An Overview of the Alternative Use of Seaweeds to Produce Safe and Sustainable Bio-Packaging

Seaweeds as a major source of dietary microplastics exposure in East Asia

Microplastics (MPs) occurrence in marine ecosystems is well known, but their accumulation in seaweeds and subsequent human exposure remain understudied. This research quantifies MPs presence in two commonly consumed seaweeds, kelp (Saccharina japonica) and nori (Pyropia yezoensis), in East Asia, revealing widespread contamination dominated by microfibers (<500 μm). Based on dietary patterns, human uptake through seaweed consumption was estimated and quantified. Notably, Chinese people consume an estimated 17,034 MPs/person/year through seaweed consumption, representing 13.1% of their total annual MPs intake. This seaweeds-derived exposure surpasses all other dietary sources, contributing up to 45.5% of overall MPs intake. The highest intake was in South Korea, followed by North Korea, China, and Japan. This research identifies seaweeds as a major, previously overlooked route of dietary MPs exposure. These findings are crucial for comprehensive risk assessments of seaweed consumption and the development of mitigation strategies, particularly for populations in East Asian countries.

Seaweed-based biopolymers for food packaging: A sustainable approach for a cleaner tomorrow

With the increasing environmental and health consequences of uncontrolled plastic use, the scientific community is progressively gravitating toward biodegradable and ecofriendly packaging alternatives. Seaweed polysaccharides have attracted attention recently because of their biodegradability, nontoxicity, antioxidant properties, and superior film-forming ability. However, it has some limitations for packaging applications, such as low tensile strength, water solubility, and only modest antimicrobial properties. The incorporation of biopolymers, nanoparticles, or organic active ingredients enhances these characteristics. This review encapsulates the contemporary research landscape pivoting around the role of seaweed polysaccharides in the development of bioplastics, active packaging solutions, edible films, and protective coatings. A meticulous collation of existing literature dissects the myriad food application avenues for these marine biopolymers, emphasizing their multifaceted physical, mechanical, thermal, and functional attributes, including antimicrobial and antioxidant. A key facet of this review spotlights environmental ramifications by focusing on their biodegradability, reinforcing their potential as a beacon of sustainable innovation. This article delves into the prevalent challenges that stymie large-scale adoption and commercialization of seaweed-centric packaging, offering a comprehensive perspective on this burgeoning domain.

Effect of Padina gymnospora biowaste inclusion on in vitro methane production, feed fermentation, and microbial diversity

In vitro studies were undertaken aiming to study the methane (CH4) mitigation potential of biowaste (BW) of Padina gymnospora at the graded inclusion of 0% (C), 2% (A2), 5% (A5), and 10% (A10) of the diet composed of straw and concentrate in 40:60 ratio. The chemical composition analysis revealed that the BW contained higher crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ether extract (EE) than the PF (fresh seaweed, P. gymnospora). The concentration of cinnamic acid, sinapic acid, kaempferol, fisetin p-coumaric acid, ellagic acid, and luteolin in BW was 1.5-6-folds less than the PF. Inclusion of BW decreased (P < 0.0001) CH4 production by 34%, 38%, and 45% in A2, A5, and A10 treatments, respectively. A decrease (P < 0.0001) of 7.5%-8% in dry matter (DM) and organic matter (OM) digestibility was also recorded with the BW supplementation. The BW inclusion also decreased the numbers of total (P = 0.007), Entodinomorphs (P = 0.011), and Holotrichs (P = 0.004) protozoa. Metagenome data revealed the dominance of Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria, and Fibrobacter microbial phyla. At the phylum level, Euryarchaeota dominated the archaeal community, whereas Methanobrevibacter was most abundant at the genus level. It can be concluded that the inclusion of BW in straw and concentrate based diet by affecting rumen fermentation, protozoal numbers, and compositional shift in the archaeal community significantly decreased CH4 production. Utilization of biowaste of P. gymnospora as a CH4 mitigating agent will ensure its efficient utilization rather than dumping, which shall cause environmental pollution and health hazards.

