Search Results (193)

The increasing demand for food necessitates that agri-food systems adopt innovative techniques to enhance food production while optimizing the use of limited resources, such as water. In agriculture, hydrogels are being increasingly used to enhance water retention and reduce irrigation requirements. However, most of these materials are based on synthetic polymers that are not biodegradable. This raises serious environmental and health concerns, highlighting the urgent need for sustainable, biodegradable alternatives. Biomass-derived from agro-industrial waste presents a substantial potential for producing hydrogels, which can effectively function as water collectors and suppliers for crops. This review article provides a comprehensive overview of recent advancements in the application of agro-industrial waste for the formulation of hydrogels. Additionally, it offers a critical analysis of the development of hydrogels utilizing natural and compostable materials. Agro-industrial and food waste, which are rich in hemicellulose and cellulose, have been utilized to enhance the mechanical properties and water absorption capacity of hydrogels. These biomaterials hold significant potential for the development of effective hydrogels in agricultural applications; they can be either hybrid or natural materials that exhibit efficacy in enhancing seed germination, improving water retention capabilities, and facilitating the controlled release of fertilizers. Natural hydrogels derived from agro-industrial waste present a sustainable technological alternative that is environmentally benign. Full article

Bacterial nanocellulose (BNC) is a highly pure biopolymer with promising applications in the biomedical, food, and textile industries. However, the high production costs and low yields obtained in static conditions limit its scalability and industrial applications. This study addresses the sustainable production of BNC using a rotary disk bioreactor (RDB) and explores the use of grape pomace extract as an alternative carbon source for BNC production. Parameters such as the BNC production and biomass yield were evaluated using Komagataeibacter xylinus ATCC 53524 under different operational conditions (disk surface, rotation speed, and number of disks). The results showed that cellulose production increased using silicone-coated disks at 7–9 rpm (up to 2.72 g L⁻¹), while higher yields (5.23 g L⁻¹) were achieved when using grape pomace extract as the culture medium in comparison with conventional HS medium. FTIR and TGA characterizations confirmed that BNC obtained with grape pomace extract presents the same thermal and chemical characteristics than BNC produced with HS medium. This work provides insight into the feasibility of upscaling BNC production using a bioprocessing strategy, combining production in the RDB system and the use of an agro-industrial waste as a sustainable and cost-effective alternative. Full article

Climate change resulting from human development necessitates increased land use, food, and energy consumption, underscoring the need for sustainable development. Incorporating various feedstocks into value-added liquid fuels and bioproducts is essential for achieving sustainability. Most biomass consists of cell walls, which serve as a primary carbon source for bioenergy and biorefinery processes. This structure contains a cellulose core, where lignin and hemicelluloses are crosslinked and embedded in a pectin matrix, forming diverse polysaccharide architectures across different species and tissues. Nineteen agro-industrial waste products were analyzed for their potential use in a circular economy. The analysis included cell wall composition, saccharification, and calorific potential. Thermal capacity and degradation were similar among the evaluated wastes. The feedstocks of corn cob, corn straw, soybean husk, and industry paper residue exhibited a higher saccharification capacity despite having lower lignin and uronic acid contents, with cell walls comprising 30% glucose and 60% xylose. Therefore, corn, soybeans, industrial paper residue, and sugarcane are more promising for bioethanol production. Additionally, duckweed, barley, sorghum, wheat, rice, bean, and coffee residues could serve as feedstocks for other by-products in green chemistry, generating valuable products. Our findings show that agro-industrial residues display a variety of polymers that are functional for various applications in different industry sectors. Full article

