibitors influenced lipolytic activity, except for PMSF, SDS, Cu⁻², and Hg⁻². Mgl-C255 retained about 50% of its activity in non-polar solvents and showed synthetic activity in organic solvents, making it a good candidate for studying its catalytic potential and selectivity. Full article

The MALDI-TOF mass-spectrometry was employed to analyze the structure of the reaction products of limonene, a natural terpene, and elemental sulfur, with the objective of identifying the occurrence of side processes, such as oxidative dehydrogenation, aromatization, and the Diels–Alder reaction cascade. The MALDI-TOF mass-spectrometry was demonstrated to be effective for the analysis of high-sulfur polymers obtained by the inverse vulcanization reaction, allowing for the unambiguous separation of sulfur-containing and hydrocarbon molecular fragments and the detailed characterization of macromolecular structures. By varying the ratio of sulfur (S₈) and limonene in the initial reaction system, we were able to ascertain the limiting amount of sulfur that can be covalently bonded by terpene, as well as determine the average length of polysulfide chains under the assumption of equal reactivity and complete depletion of all double bonds. The side reaction of limonene aromatization, as indicated by the MALDI-TOF spectrum of the product resulting from its interaction with elemental sulfur, was corroborated by ¹H and ¹³C NMR spectroscopy. Consequently, the registration and interpretation of MALDI-TOF spectra of inverse vulcanization products, either independently or in conjunction with the application of ¹H and ¹³C NMR spectroscopy methods, as well as the determination of the limiting number of sulfur atoms that can be bound to one molecule of an unsaturated compound, paves the way for new avenues of investigation into the structure and side reactions involved in the synthesis of high-sulfur polymers. Full article

Hydroxypropyl-β-cyclodextrin (HPβCD) is a derivatized cyclodextrin in which several H atoms on the hydroxyls of the glucose rings are substituted by 2-hydroxypropyl groups. The cyclic structure of HPβCD creates a cavity capable of totally or partially enclosing different molecules (inclusion complexes), and this capacity makes it useful in the pharmaceutical industry. Rifampicin is an antibiotic commonly used to treat tuberculosis; however, some of its properties such as its low solubility and variable bioavailability need to be improved by encapsulating it in systems such as HPβCD. The inclusion complexes formed by twelve structures of HPβCD and rifampicin with various polar and non-polar solvents are studied using molecular simulation. Diverse solvents are simulated using the zwitterionic or neutral configuration of rifampicin, and different values of relative permittivity in the electrostatic contribution to the total energy. The latter constant has little effect on the formation of inclusion complexes, whereas the type of rifampicin essentially determines the energies and configurations of the complexes. The zwitterion is located near the primary rim of HPβCD and the neutral form of rifampicin is near the secondary one. In both cases, the piperazine tail is incorporated into higher-energy complexes inside the host. Full article

Plant-derived phenolic compounds are recognized to provide several health benefits for humans, including anticancer, anti-inflammatory, and antioxidant proprieties. Their bioavailability in the human body has a significant impact on these outcomes. Their bioaccessibility and bioavailability are highly dependent on the structure and manner in which phenolics enter into the organism, through a complex food matrix, for instance, or as pure isolates. Furthermore, the bioaccessibility of phenolic compounds in the body is greatly impacted by interactions with a broad range of other macromolecules (such as proteins, lipids, dietary fibers, and polysaccharides) in food or during digestion. Encapsulation is a process that can improve bioaccessibility and bioavailability by guaranteeing coating of the active ingredients, controlled release, and targeted distribution to specific parts of the digestive system. However, this field has not yet received enough attention, due to the complex mechanisms through which phenolics act in the body. This review attempts to shed light on the results of research that has been performed on the potential and therapeutic benefits of encapsulated polyphenols in both health and disease. Full article

