Search Results (200)

Plastic pollution in terrestrial and freshwater environments and its accumulation along food chains has been poorly studied in birds. In this paper we reported evidence of microplastic (MP) contamination in pellets collected in rural and urban sites for a set of species: common kestrel, Falco tinnunculus; great cormorant, Phalacrocorax carbo; barn owl, Tyto alba; little owl, Athene noctua; long-eared owl, Asio otus; Eurasian scops owl, Otus scops; European bee-eater, Merops apiaster; and little egret, Egretta garzetta. A total of 559 pellets were collected and analyzed; among them, 78 microplastics were found on 77 pellets (13.8% compared to the total number of pellets sampled). The following polymers were recorded: polyvinylchloride (PVC), polyethylene (PE), expanded polyester (EPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester (PES), polymethyl acrylate (PMA), rubber, and starch-based biopolymer. We found significantly higher MP frequency in the most anthropized site. Pellets with the highest number of microplastics were those produced by Falco tinnunculus, Asio otus, and Tyto alba, with 30.0%, 29.6%, and 27.1%, respectively. Of a total sample of 78 MP items, 59.0% are represented by fibers, 23.1% by fragments and 17.9% by films. Among the microplastics, fragments of balloons (in a remote area) and biopolymer shopping bags were found. Our results suggest that pellet analysis may represent a cost-effective method for monitoring MP contamination along food chains in terrestrial ecosystems. Full article

Biopolymers (BPs), obtained from urban and agricultural wastes, are known as active principles to manufacture ready-for-use finished products in several sectors of the agriculture and chemical industries. These findings prospect a biowaste-based refinery producing chemical specialities to replace products derived from fossil feedstock. The present paper reports new materials containing BPs. Composite granules containing Poly(Butylene Adipate-Co-Terephthalate (PBAT) as a matrix and BPs as fillers are manufactured by twin-screw extrusion. The granules are used to make single-layer PBAT-BP mulch films by single-screw extrusion and three-layer Starch-PBAT-BP films by blown co-extrusion. The films are tested for mechanical properties, and for structural stability and effects in the in vitro cress germination and the in-field horticulture. The results show that both the films’ effects on plant performance and the films’ structural degradation are regulated by the BP and polymeric matrix release kinetics in the operational germination medium or the field soil, and in turn, that the kinetics depend on the mulch film structural features. The horticulture trials prove that the three-layer mulch films have adequate mechanical strength (25 MPa maximum tensile strength and 520% elongation at break) and about 6 months lifespan to maintain and/or improve the soil protection and crop production (17 t/ha) over the plant seasonal cycle. These findings widen the range of renewable chemical specialities potentially producible by the envisioned biowaste-based refinery. Full article

The environmental impact of food waste and agro-industrial by-products has promoted the development of circular economy strategies for food applications. In this study, edible films were developed from biopolymers extracted from avocado peel and seeds (hemicellulose, pectin, lignin, and starch), incorporating ethyl lauroyl arginate (LAE^®) as an antifungal agent. The activity of LAE^® was evaluated against Colletotrichum gloeosporioides on inoculated avocados stored at 12 °C and 22 °C. Fruit shelf life was assessed through physiological, physicochemical and sensory parameters during cold storage and subsequent shelf life. Films containing 10% LAE^® exhibited strong antifungal activity, and their efficacy was higher at 12 °C than at 22 °C. Coated fruits exhibited a ripening delay of up to 2 days compared to controls. These findings highlight the potential use of avocado by-product-based LAE^® coatings as a sustainable strategy for preserve postharvest avocado quality. Full article

