Biodegradable mulch films are essential for reducing plastic pollution in agriculture; however, current production methods often rely on complex and costly chemical processes. This study presents an innovative, ecofriendly approach to developing fully biodegradable mulch films using untreated vegetable stalks and sodium alginate through a simple blending method. By eliminating the need for pretreatment, this process significantly reduces energy consumption and maximizes agricultural waste utilization. The optimized film formulation (30 % vegetable stalk, 3 % solution, 40 % glycerin) demonstrated excellent mechanical and barrier properties, including tensile strength (6.8 MPa), elongation at break (29 %), water vapor permeability (1.88 x 10-12 g & sdot;cm-1 & sdot;Pa-1 & sdot;s-1), and UV-blocking efficiency (98.5 %), and thermal insulation and moisture retention properties. Rheological analysis showed that the addition of vegetable stalks impacted the film-forming solution's properties, enhancing processing and application performance. Additionally, the films facilitated seed germination and maintained functionality on the surface of moist soil, while rapidly degrading when buried in moist soil. Life Cycle Assessment confirmed that the biodegradable films significantly reduce environmental impacts, supporting their potential for widespread adoption in sustainable agricultural practices. This study provides a scalable and cost-effective strategy for converting agricultural residues into high-performance biodegradable films, addressing the need for sustainable solutions in agriculture and environmental protection.
This study investigated the conversion of cellulose from rice husk (RH) and straw (RS), two types of agricultural waste, into Carboxymethyl cellulose (CMC). Cellulose was extracted using KOH and NaOH, hydrolyzed, and bleached to increase purity and fineness. The cellulose synthesis yielded a higher net CMC content for RH-CMC (84.8%) than for RS-CMC (57.7%). Due to smaller particle sizes, RH-CMC exhibited lower NaCl content (0.77%) and higher purity. FT-IR analysis confirmed similar functional groups to commercial CMC, while XRD analysis presented a more amorphous structure and a higher degree of carboxymethylation. A biodegradable film preparation of starch-based CMC using citric acid as a crosslinking agent shows food packaging properties. The biodegradable film demonstrated good swelling, water solubility, and moisture content, with desirable mechanical properties, maximum load (6.54 N), tensile strength (670.52 kN/m2), elongation at break (13.3%), and elastic modulus (2679 kN/m2), indicating durability and flexibility. The RH-CMC film showed better chemical and mechanical properties and complete biodegradability in soil within ten days. Applying the biodegradable film for tomato preservation showed that wrapping with the film reduced weight loss more efficiently than dip coating. The additional highlight of the work was a consumer survey in Thailand that revealed low awareness but significant interest in switching to alternative uses, indicating commercial potential for eco-friendly packaging choices and market opportunities for sustainable materials.
The growing accumulation of agricultural waste, particularly groundnut shells, presents significant environmental concerns due to methane emissions and greenhouse gas release from crop residue burning. Groundnut shell powder, a biodegradable byproduct, offers potential as a raw material for bio-nanocomposite films. This study focuses on the development of biodegradable packaging films from groundnut shell powder, evaluating their physicochemical and mechanical properties while optimizing process parameters. Experiments were conducted to optimize the process parameters, viz., shaker time (6, 12, and 18 h), shaker speed (160, 180, and 240 rpm), and concentration of laccase enzyme (80, 100, and 120 mg) to leach out maximum lignin content in short duration. Further, to stop enzymatic reaction, drying time, drying temperature, and storage condition (dark or light) were optimized to minimize the time of operation, maximize cellulose, and minimize lignin content for isolation of cellulose microfibers from peanut shell powder. The biodegradable film from groundnut shell powder was developed by solution casting method. The three types of films, viz., agar powder-based (AG), mixture of agar powder and peanut shell powder (PSP), and mixture of agar powder and cellulose microfiber (CMF), were developed at optimized conditions. The maximum thickness was achieved by the cellulose microfiber-based film. The transmittance value of agar film was lesser than that of CMF film and PSP. The CMF film's water solubility and tensile strength was observed highest in comparison to that of the other two films. CMF and PSP films had a higher opacity value than agar films. Due to the presence of lignin, it was found that PSP loses less weight than CMF film during the soil burial degradation test. Therefore, the findings suggested that CMF film possesses not only improved biodegradability but also superior physical and mechanical properties, which may be suitable for use as a food packaging material.