Seaweed as Basis of Eco-Sustainable Plastic Materials: Focus on Alginate

Seaweed, a diverse and abundant marine resource, holds promise as a renewable feedstock for bioplastics due to its polysaccharide-rich composition. This review explores different methods for extracting and processing seaweed polysaccharides, focusing on the production of alginate plastic materials. Seaweed emerges as a promising solution, due to its abundance, minimal environmental impact, and diverse industrial applications, such as feed and food, plant and soil nutrition, nutraceutical hydrocolloids, personal care, and bioplastics. Various manufacturing techniques, such as solvent casting, injection moulding, and extrusion, are discussed for producing seaweed-based bioplastics. Alginate, obtained mainly from brown seaweed, is particularly known for its gel-forming properties and presents versatile applications in many sectors (food, pharmaceutical, agriculture). This review further examines the current state of the bioplastics market, highlighting the growing demand for sustainable alternatives to conventional plastics. The integration of seaweed-derived bioplastics into mainstream markets presents opportunities for reducing plastic pollution and promoting sustainability in material production.

Algal-based bioplastics: global trends in applied research, technologies, and commercialization

The excessive global demand for plastic materials has resulted in severe plastic waste pollution. Conventional plastics derived from non-renewable fossil fuels are non-biodegradable, leading to significant environmental problems. Algal-based bioplastics represent a more viable, renewable, and sustainable alternative to conventional plastics. They have identical properties and characteristics as conventional plastics while being naturally biodegradable. The potential of the algal biomass value chain has already been well-established by researchers. Here, we review the novel insights on research, technology, and commercialization trends of algal-based bioplastics, encompassing macroalgae and green microalgae/cyanobacteria. Data showed that within the last decade, there has been substantial interest in utilizing microalgae for biopolymer production, with more focus on using cyanobacterial species compared to green algae. Moreover, most of the research conducted has largely focused on the production of PHA or its co-polymers. Since 2011, there have been a total of 55 patents published related to algal-based bioplastics production. To date, ~ 81 entities worldwide (commercial and private businesses) produce bioplastics from algae. Overall results of this study emphasized that even with the economic and social challenges, algae possess a substantial potential for the sustainable development of bioplastics while also addressing the UN's SDGs.

Properties of biopolymer blends based on Rugulopteryx okamurae and hydrophobic polycaprolactone (PCL) and hydrophilic acylated soy protein isolated (SPIa)

The present study explored the utilization of Rugulopteryx okamurae (RO), an invasive brown seaweed, as a renewable raw material for plastic materials based on biopolymer blends. The goal of this study was to improve the previously observed poor mechanical properties of materials based on single biopolymer RO. To enhance these properties, two polymers with distinct hydrophobicities were incorporated into the formulation of different blends: hydrophobic polycaprolactone (PCL) and hydrophilic acylated soy protein isolate (SPIa). SPIa was derived from soy protein through a chemical modification process, introducing hydrophilic carboxyl groups. The addition of PCL significantly strengthened the blend, increasing the storage modulus (E'1 Hz) from ~ 110 to ~ 250 MPa. Conversely, SPIa incorporation resulted in softening, with E' values around 40 MPa. Both additives enhanced deformability proportionally to their concentrations, with SPIa exhibiting notably higher deformability, reaching a maximum deformation of ~ 23% for a RO/SPIa ratio of 25/75. In summary, the study demonstrates the feasibility of producing environmentally friendly blend materials based on RO, tailored for specific applications by incorporating suitable additives into the formulation. Therefore, PCL is recommended for applications susceptible to moisture effects, such as packaging, while SPIa is suggested for highly absorbent applications such as personal care or horticulture.