This study investigates agar–starch composite bioplastic films formulated with five agar-to-starch ratios (1:1, 2:1, 3:1, 4:1, and 5:1) to evaluate how composition influences material performance. Films were produced by solution casting with glycerol as a plasticizer and characterized through tensile testing (ASTM D882-18), DSC, TGA, FTIR, water absorption measurements, physical property assessment, and biodegradability tests including water, UV, and soil degradation. Mechanical results showed that the 3:1 formulation (A3S1) exhibited the highest tensile strength (2.78 MPa) with moderate elongation (57.25%), while the 1:1 formulation (A1S1) showed the greatest flexibility (76.38% elongation) but lower strength (2.07 MPa). Thermal analysis indicated improved thermal stability with increasing agar content, with onset degradation temperatures ranging from 42.89 °C to 51.84 °C and melting points from 99 °C to 108 °C. FTIR spectra showed no new major absorption bands, with only minor shifts in selected bands, indicating component interactions without evidence of new chemical bond formation. Films with higher starch content displayed increased thickness, weight per area, and water absorption. Overall, adjusting agar–starch ratios produced distinct combinations of mechanical, thermal, and physical properties, with the 3:1 ratio offering the best balance of strength and water resistance. All formulations showed measurable biodegradation under water, UV, and soil conditions, indicating environmental degradability. Full article

Proton exchange membrane fuel cells (PEMFCs) are among the most promising clean energy conversion technologies, offering high efficiency and zero emissions. However, their large-scale commercialisation is limited by the high cost and environmental impact of conventional perfluorosulfonic acid membranes such as Nafion. In recent years, increasing attention has been directed toward biopolymer-based membranes as sustainable, low-cost, and biodegradable alternatives. This review provides a comprehensive overview of recent advances in the development and modification of biopolymer membranes, including polysaccharide-based materials such as chitosan, cellulose, gellan gum, sodium alginate, and starch, as well as protein-based materials such as keratin and collagen. Various modification strategies, including sulfonation, phosphorylation, cross-linking, and incorporation of inorganic or hybrid fillers, are analysed for their impact on key parameters, including proton conductivity, methanol permeability, and power density. Comparative data indicate that several modified biopolymer membranes achieve proton conductivities of 50 mS/cm or higher. However, higher conductivity values are generally reported for membranes primarily composed of synthetic polymers, where the biopolymer is incorporated only as an additive. In addition, some biopolymer-based membranes exhibit significantly lower methanol permeability than Nafion. The lowest reported value among the membranes discussed in this article is 0.98 × 10⁻¹⁶, representing the best-performing biopolymer membrane in terms of methanol permeability alone. Although many biopolymer membranes demonstrate relatively poor performance in single PEMFC tests, several have achieved power densities comparable to Nafion, while simultaneously offering improved environmental compatibility and sustainability. Finally, current challenges and future directions are discussed, emphasising the potential of these renewable materials to advance PEMFC technology toward more sustainable and economically viable energy systems. Full article

As a sustainable alternative to petroleum-based plastics, psyllium gum, a natural hydrocolloid from Plantago ovata seeds, is reviewed for its application in packaging. This review focuses on the material properties of psyllium gum, including its film-forming capacity, water-binding capacity of 12–15 g/g, and rheological behavior (consistency index K = 10–50 Pa·sⁿ, flow behavior index n = 0.3–0.6), which are critical for packaging applications. We discuss how its performance can be enhanced through interactions with plasticizers, cross-linking agents, and blending with other biopolymers (e.g., polyvinyl alcohol and starch), as well as through nanocomposite reinforcement, to improve mechanical strength (tensile strength 5–15 MPa in native films; up to 48 MPa in thermoplastic starch composites), and barrier properties (e.g., oxygen permeability < 0.001 g/m² s). The review also provides a comparative analysis of psyllium-based films with other polysaccharide films and discusses the environmental benefits, such as a lower carbon footprint (GWP ≈ 1.2 kg CO₂-eq/kg) compared to PET (≈3.0 kg CO₂-eq/kg). Key challenges, including moisture sensitivity (equilibrium moisture content ~25% at 75% RH), raw material molecular-weight variability (±20%), and scalability, are outlined, along with future research directions, such as enzymatic extraction and the development of water-resistant, compostable formulations aimed at advancing psyllium gum toward viable next-generation sustainable food packaging materials. Full article