This research investigated the production of biodegradable plastic films made from a blend of carrageenan and corn starch biopolymers. The procedure included producing bioplastic resin pellets using a single screw extrusion at a 110 degrees C temperature, followed by hot compression at a temperature of 160 degrees C to form a biodegradable plastic film. The project aimed to develop a continuous biodegradable plastic production method, particularly made from carrageenan, which is more adaptable for commercial-scale production. The carrageenan/corn starch films were prepared with various compositions, ranging from formulations dominated by carrageenan (56:14% w/w) to those dominated by corn starch (14:56% w/w), with the addition of a constant amount of glycerol (30% w/w) as a plasticizer. After the films were obtained, each of the samples was evaluated for their physico-mechanical properties, chemical structure, water sensitivity, and soil biodegradability. In general, an increase in corn starch content within the film matrix led to an enhancement of the overall properties of the resulting film. The film with the highest corn starch content exhibited tensile strength and elongation at break values that were 49% and 163% higher, respectively, compared to the film with the lowest corn starch content. Additionally, these samples demonstrated improved thermal stability, with a 12% increase in the thermal decomposition temperature, and enhanced barrier properties, as evidenced by a 6% reduction in water vapor permeability and a 72% decrease in water uptake. This is mainly due to the inherent molecular structure of corn starch, particularly due to its long straight-glucose chains. On the other hand, carrageenan increased the biodegradability rate of the films. These findings demonstrate the potential of carrageenan/corn starch blends as promising candidates for future packaging materials.
Unlike many biopolymers, alpha-1,3-glucan (alpha-1,3-GLU) is water-insoluble, making it a promising candidate for the production of moisture-resistant films with applications in biodegradable packaging, biomedicine, and cosmetics. This study aimed to characterize the structural, physicochemical (water affinity, optical, mechanical), and biodegradation properties of a film made from alpha-1,3-GLU extracted from Laetiporus sulphureus. The film was fabricated through alkaline dissolution, casting, drying, washing to remove residual NaOH, and re-plasticization with a glycerol solution. FTIR and Raman spectroscopy confirmed the polysaccharide nature of the film, with predominant alpha-glycosidic linkages. The film exhibited a semi-crystalline structure and high opacity due to surface roughness resulting from polymer coagulation. Owing to re-plasticization, the film showed a high moisture content (similar to 47%), high water solubility (81.95% after 24 h), and weak mechanical properties (tensile strength = 1.28 MPa, elongation at break approximate to 10%). Its water vapor permeability (53.69 g mm m(-2) d(-1) kPa(-1)) was comparable to other glycerol-plasticized polysaccharide films reported in the literature. The film supported the adhesion of soil microorganisms and target bacteria and was susceptible to degradation by Trichoderma harzianum and endo- and exo-alpha-1,3-glucanases, indicating its biodegradability. The limitations in its mechanical strength and excessive hydration indicate the need for improvements in the composition and methods of producing alpha-1,3-GLU films.
This study explores the dual application of Karpuravalli banana plant waste for sustainable material development, focusing on the extraction of wax from banana shoots and the creation of biodegradable packaging films from banana peel powder. Two extraction methods, refluxing and Soxhlet, were used to obtain wax from mature and third leaf shoots, with Soxhlet yielding 4% wax and refluxing producing 2%. The wax exhibited properties similar to commercial natural waxes, with GC-MS analysis revealing a predominant C23 fatty acid. Biodegradable films were developed using banana peel powder, corn starch, glycerol, and wax as a moisture-resistant coating. The wax-coated films showed increased thickness and moisture resistance but decreased transparency and mechanical properties, such as tensile strength and elongation. Both film types achieved over 98% biodegradation in soil. This research highlights the potential of utilizing banana plant by-products for eco-friendly packaging solutions, demonstrating that while the wax improves moisture resistance, further optimization is needed to enhance mechanical performance, thus contributing to sustainable material development from agricultural waste.