Agrochemical residues, including pesticides and herbicides, pose significant environmental and health risks when present in water sources. Conventional water treatment methods often fall short in effectively removing these persistent pollutants, necessitating innovative solutions. This review explores the use of polysaccharides and composite adsorbents as sustainable alternatives for agrochemical residue removal from water. Biopolymers such as chitosan, alginate, and cellulose are highlighted for their biodegradability, biocompatibility, and ability to be functionalized for enhanced adsorption performance. Recent advances in the development of composite materials incorporating nanomaterials, such as graphene, oxide, and metal oxides, have shown significant promise in enhancing the efficiency and selectivity of agrochemical adsorption. The review also addresses the fundamental mechanism of adsorption, such as electrostatic interactions, hydrogen bonding, and hydrophobic forces, that contribute to the effectiveness of these materials. Challenges associated with scalability, regeneration, and real-world applications are discussed, as well as future opportunities for integrating emerging technologies like 3D printing and machine learning into adsorbent design. Overall, polysaccharides and composites offer a promising pathway toward achieving efficient and sustainable agrochemical residue removal, with ongoing research needed to overcome current limitations and optimize their practical application in water treatment. Full article

Biopolymer blends of polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) are extruded into flexible monolayer films. These blends are excellent candidates for the realization of environmentally friendly packaging applications. A necessary pre-requisite for that are appropriate tribological properties under mechanical contact. Reasonable wear resistance allows good protection of packed goods, and low friction forces reduce difficulties in stacking. In this research, mechanical embossment under high loads at room temperature was used for the modification of polymer surfaces to exhibit a significant friction reduction under dry conditions. The results particularly show a systematic decrease in the coefficient of friction for biopolymer blends containing 30 wt% and 40 wt% PBAT. FTIR was used to analyze the change in surface composition after mechanical embossing. A sophisticated FTIR calibration method revealed that the blend with 30 wt% PBAT shows a modified distribution of PBAT and PLA at the surface due to mechanical embossment. This leads to a controlled and long-lasting modification of the surface properties without a substantial change in the chemical composition of the polymer in bulk. Without the use of additional coatings, biodegradable packaging foils with improved characteristics are accessible. Full article

Bacterial quorum sensing (QS) is a critical communication process that regulates gene expression in response to population density, influencing activities such as biofilm formation, virulence, and antibiotic resistance. This study investigates the inhibitory effects of five phytochemicals—apigenin, carnosol, chlorogenic acid, quercetin, and rosmarinic acid—on the S-ribosylhomocysteinase (LuxS) enzyme, a key player in AI-2 signaling across both Gram-positive and Gram-negative bacteria. Using molecular docking studies, we identified that these phytochemicals interact with the LuxS enzyme, with apigenin, carnosol, chlorogenic acid, and rosmarinic acid binding within the substrate-binding pocket and exhibiting binding scores below −7.0 kcal/mol. Subsequent in vitro assays demonstrated that these compounds inhibited AI-2 signaling and biofilm formation in Escherichia coli MG1655 in a concentration-dependent manner. Notably, carnosol and chlorogenic acid showed the most potent effects, with IC₅₀ values of approximately 60 μM. These findings suggest that these phytochemicals may serve as potential QS inhibitors, providing a foundation for developing new anti-pathogenic agents to combat bacterial infections without promoting antibiotic resistance. Further studies are warranted to explore the therapeutic applications of these compounds in both clinical and agricultural settings. Full article

During the manufacturing of wooden musical instruments, offcut wood pieces are inevitably generated. This study explores the potential of utilizing three types of these small offcut wood pieces, mahogany, maple, and rosewood, by converting them into polyurea through liquefied wood technology by proposing a novel approach to synthesizing bio-based polyurea. This polyurea is a durable polymer, offering long-term carbon fixation and thereby contributing to environmental sustainability. In this study, various liquefaction conditions as parameters, including the temperature, sulfuric acid content, mix solvent ratio, and liquefaction time, were investigated in relation to polyurea film properties. The relationship between the mechanical and thermal properties of the resulting films and the characteristics of the liquefied product was investigated. Notably, when the hydroxyl value of the liquefied product exceeded 300, the resulting polyurea derived from the liquefied product exhibited a high tensile strength of 25 MPa. In contrast, when the hydroxyl value was below 300, the polyurea derived from the liquefied product displayed a strain value of up to 150%, alongside an increased thermal decomposition temperature. These findings suggest that the properties of polyurea can be effectively tuned by manipulating the characteristics of the liquefied product, offering a promising approach to enhancing the value of offcut wood in instrument manufacturing. Full article

