The limitations of traditional non-absorbable implants, such as high immune rejection rates and insufficient osteoinductive properties, have driven the search for alternative strategies to improve bone regeneration. This study explores the synthesis of nanosized β-carbonated hydroxyapatite (β-CHA) derived from eggshell waste and its coating onto 3D bioabsorbable poly (lactic acid) (PLA) textile scaffolds, fabricated using weft-knitting techniques for bone regeneration applications. The β-CHA integration within the scaffolds was analysed through Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), microscopic imaging, water contact angle measurements, pH monitoring, and alizarin red staining. Results confirmed that the precipitation method effectively produces β-CHA particles, achieving a stable pH range of 6.8 to 7, suitable for biological compatibility. The study further emphasizes the critical role of pore interconnectivity and macroporosity in scaffold design, validating knitting as a viable textile technique for creating tailored, structurally robust scaffolds. These findings highlight the potential of repurposing food waste, particularly eggshells, in combination with textile manufacturing to develop active scaffolds that support enhanced bone tissue engineering outcomes. 

Food-waste-derived bio-based materials offer both environmental and economic advantages. We utilised waste lemon peel as substrate to generate value-added materials from chitosan-rich fungal cell wall of Rhizopus delemar and purified cellulose from pre-treated solid residues. Nutrient from lemon peel was used for fungal cultivation and the cell wall was isolated from the obtained fungal biomass using mild alkali treatment. The fungal cell wall was used to develop a hydrogel through protonation of amino groups in chitosan by lactic acid addition. This hydrogel served as spinning dope to produce fungal monofilaments using dry gel spinning with a tensile strength of 85 MPa. Simultaneously, cellulose purified from pre-treated solid residues, converted to micro-nanocellulose suspension via mechanical fibrillation and underwent dry gel spinning to produce cellulose monofilaments with a tensile strength of 298 MPa. Cellulose fraction was analysed using XRD, FTIR, TGA, and elemental analyses. The micro- and nanoscale structures of fibrillated cellulose were verified by SEM and AFM. The findings of this study demonstrate a novel holistic valorisation approach for lemon peel waste as a resource for bio-based monofilaments, which could be used as alternatives to commercial fibres in textiles.

Despite being considered a premium material, leather poses both environmental and ethical issues. Thus, sustainable alternatives such as vegan leather are in high demand. Therefore, in this study, we aimed to produce vegan leather using vegetable tannins and fungi grown on bread waste. Fungal cultivation was carried out in a bubble column bioreactor using nutrients extracted from bread as substrate. To obtain tanned biomass, the biomass was subjected to vegetable tanning (using Tara, Myrobalan, Chestnut, and Indusol ATO tannins). A mild alkali treatment isolated the fibrous cell wall material from fungal biomass. Different composite sheets were prepared by wet-laying the tanned biomass and cell wall material and placing them in a multilayer arrangement. The composites were post-treated with glycerol and a bio-based binder to improve their mechanical properties. Myrobalan-tanned biomass composites after glycerol and bio-based binder post-treatments had the highest flexibility of 14.8% elongation at break, and Tara-tanned biomass composites had the highest tensile strength of 20.5 MPa. Ashby’s chart demonstrates the relationship between the sheets produced and natural leather. SEM was used to demonstrate the softer and smoother morphologies of the Chestnut and Indusol ATO-tanned composite sheets after post-treatment. Overall, this study presents multilayer fungal biocomposites as a promising vegan alternative leather.