Seaweeds are a rich source of various bioactive compounds and metabolites. In this study, sulfated polysaccharide, kappa-carrageenan has been isolated from red algae, Hypnea valentiae, and developed biodegradable film with the addition of plasticizers, sorbitol and polyethylene glycol (PEG 4000) at varying concentrations of carrageenan (1%, 5% and 7% Carr). The biodegradable film exhibited excellent mechanical properties with increasing carrageenan concentration. The 5% Carr film showed improved water barrier properties, high water contact angle (hydrophobicity), high tensile strength (11.38 MPa) and elongation at break (23.27%) which imparts rigidity and flexibility to the film. The results of FTIR and SEM images revealed that the plasticizers and polysaccharides have been blended properly. Since seaweeds are natural antioxidants the kappa-carrageenan based biodegradable films displayed strong radical scavenging activity. The 7% Carr film exhibited 86% of radical scavenging activity in ABTS assay and 5% Carr showed 80% of scavenging activity. The biodegradable films displayed efficient antibacterial activity against gram-negative bacteria, E. coli and gram-positive bacteria, B. subtilis. The developed films exhibited excellent biodegradability, the films samples degraded completely within 84 days of soil burial. The kappa-carrageenan based biodegradable film (5% Carr) from red algae, H. valentiae better serves as a versatile food packaging material.
The application of novel insect proteins as future food resources in the food field has attracted more and more attention. In this study, a biodegradable antibacterial food packaging material with beneficial mechanical properties was developed using Tenebrio molitor larvae protein (TMP), chitosan (CS) and propolis ethanol extract (PEE) as raw materials. PEE was uniformly dispersed in the film matrix and the composite films showed excellent homogeneity and compatibility. There are strong intermolecular hydrogen bond interactions between CS, TMP, and PEE in the films, which exhibit the structure characteristics of amorphous materials. Compared with CS/TMP film, the addition of 3 % PEE significantly enhanced the elongation at break (34.23 %), water vapor barrier property (22.94 %), thermal stability (45.84 %), surface hydrophobicity (20.25 %), and biodegradability of the composite film. The composite film has strong antioxidant and antimicrobial properties, which were enhanced with the increase of PEE content. These biodegradable films offer an eco-friendly end-of-life option when buried in soil. Composite films can effectively delay the spoilage of strawberries and extend the shelf life of strawberries. Biodegradable active packaging film developed with insect protein and chitosan can be used as a substitute for petroleum-based packaging materials, and has broad application prospects in the field of fruits preservation.
Nanotechnology offers an innovative application as an eco-friendly food packaging film fabricated along with a degradable active mixture (AM). The AM is an assortment of alloyed metal oxide nanoparticles (Ag-ZnO), citron powder (AA), and Curcuma peel powder (CPP). Alloyed nanoparticles (NPs) were observed to exhibit a hexagonal structure from the experimental X-ray diffraction. Compositional and morphological study of the NPs (22.69 nm) and AM (32 nm) was done using energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and zeta- potential was observed to be -14.7 mV, indicating the stability of NPs. The prepared film was observed to be more effective with antibacterial analysis against Escherichia coli, exhibiting 72% of inhibition and antioxidant activity with IC50: 51.56% using the 2,2 diphenyl-1-picrylhydrazyl (DPPH) assay. Film 1, Film 2, Film 3, and Film 4 were fabricated with the AM and observed to be perfectly encapsulated by PVA using XRD. FESEM images of the film exhibit the aggregation of NPs with biocomposites in perfect distribution. The mechanical properties such as Young's modulus, elongation at break, tensile strength, and ultimate tensile strength (UTS- 5.37 MPa) were experimented for the films. The degradation rate was observed to be 6.12% for film 1 using the soil burial method. The study emphasizes that NPs along with biocomposite upgrade the sustainability of the packaging film with improved mechanical and physicochemical properties. The synthesized film with biomaterials could be used as a green food package to store fruits, vegetables, and sweets in the food industry.
Conventional nondegradable packaging and mulch films, after reaching the end of their use, become a major source of waste and are primarily disposed of in landfills. Accumulation of non-degradable film residues in the soil leads to diminished soil fertility, reduced crop yield, and can potentially affect humans. Application of degradable films is still limited due to the high cost, poor mechanical, and gas barrier properties of current biobased synthetic polymers. In this respect, natural polysaccharides and proteins can offer potential solutions. Having versatile functional groups, three-dimensional network structures, biodegradability, ease of processing, and the potential for surface modifications make polysaccharides and proteins excellent candidates for quality films. Besides, their low-cost availability as industrial waste/byproducts makes them cost-effective alternatives. This review paper covers the performance properties, cost assessment, and in-depth analysis of macromolecular structures of some natural polysaccharides and proteins-based films that have great potential for packaging and mulch applications. Proper dissolution of biopolymers to improve molecular interactions and entanglement, and establishment of crosslinkages to form an ordered and cohesive polymeric structure can help to obtain films with good properties. Simple aqueous-based film formulation techniques and utilization of waste/byproducts can stimulate the adoption of affordable biobased films on a large-scale.