Natural fiber composites have gained increasing attention due to sustainability considerations. One often neglected aspect is the potential for the mechanical recycling of such materials. In this work, we compounded injection-molded polypropylene (PP) and polylactic acid (PLA) short cellulose fiber composites with fiber shares up to 40 percent by weight. Both matrix materials were reinforced by the addition of the fibers. We investigated a trifold full recycling process, where we subjected the materials produced in the first place to compounding, injection molding, testing, and shredding, and then repeated the process. Although the materials’ properties assigned to degradation were found to decrease with progressive recycling, attractive mechanical properties could be preserved even after the third reprocessing cycle. Full article

The development and characterization of agricultural byproduct-based biocomposites are an important part of green chemistry. In this work, four-ingredient blends were formulated with the melt blending method. The set of composites (named as CSO series) was made with poly(lactic acid) (PLA) as the major matrix, washed cottonseed meal (WCSM) as a filler, cottonseed oil (CSO) as a compatibilizer, and glycerol (GLY) as a plasticizer. The morphological analysis showed the homogenous dispersion of the cottonseed byproducts into the PLA matrix to some extent. The thermogravimetric analysis revealed that thermal stability was impacted by the ingredient’s addition. The functional group analysis of the sample and simulation by Fourier transform infrared spectra confirmed the chemical interactions of PLA with WCSM in the blend products. CSO was most likely subjected to physical blending into the products. The mechanical strengths of those composites were affected by the ratios of PLA-CSO. Generally, the tensile strengths were in the range of 0.74–2.1 MPa, which indicate its suitability for low-strength biodegradable plant container development. The blend products had a lower water absorption during the water soaking test. This work shows the feasibility of incorporating cottonseed WCSM and CSO into a PLA composite for sustainable agricultural applications. Full article

The interaction of poly(trimethylene carbonate) (PTMC) with hydroxyl group compounds was investigated as a model for polymer blending with polysaccharides. While 1-butanol, 2-butanol, ethylene glycol, and 1,2-cyclohexanediol showed almost no detectable interaction with PTMC in both solution states with the ¹H NMR and solid states with the FT-IR, glucose and cellobiose suggested a slight change in the spectral pattern in FT-IR analysis. The thermal properties of the blended samples of PTMC and these hydroxyl groups were also investigated. Although the blends of PTMC with 1-butanol and 2-butanol did not influence thermal degradation behaviors due to their low boiling points, the PTMC blend with a higher number of hydroxyl groups, especially glucose and cellobiose, tended to increase thermal resistance and glass transition temperature, hence showing the existence of an interaction through hydrogen bonding. Full article