Two hemostatic bionanocomposite dressings were developed using natural, semi-natural (or semi-synthetic) and synthetic polymers. The first system consisted of chitosan (CS), polyvinyl alcohol (PVA), and carboxymethyl cellulose (CMC) (CS/PVA/CMC), while the second was based on CS, PVA, and starch (SR) (CS/PVA/SR). Zinc oxide (ZnO) nanoparticles and bicyclic monoterpene camphor (CP) ketone were incorporated as bioactive agents in order to enhance antimicrobial and hemostatic performance. FTIR spectroscopy confirmed the successful solvent casting synthesis of the dressings and the interactions between the biopolymers and additives. XRD analysis indicated a predominantly amorphous structure, while SEM images and EDS analysis revealed uniform dispersion of ZnO particles within the polymer matrices without aggregation. Furthermore, the CS/PVA/CMC-1ZnO/CP sample exhibited a water sorption of 12,666 ± 126%, while CS/PVA/SR-1ZnO/CP reached 7013 ± 215%. ZnO incorporation also improved mechanical performance, with CS/PVA/SR-2ZnO/CP displaying the highest tensile strength (39.18 ± 0.2 MPa) and elongation at break (9.54 ± 1.04%). ZnO incorporation also led to a concentration-dependent increase in antibacterial activity, with SR-based dressings achieving near-complete bacterial reduction at higher ZnO loadings. All the dressings demonstrated good biocompatibility, while CS/PVA/SR-1ZnOCP showed the fastest clotting time (420 s ± 40), highlighting its potential for hemostatic applications. Full article

Hydrogels constructed from natural biomacromolecules with multifunctional properties, such as improved mechanical strength, ionic stability, biocompatibility, and ionic conductivity, are highly desirable for advanced food and biomedical applications, yet remain challenging to design. Although alginate is one of the most widely used hydrogel-forming polysaccharides due to its biocompatibility and gelation ability, its intrinsic limitations often hinder the development of hydrogels with fully optimized performance. This review provides a systematic comparison of alginate-based composite hydrogels formed with complementary biopolymers, including whey proteins, gelatin, pectin, starch, and chitosan, focusing on their synergistic effects on structural, mechanical, and functional properties. Recent studies are critically analyzed to elucidate how polymer–polymer interactions influence gel network formation, environmental ionic stability, and encapsulation performance. Particular attention is given to fabrication strategies and formulation parameters that enhance the immobilization and controlled release of probiotics, vitamins, polyphenols, and other bioactive compounds. By integrating current knowledge on structure–function relationships and processing approaches, this review offers practical design guidelines for the development of multifunctional alginate-based hydrogel systems for applications in functional foods and nutraceutical delivery. Full article

Hydrogels have emerged as promising functional materials for improving water management and nutrient delivery in agriculture, particularly under conditions of increasing water scarcity and declining soil fertility. However, most commercially available superabsorbent hydrogels are based on petroleum-derived polymers, raising concerns regarding their persistence in soils, potential microplastic formation and long-term environmental impact. In response, significant research efforts are being directed toward the development of biodegradable hydrogels derived from renewable biopolymers. This review provides a critical overview of recent advances in hydrogel systems designed for agricultural applications, with a particular focus on biopolymer-based materials. First, the current landscape of hydrogel technologies used as soil conditioners and controlled-release systems for agrochemicals is contextualized, highlighting the limitations of conventional synthetic hydrogels. Subsequently, the main classes of natural polymers explored for hydrogel fabrication, including polysaccharides (e.g., chitosan, alginate, cellulose and starch) and proteins (e.g., gelatin, keratin and soy protein), are analyzed in terms of raw material sources, gelation mechanisms and structure–property relationships. Their performance in key agricultural functions, such as water retention, controlled nutrient release, soil conditioning and enhancement of plant growth, is also discussed. Finally, the review identifies major challenges that currently hinder large-scale implementation, including mechanical stability, degradation behavior in complex soil environments, nutrient release control and economic scalability. By integrating recent progress and outlining emerging research directions, this work aims to support the rational design of next-generation biodegradable hydrogels capable of contributing to sustainable agriculture and circular bioeconomy strategies. Full article