Protein extraction from wheat bran is challenging due to its multi-layer and fiber-rich structure. Here, opening aleurone cells, via dry and wet milling, their combination and a novel ultrafine milling, and its effect on wheat bran's protein recovery using the alkaline solubilization/isoelectric precipitation and protein structure, functionality, and phytate content were investigated. Wet milling and ultrafine milling improved protein recovery and purity but only ultrafine milling reduced bran particle size to the aleurone cells and exposed their structure. Despite this, ultrafine milling did not significantly increase protein yield compared to wet milling, which partially opened the aleurone cells, meaning that opening the cells per se is not enough for extracting their protein. Proteins extracted with the aid of ultrafine milling had smaller particle sizes with significantly better water solubility (>2-fold) and rheological properties. Both wet milling and ultrafine milling significantly improved the removal of phytate during the wet fractionation process. Altogether, optimizing milling techniques offers a promising path to enhance accessibility to wheat bran proteins and their quality if carefully fine-tuned but other assistant technologies are necessary for boosting the recovery of the released protein from aleurone cells.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biobased and biodegradable polymer. This polymer is considered promising, but it is also rather expensive. The objective of this study was to compound PHBV with three different organic fillers considered waste: human hair waste (HHW), sawdust (SD) and chitin from shrimp shells. Thus, the cost of the biopolymer is reduced, and, at the same time, waste materials are valorised into something useful. The composites prepared were characterised by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile strength and scanning electron micrograph (SEM). Tests showed that chitin and HHW did not have a reinforcing effect on tensile strength while the SD increased the tensile strength at break to a certain degree. The biodegradation of the different composites was evaluated by a soil burial test for five months. The gravimetric test showed that neat PHBV was moderately degraded (about 5% weight loss) while reinforcing the polymer with organic waste clearly improved the biodegradation. The strongest biodegradation was achieved when the biopolymer was compounded with HHW (35% weight loss). The strong biodegradation of HHW was further demonstrated by characterisation by Fourier-transform infrared spectroscopy (FTIR) and solid-state nuclear magnetic resonance (NMR). Characterisation by SEM showed that the surfaces of the biodegraded samples were eroded.

Fungal mycelium is emerging as a source for sustainable bio-based materials. Fungal biomass of Aspergillus oryzae was prepared by cultivation on bread waste hydrolysate to valorize this abundant food waste. Chitin-glucan-rich alkali-insoluble material (AIM) was isolated from fungal biomass, formed into hydrogels, and wet spun into monofilaments. AIM in the form of fungal microfibers containing 0.09 g polymer of glucosamine (GlcN)/g AIM was subjected to freeze–thaw and deacetylation treatments to increase the amount of GlcN. The GlcN fraction was 0.19 and 0.34 g polymer of GlcN/g AIM, for AIM subjected to deacetylation (AIM-DAC) and freeze–thaw cycles and deacetylation (AIM-FRTH-DAC), respectively. The increased GlcN fraction enabled the formation of hydrogels via the protonation of amino groups after the addition of lactic acid. Morphological differences in the hydrogels included aggregation of the fungal microfibers in the AIM-DAC hydrogel, whereas the microfibers in the AIM-FRTH-DAC hydrogel had a porous and interconnected network. Rheological assessment revealed shear thinning behavior and gel properties of the produced hydrogels. Wet spinning of the hydrogels resulted in monofilaments with tensile strengths of up to 70 MPa and 12 % elongation at break. This demonstrates promising avenues for biomaterial development from fungal cell walls containing chitin-glucan via food waste valorization.

Background: Renewable materials made using environmentally friendly processes are in high demand as a solution to reduce the pollution created by the fashion industry. In recent years, there has been a growing trend in research on renewable materials focused on bio-based materials derived from fungi. Results: Recently, fungal cell wall material of a chitosan producing fungus has been wet spun to monofilaments. This paper presents a modification for the fungal monofilament spinning process, by the development of a benign method, dry gel spinning, to produce continuous monofilaments and twisted multifilament yarns, from fungal cell wall, that can be used in textile applications. The fungal biomass of Rhizopus delemar, grown using bread waste as a substrate, was subjected to alkali treatment with a dilute sodium hydroxide solution to isolate alkali-insoluble material (AIM), which mainly consists of the fungal cell wall. The treatment of AIM with dilute lactic acid resulted in hydrogel formation. The morphology of the hydrogels was pH dependent, and they exhibited shear thinning viscoelastic behavior. Dry gel spinning of the fungal hydrogels was first conducted using a simple lab-scale syringe pump to inject the hydrogels through a needle to form a monofilament, which was directly placed on a rotating receiver and left to dry at room temperature. The resulting monofilament was used to make twisted multifilament yarns. The process was then improved by incorporating a heated chamber for the quicker drying of the monofilaments (at 30⁰C). Finally, the spinning process was scaled up using a twin-screw microcompounder instead of the syringe pump. The monofilaments were several meters long and reached a tensile strength of 63 MPa with a % elongation at break of 14. When spinning was performed in the heated chamber, the tensile strength increased to 80 MPa and further increased to 103 MPa when a micro-compounder was used for spinning. Conclusion: The developed dry gel spinning method shows promising results in scalability and demonstrates the potential for renewable material production using fungi. This novel approach produces materials with mechanical properties comparable to those of conventional textile fibers. 