A Leuconostoc mesenteroides strain (SJC113) isolated from cheese curd was found to produce large amounts of a mucoid exopolysaccharide (EPS). An analysis revealed the glucan nature of the EPS with 84.5% (1→6)-linked α-d-glucose units and 5.6% (1,3→6)-linked α-d-glucose units as branching points. The EPS showed 52% dextranase resistance and a yield of 7.4 ± 0.9 g/L from MRS medium supplemented with 10% sucrose within 48 h. Ln. mesenteroides SJC113 was also characterized and tested for the production of EPS as a fat substitute in fresh cheese. Strain SJC113 showed high tolerance to a wide range of NaCl concentrations (2, 5 and 10%), high β-galactosidase activity (2368 ± 24 Miller units), cholesterol-reducing ability (14.8 ± 4.1%), free radical scavenging activity (11.7 ± 0.7%) and hydroxyl scavenging activity (15.7 ± 0.4%). The strain had no virulence genes and was sensitive to clinically important antibiotics such as ampicillin, tetracycline and chloramphenicol. Ln. mesenteroides SJC113 produced highly viscous EPS during storage at 8 °C in skim milk with 5% sucrose. Therefore, these conditions were used for EPS production in skim milk before incorporation into fresh cheese. Four types of fresh cheese were produced: full-fat cheese (FF) made from pasteurized whole milk, non-fat cheese (NF) made from pasteurized skim milk, non-fat cheese made from skim milk fermented with Ln. mesenteroides without added sugar (NFLn0) and non-fat cheese made from skim milk fermented with Ln. mesenteroides with 5% sucrose (NFLn5). While the NF cheeses had the highest viscosity and hardness, the NFLn5 cheeses showed lower firmness and viscosity, higher water-holding capacity and lower weight loss during storage. Overall, the NFLn5 cheeses had similar rheological properties to full-fat cheeses with a low degree of syneresis. It was thus shown that the glucan-type EPS produced by Ln. mesenteroides SJC113 can successfully replace fat without altering the texture of fresh cheese. Full article

With the world population rising, wheat straw production is expected to reach 687–740 million tons per year by 2050. Its frequent application as a fuel source leads to air, water, and soil pollution. Limited literature exists on methods for separating components of residual wheat straw. Optimal conditions for organosolv pulping of hydrolyzed wheat straw include 3% FeCl₃·6H₂O as a catalyst, a biomass-to-solvent ratio of 1:15 (m/v), and 50% ethanol:water as cooking liquor at 200 °C for 30 min. Desilication conditions involve extraction with 7.5% Na₂CO₃ at a biomass-to-solvent ratio of 1:20 (m/v) treated at 115 °C for 60 min. Lignin from hydrolyzed wheat straw showed similar properties to organosolv lignin from untreated straw, with minimal lignin alteration during hydrolysis. Hydrolysis significantly degraded cellulose. A 41% lignin recovery rate with 95% purity was achieved from pre-extracted hydrolyzed straw. Recovered cellulose after silica removal had 2% ash and 87% purity. The innovation of this process lies in the development of a comprehensive, sustainable, efficient, and economically viable biorefinery process that efficiently separates key components of wheat straw, i.e., xylose, lignin, cellulose, and silica, while addressing environmental pollution associated with its traditional use as fuel. Full article

The combination of different wood-modification technologies to obtain improved performance is increasingly receiving attention in research. In this study, Scots pine (Pinus sylvestris) sapwood was impregnated with furfuryl alcohol (FFA) in pure aqueous 20, 40, and 60% solution strength without adding any catalyst. In a second step, the FFA was polymerized while simultaneously performing thermal modification in a closed system at 130, 150, or 180 °C. After leaching and ageing tests, the nine different combinations were tested in use class 4 applications (in contact with or very close to the ground and frequently wet) according to CEN/TS 15083-2 (2005) decay laboratory test. It was noted that even the minimum-intensity combination of 20% FFA at 130 °C resulted in maximum durability class (DC) 1 performance. On the contrary, DC 4 was assigned to thermally modified control samples, even at the maximum intensity of thermal modification. Similarly, for FFA modifications, previous research has suggested that an uptake of 35% solution strength is required to obtain an adequate durability performance in use class 4 applications. High levels of resistance against termites were also noted by corresponding termite lab tests. Moisture studies showed the combined treatments resulted in improved stability and reduced moisture uptakes. Thus, the results obtained by this study revealed synergistic performance effects, which originate from the combined thermo-chemical modification approach, and which were higher than simple accumulation of the individual performance of purely thermally or chemically modified wood. Thus, the presented findings have provided positive implications for industrial applications of thermo-chemical modification techniques and offers an array of new research opportunities. Full article