pH-responsive indicator films for intelligent food packaging applications are based on the embedding of a natural or synthetic dye in a polymeric substrate, preferably biobased and biodegradable. Although natural colorants like anthocyanins were extensively investigated in this respect, nature-inspired synthetic flavylium compounds could represent an alternative based on their higher stability. In this work, five novel synthetic 4′-aminoflavylium derivatives with different substitution patterns in the benzopyrylium core (compounds 1–5) were synthesized and characterized. Polyvinyl alcohol (PVA), as well as chitosan–PVA and chitosan–starch blends, were used to prepare pH-responsive indicator films having inserted each of the synthesized flavylium dyes or a natural onion peel extract. The PVA films with compounds 1 and 3, and the PVA–chitosan film with compound 1, exhibited antioxidant activity, highlighting their potential for active packaging applications. All indicator films showed pH responsiveness in the range of 2 to 12 and were subsequently tested in contact with the packaging atmosphere or in direct contact with pork and fish meat, at different temperatures (4 °C, 20 °C, and 40 °C) for 24 h to assess their colorimetric response to progressive spoilage. Although the differences were small, the films with the 7-hydroxy-4′-aminoflavylium derivative exhibited the earliest and most intense color change during storage of meat, starting from direct contact at 4 °C for 24 h, being able to identify the initial stages of meat spoilage, while the performance of the dihydroxy-substituted derivative was attenuated by incorporation in polymer matrices. This behavior was comparable to that of onion peel extract, but the synthetic flavylium derivative was more stable. The results can provide new opportunities for intelligent food packaging applications using biopolymer indicator films with 4′-aminoflavylium derivatives. Full article

The environmental impact of conventional plastics has driven a shift toward biobased food packaging, shaped by consumer expectations, market trends, and regulatory policies within the European Union (EU). Despite extensive research on biopolymers such as starch, cellulose, chitosan, and polylactic acid (PLA), their use in commercial food packaging remains limited. A major challenge identified in the literature is the evaluation of biopolymer performance, in which environmental benefits are often considered independently of mechanical, barrier, and economic factors. This review addresses this gap by critically exploring the functional performance of biopolymers regarding their chemical structure and processing methods, with particular emphasis on the role of bioactive compounds in enhancing these materials’ properties. Although several biopolymers can achieve tensile strength values comparable to conventional petroleum-based plastics, their higher water vapor transmission rates remain an unsolved barrier to scalability. These limitations, together with challenges related to mechanical performance and production costs, are discussed to clarify their impact on industrial feasibility and to identify priorities for future research supporting scalable, cost-effective, and regulatory-compliant food packaging solutions. Full article

Biopolymer-based encapsulation represents an effective strategy to enhance probiotic stability and targeted gastrointestinal delivery. In this study, gel capsules composed of sodium alginate (SA) and wheat starch (ST) were developed via extrusion to encapsulate Lacticaseibacillus rhamnosus (L. rhamnosus) and Bacillus clausii (B. clausii), aiming to improve probiotic viability and controlled release. Capsule morphology, color, swelling behavior, encapsulation efficiency, and probiotic survival under simulated gastrointestinal conditions were systematically evaluated as a function of polymer ratio and probiotic loading. Capsule diameters ranged from 236.6 to 279.17 μm and were primarily governed by the SA-ST ratio, with higher ST content yielding smaller, more compact structures. Encapsulation efficiency varied between 71.2% and 96.7%, reaching maximal values in formulations with balanced SA:ST ratios (1:1) and higher probiotic loads. All formulations maintained high cell viability (>96%) following encapsulation. In vitro digestion studies demonstrated that SA-ST capsules significantly enhanced probiotic survival in simulated gastric and intestinal fluids, with the highest cumulative survival observed in ST-rich matrices containing 20% probiotic load. Swelling analyses revealed that ST incorporation promoted controlled hydration and matrix relaxation without compromising structural integrity, supporting sustained release behavior. Overall, the SA-ST biopolymer system provides a simple, scalable, and cost-effective platform for co-encapsulation of L. rhamnosus and B. clausii, offering synergistic protection, high encapsulation efficiency, and improved gastrointestinal stability, with promising applications in functional foods and pharmaceutical formulations. Full article