Introducing and compacting lignocellulosic biomass in aluminum structures, though recommendable in terms of higher sustainability, the potential use of agro-waste and significant weight reduction, still represents a challenge. This is due to the variability of biomass performance and to its limited compatibility with the metal. Another question may concern possible moisture penetration in the structure, which may reduce environmental resistance and result in local degradation, such as wear or even corrosion. Despite these limitations, this hybridization enjoys increasing success. Two forms are possibly available for this: introduction into metal matrix composites (MMCs), normally in the form of char from biomass combustion, or laminate reinforcement as the core for fiber metal laminates (FMLs). These two cases are treated alongside each other in this review, first because they may represent two combined options for recycling the same biomass into high-profile structures, aimed primarily at the aerospace industry. Moreover, as discussed above, the effect on the aluminum alloy can be compared and the forces to which they are subjected might be of a similar type, most particularly in terms of their hardness and impact. Both cases considered, MMCs and FMLs involved over time many lignocellulosic residues, starting from the most classical bast species, i.e., flax, hemp, sisal, kenaf, etc., and extending also to less diffuse ones, especially in view of the introduction of biomass as secondary, or residual, raw materials. Full article

Coastal regions of Ecuador, particularly Esmeraldas and Manabí, face significant challenges related to energy access, waste management, and sustainable agricultural development. This study evaluates the renewable energy potential of cocoa waste biomass generated by smallholder farms in these provinces. A total of 20 cocoa farms, either certified or in the process of certification under the Rainforest Alliance standard, were surveyed to quantify the volume of agricultural and agro-industrial residues. Residual biomass generation ranged from 50 to 6500 tons per year, depending on farm size, planting density, and management practices. Spatial analysis revealed that Esmeraldas holds the highest concentration of cocoa waste biomass, with some farms reaching a gross energy potential of up to 89.07 TJ/year. Using thermochemical conversion scenarios, effective energy potential was estimated, and 75% of the farms exceeded the viability threshold of 100 MWh/year. The results confirm the feasibility of cocoa biomass as a renewable energy source, mainly when managed collectively at the community level. Incorporating this waste into decentralized energy systems supports circular economy models, enhances energy self-sufficiency, and aligns with sustainable supply chain goals promoted by certification schemes. This study contributes to national efforts in energy diversification and provides a replicable model for integrating renewable energy into rural agricultural systems. Full article

Membrane processes are extensively employed in a range of industrial and food applications. Due to growing environmental concerns and the introduction of regulatory measures, it is imperative to develop innovative membrane materials that can effectively replace petrochemical-based polymers, in line with the principles of a circular economy. The focus of this review is the use of polysaccharides for obtaining films/membranes for food and industrial applications using selected case studies. Besides the polysaccharides extracted from biomass, the valorization of agrifood residues and the use of plants adapted to arid lands (i.e., cactus) to produce polysaccharide films for food packaging is addressed. Moreover, microbial polysaccharides produced using renewable resources present a significant alternative to commercial hydrophilic membranes for gases and ethanol dehydration. To meet industry requirements, the mechanical and barrier properties of the films can be improved by the inclusion of inert impermeable fillers and/or the chemical modification of the polysaccharides. The adsorption of proteins, dyes, and pharmaceutical compounds using a cellulose-based polymer is discussed. Despite their unique characteristics, polysaccharide production costs are still higher than most synthetic polymers. This is a challenge that can be overcome by scaling up the production and by valorizing agro-industrial wastes and by-products to make the application of polysaccharide membranes/films in the food and industry sectors more widespread. Full article

Hydrothermal processing has emerged as a promising clean technology for managing the substantial amounts of agro-industrial waste generated worldwide. This study aims to introduce a clean technology approach to biomass valorization processes by exploring the hydrothermal conversion of two distinct biomass feedstocks, peapods and coffee cherries, into valuable platform chemicals through the use of homogeneous acid catalysts. The hydrothermal valorization experiments were conducted in a 500 mL reactor at 180 °C for 1 h with a 1:20 biomass–acid solution ratio, utilizing a set of organic and inorganic acids as catalysts. The chemical compositions of the biomass feedstocks were analyzed, revealing significant differences in their cellulose (20.2 wt% in peapods; 27.6 wt% in coffee cherries), hemicellulose (17.4 wt% in peapods; 12.5 wt% in coffee cherries), and lignin (5.0 wt% in peapods; 13.7 wt% in coffee cherries) contents. Without the use of catalysts, peapods yielded 45.128 wt% platform chemicals, outperforming coffee cherries, which produced 32.598 wt%. The introduction of various acid catalysts influenced the yields and selectivity of platform chemicals. Sulfuric acid enhanced sugar production, yielding 62.936 wt% from peapods and 51.236 wt% from coffee cherries. Hydrochloric acid selectively favored sugar production but resulted in decreased overall yields. Nitric acid facilitated the conversion of both biomass types, yielding 35.223 wt% from coffee cherries and 40.315 wt% from peapods. Adipic acid achieved the highest overall yields, with 53.668 wt% for coffee cherries and 65.165 wt% for peapods, while also increasing levulinic acid production. Acetic acid significantly increased sugar yields, which reached 50.427 wt% with peapods. The findings highlight the potential of hydrothermal valorization as a clean technology for biomass conversion and underscores the importance of tailoring catalyst selection and process conditions to optimize the valorization of biomass feedstocks. Full article