The Current study aimed at valorizing carrot pomace (CP), an abundant waste from the juice industry. A water-soluble fraction of CP was separated from solid fraction of CP (SFCP) and employed as feedstock for producing fungal biomass (FB) in bench-scale bioreactors. FB combined with SFCP were used to develop mycelium-based papers (MBP) using the wet-laid method. The potential and capacity of FB, SFCP and MBP to remove dye (methylene blue) from wastewater was then investigated. The maximum achieved dye removal was 92% when using a mixture of SFCP and FB in their suspended forms. The MBP with the lowest density (549 kg/m3) reached 83% dye elimination. The findings of this study support the valorization of carrot pomace, through environmentally benign processes, to mycelium-based papers with potential application in wastewater treatment.

Citrus waste has been used as a source of bioplastics for research in different ways. Because the juice industry produces significant amounts of residue each year, it would be advantageous to use the byproducts in the creation of new materials. Researchers have long explored eco-friendly methods to convert citrus and other organic waste into polymers for producing biodegradable films. The goal of this study is to create biofilms from orange waste (OW) and ginger waste (GW) using an ultrafine grinder and study the films’ properties. Since pectin has the ability to gel, and because cellulosic fibers are strong, citrus waste has been studied for its potential to produce biofilms. After being washed, dried, and milled, orange and ginger waste was shaped into films using a casting process. Tensile testing was used to determine the mechanical properties of biofilms, while dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) were used to determine their thermal properties. As the number of grinding cycles increased, the suspension’s viscosity increased from 29 mPa.s to 57 mPa.s for OW and from 217 mPa.s to 376 mPa.s for GW, while the particle size in the suspension significantly decreased. For OW and GW films, the highest tensile strength was 17 MPa and 15 MPa, respectively. The maximum strain obtained among all films was 4.8%. All the tested films were stable up to 150 °C, and maximum degradation occured after 300 °C.

Carrot pomace (CP) which is generated in a large volume in the juice production process, is rich in cellulose, hemicellulose, sugars, pectin, and minerals. However, in many previous investigations, only cellulose was purified and utilized while other components of CP were discarded as waste. Here, CP was valorized into fungal biomass and cellulose with the aim of utilizing all the CP components. Enzymatic pretreatments were applied to solubilize the digestible fraction of CP including hemicellulose, pectin, sucrose, and other sugars for fungal cultivation, while cellulose remained intact in the solid fraction. The dissolved fraction was utilized as a substrate for the cultivation of an edible fungus (Rhizopus delemar). Fungal cultivation was performed in shake flasks and bench-scale bioreactors. The highest fungal biomass concentration was obtained after pretreatment with invertase (5.01 g/L) after 72 h of cultivation (36 and 42% higher than the concentrations obtained after hemicellulase and pectinase treatments, respectively). Invertase pretreatment resulted in the hydrolysis of sucrose, which could then be taken up by the fungus. Carbohydrate analysis showed 28–33% glucan, 4.1–4.9% other polysaccharides, 0.01% lignin, and 2.7–7% ash in the CP residues after enzymatic pretreatment. Fourier transform infrared spectroscopy and thermogravimetric analysis also confirmed the presence of cellulose in this fraction. The obtained fungal biomass has a high potential for food or feed applications, or as a raw material for the development of biomaterials. Cellulose could be purified from the solid fraction and used for applications such as biobased-textiles or membranes for wastewater treatment, where pure cellulose is needed.