Biomasses from agro-industrial practices in the Amazon have generated significant inputs in the last decade for the development of projects and the extension of more sustainable production chains, based on the results of research on both laboratory and pilot scales, and from the rapid expansion in industrial scaling. The rise in the use of biomass includes the use of raw materials from so-called superfruits, notable examples of which include açaí (Euterpe oleracea Mart.), Brazil nut (Bertholletia excelsa HBK), pupunha (Bactris gasipaes Kunth), tucumã (Astrocaryum aculeatum) and buriti (Mauritia flexuosa). All of these are of great importance to the trade balance of the Amazon region, contributing significantly to the import of products and by-products from Brazil. In view of the above, this research aims to present the nutritional, functional and technological properties of these biomasses as a contribution to industrial innovation in the use of isolated constituents in various segments of the food, pharmaceutical, dermocosmetic and packaging industries. The data show that research into the protein, fibrous and starch-based biopolymers contained in these biomasses has been guided and deepened, with an emphasis on investigations in isolation and on applications of bioactive compounds and starches and fibers in the development of films and packaging with good resistance properties and high environmental biodegradability, these being economically viable as food coatings, acting in synergy with the application of technologies and the increase in the sustainable circular bioeconomy in the Amazon, combining techno-economic and environmental development in the most diverse industrial sectors. Full article

This study investigated the characterization and application of organoclay formulations in a chemoautotrophic biofloc system. Organoclays were produced using the calcination method and bentonite, chitosan, corn, and tapioca starches as ingredients. Thermogravimetric analysis confirmed the high thermal stability of bentonite, whereas biopolymers (tapioca, chitosan, and corn starch) exhibited greater thermal sensitivity and a lower residual mass. Scanning electron microscopy revealed that organoclays had increased porosity (4–21 µm) compared to bentonite, while energy-dispersive spectroscopy confirmed the retention of key chemical elements. X-ray diffraction and Fourier-transform infrared spectroscopy indicated structural modifications due to thermal processing. In aqueous conditions, bentonite and organoclays disaggregated into particles with sizes between 0.76 and 1.24 μm. Based on these physicochemical properties, three formulations were selected for nitrification trials due to their stability in water, O1 (bentonite + tapioca), O2 (bentonite + tapioca + chitosan), and O6 (bentonite + corn starch), along with a 100% bentonite treatment and a control group (C) supplemented with inorganic salts and artificial Needlona^® substrates. All treatments achieved full nitrification within 37 days, with O1 exhibiting the best performance by maintaining ammonia and nitrite levels within safe thresholds. These findings suggest that organoclays, particularly O1, can enhance nitrification stability, providing a promising strategy for water quality management in intensive aquaculture systems. Full article

Biopolymer adhesives are moving toward frontline use in medicine and manufacturing as the limitations in some petrochemical systems, including cytotoxicity, challenges in wet adhesion for specific families of synthetic resins and formaldehyde emissions associated with amino-formaldehyde materials are becoming increasingly difficult to accept. This review integrates mechanisms, material classes and quantitative performance across biopolymer-based adhesives. We focus on architectures that combine permanent covalent anchoring with reversible, energy-dissipating bonds and on how functional group density, crosslink density, microstructure and additives act as design knobs for wet performance, durability and degradation. Across biomedical applications, chitosan, alginate, gelatin and related hydrogels achieve wet lap-shear strengths on the order of tens of kilopascals, cut liver-bleeding times by roughly half, provide strong antibacterial activity and close diabetic wounds by about 92 percent by day 14. Thermoresponsive alginate–gelatin sealants exceed clinically relevant burst pressures and microneedle patches withstand more than 120 mmHg while sealing arteries in under a minute. In industrial settings, dialdehyde-based starch resins deliver 0.83 to 1.05 MPa dry shear and maintain strength after water immersion while meeting stringent emission classes, and silane-modified nanocellulose in urea–formaldehyde markedly reduces free formaldehyde without sacrificing the internal bond. We conclude by identifying priorities for standardized wet testing, and lifetime matching of strength and degradation that can support large-scale clinical and industrial translation. Full article