Recent Progress of Carrageenan-Based Composite Films in Active and Intelligent Food Packaging Applications

Recently, as concerns about petrochemical-derived polymers increase, interest in biopolymer-based materials is increasing. Undoubtedly, biopolymers are a better alternative to solve the problem of synthetic polymer-based plastics for packaging purposes. There are various types of biopolymers in nature, and mostly polysaccharides are used in this regard. Carrageenan is a hydrophilic polysaccharide extracted from red algae and has recently attracted great interest in the development of food packaging films. Carrageenan is known for its excellent film-forming properties, high compatibility and good carrier properties. Carrageenan is readily available and low cost, making it a good candidate as a polymer matrix base material for active and intelligent food packaging films. The carrageenan-based packaging film lacks mechanical, barrier, and functional properties. Thus, the physical and functional properties of carrageenan-based films can be enhanced by blending this biopolymer with functional compounds and nanofillers. Various types of bioactive ingredients, such as nanoparticles, natural extracts, colorants, and essential oils, have been incorporated into the carrageenan-based film. Carrageenan-based functional packaging film was found to be useful for extending the shelf life of packaged foods and tracking spoilage. Recently, there has been plenty of research work published on the potential of carrageenan-based packaging film. Therefore, this review discusses recent advances in carrageenan-based films for applications in food packaging. The preparation and properties of carrageenan-based packaging films were discussed, as well as their application in real-time food packaging. The latest discussion on the potential of carrageenan as an alternative to traditionally used synthetic plastics may be helpful for further research in this field.

A review of microalgae biofilm as an eco-friendly approach to bioplastics, promoting environmental sustainability

In this comprehensive review, we delve into the challenges hindering the large-scale production of microalgae-based bioplastics, primarily focusing on economic feasibility and bioplastic quality. To address these issues, we explore the potential of microalgae biofilm cultivation as a sustainable and highly viable approach for bioplastic production. We present a proposed method for producing bioplastics using microalgae biofilm and evaluate its environmental impact using various tools such as life cycle analysis (LCA), ecological footprint analysis, resource flow analysis, and resource accounting. While pilot-scale and large-scale LCA data are limited, we utilize alternative indicators such as energy efficiency, carbon footprint, materials management, and community acceptance to predict the environmental implications of commercializing microalgae biofilm-based bioplastics. The findings of this study indicate that utilizing microalgae biofilm for bioplastic production offers significant environmental sustainability benefits. The system exhibits low energy requirements and a minimal carbon footprint. Moreover, it has the potential to address the issue of wastewater by utilizing it as a carbon source, thereby mitigating associated problems. However, it is important to acknowledge certain limitations associated with the method proposed in this review. Further research is needed to explore and engineer precise techniques for manipulating microalgae biofilm structure to optimize the accumulation of desired metabolites. This could involve employing chemical triggers, metabolic engineering, and genetic engineering to achieve the intended goals. In conclusion, this review highlights the potential of microalgae biofilm as a viable and sustainable solution for bioplastic production. While acknowledging the advantages, it also emphasizes the need for continued synthetic studies to enhance the efficiency and reliability of this approach. By addressing the identified drawbacks and maximizing the utilization of advanced techniques, we can further harness the potential of microalgae biofilm in contributing to a more environmentally friendly and economically feasible bioplastic industry.

Synthesis and Characterization of a New Alginate/Carrageenan Crosslinked Biopolymer and Study of the Antibacterial, Antioxidant, and Anticancer Performance of Its Mn(II), Fe(III), Ni(II), and Cu(II) Polymeric Complexes

Natural polysaccharides are essential to a wide range of fields, including medicine, food, and cosmetics, for their various physiochemical and biological properties. However, they still have adverse effects limiting their further applications. Consequently, possible structural modifications should be carried out on the polysaccharides for their valorization. Recently, polysaccharides complexed with metal ions have been reported to enhance their bioactivities. In this paper, we synthesized a new crosslinked biopolymer based on sodium alginate (AG) and carrageenan (CAR) polysaccharides. The biopolymer was then exploited to form complexes with different metal salts including MnCl₂·4H₂O, FeCl₃·6H₂O, NiCl₂·6H₂O, and CuCl₂·2H₂O. The four polymeric complexes were characterized by Fourier-transform infrared spectroscopy (FT-IR), elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), magnetic susceptibility, molar conductivity methods, and thermogravimetric analysis. The X-ray crystal structure of the Mn(II) complex is tetrahedral and belongs to the monoclinic crystal system with the space group P121/n1. The Fe(III) complex is octahedral and crystal data fit with the cubic crystal system with the space group Pm-3m. The Ni(II) complex is tetrahedral and crystal data correspond to the cubic crystal arrangement with the space group Pm-3m. The data estimated for the Cu(II) polymeric complex revealed that it is tetrahedral and belongs to the cubic system with the space group Fm-3m. The antibacterial study showed significant activity of all the complexes against both Gram-positive bacteria (Staphylococcus aureus and Micrococcus luteus) and Gram-negative (Escherichia coli and Salmonella typhimurium) pathogenic strains. Similarly, the various complexes revealed an antifungal activity against Candida albicans. The Cu(II) polymeric complex recorded a higher antimicrobial activity with an inhibitory zone reaching 4.5 cm against Staphylococcus aureus bacteria and the best antifungal effect of 4 cm. Furthermore, higher antioxidant values of the four complexes were obtained with DPPH scavenging activity varying from 73 to 94%. The two more biologically effective complexes were then selected for the viability cell assessments and in vitro anticancer assays. The polymeric complexes revealed excellent cytocompatibility with normal human breast epithelial cells (MCF10A) and a high anticancer potential with human breast cancer cells (MCF-7) which increase significantly in a dose-dependent manner.

Cinnamon-Nanoparticle-Loaded Macroalgal Nanocomposite Film for Antibacterial Food Packaging Applications

In addition to environmental concerns, the presence of microorganisms in plastic food packaging can be hazardous to human health. In this work, cinnamon nanoparticles incorporated with red seaweed (Kappaphycus alvarezii) biopolymer films were fabricated using a solvent casting method. Cinnamon was used as a filler to enhance the properties of the films at different concentrations (1, 3, 5, and 7% w/w) by incorporating it into the matrix network. The physico-chemical, thermal, mechanical, and antimicrobial properties of the cinnamon biopolymer films were obtained using dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FT-IR), water contact angle (WCA) measurement, thermogravimetric analysis (TGA), mechanical testing, and antimicrobial testing, respectively. The results showed that the addition of cinnamon nanoparticles to the film improved the morphological, mechanical, thermal, wettability, and antibacterial properties of the nanocomposite films. The cinnamon particles were successfully reduced to nano-sized particles with an average diameter between 1 nm and 100 nm. The hydrophobicity of the film increased as the concentration of cinnamon nanoparticles incorporated into the seaweed matrix increased. The tensile and thermal properties of the cinnamon seaweed biopolymer film were significantly improved with the presence of cinnamon nanoparticles. The biopolymer films exhibited good inhibitory activity at 7% cinnamon nanoparticles against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Salmonella bacteria with inhibition zone diameters of 11.39, 10.27, and 12.46 mm, indicating the effective antimicrobial activity of the biopolymer film. The functional properties of the fabricated biopolymer film were enhanced with the addition of cinnamon nanoparticles.

A Concise Review on the Potential Applications of Rugulopteryx okamurae Macroalgae

The brown macroalgae of the species Rugulopteryx okamurae has reached European waters and the Strait of Gibraltar as an invasive species. The proliferation and colonization of the species in subtidal and intertidal zones of these regions imposes significant threats to local ecosystems and additionally represents a significant socioeconomic burden related to the large amounts of biomass accumulated as waste. As a way to minimize the effects caused by the accumulation of algae biomass, investigations have been made to employ this biomass as a raw material in value-added products or technologies. The present review explores the potential uses of R. okamurae, focusing on its impact for biogas production, composting, bioplastic and pharmaceutical purposes, with potential anti-inflammatory, antibacterial and α-glucosity inhibitory activities being highlighted. Overall, this species appears to present many attributes, with remarkable potential for uses in several fields of research and in various industries.

Seaweed for climate mitigation, wastewater treatment, bioenergy, bioplastic, biochar, food, pharmaceuticals, and cosmetics: a review

The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.