The use of agro-industrial waste, such as wood ash or biomass ash, has been adopted as an alternative to synthetic fertilizers for providing nutrients to plants. This study aimed to evaluate the levels of primary and secondary macronutrients in soil cultivated with chrysanthemum under different types of fertilization management: organic, organomineral, and mineral, with and without liming. The experiment was conducted in a greenhouse for 185 days, using a randomized blocks design in a 5 × 2 factorial scheme: five fertilization types (incubated and unincubated wood ash, organomineral fertilizer, mineral fertilizer, and control) and two levels of liming (without liming and 70% base saturation) with five replicates. The soil used was Oxisol. The phosphorus, potassium, calcium, magnesium, and sulfur contents in the soil after cultivation were analyzed. There was a 77% increase in potassium in treatments with ash compared to treatments without ash. The corrected soil presented 173.2 mg dm⁻³ of potassium, compared to 153.6 mg dm⁻³ in the uncorrected soil, an increase of 11.6%. The calcium levels increased by 60% with the application of ash (incubated or not) and organomineral fertilizer, compared to soils without ash. Liming increased calcium by 1.12 cmol_c dm⁻³. Fertilizers with ash associated with liming resulted in higher magnesium levels. The sulfur content varied according to the fertilizer, with non-incubated ash showing the highest value (69.11 mg dm⁻³) compared to the control (11.08 mg dm⁻³), a difference of 83.96%. Organomineral fertilizer is an alternative for increasing the availability of macronutrients in the soil, allowing a second cropping cycle without the need to manage soil fertility, contributing to sustainable agriculture, encouraging the reuse of waste, and reducing the use of mineral fertilizers. Full article

This study investigates the potential of sugar beet pulp (SBP), a lignocellulosic by-product of sugar production, as a low-cost substrate for biohydrogen and biomass generation using Escherichia coli under dark fermentation conditions. Two strains—BW25113 wild-type and a genetically engineered septuple mutant—were employed. SBP was pretreated via thermochemical hydrolysis, and the effects of substrate concentration, dilution, and glycerol supplementation were evaluated. Hydrogen production was highly dependent on substrate dilution and nutrient balance. The septuple mutant achieved the highest H₂ yield in 30 g L⁻¹ SBP hydrolysate (0.75% sulfuric acid) at 5× dilution with glycerol, reaching 12.06 mmol H₂ (g sugar)⁻¹ and 0.28 mmol H₂ (g waste)⁻¹, while the wild type under the same conditions yielded 3.78 mmol H₂ (g sugar)⁻¹ and 0.25 mmol H₂ (g waste)⁻¹. In contrast, undiluted hydrolysates favored biomass accumulation over H₂ production, with the highest biomass yield (0.3 g CDW L⁻¹) obtained using the septuple mutant in 30 g L⁻¹ SBP hydrolysate without glycerol. These findings highlight the potential of genetically optimized E. coli and optimized hydrolysate conditions to enhance the valorization of agro-industrial waste, supporting future advances in sustainable hydrogen bioeconomy and integrated waste biorefineries. Full article

Large-scale cultivation of cyanobacteria is often limited by the high cost of synthetic culture medium and the environmental impact of nutrient consumption. Cheese whey, a major agro-industrial waste product, is rich in organic and inorganic nutrients, making it a promising low-cost alternative for microbial growth while addressing waste bioremediation. This study investigates the growth performance and the biochemical composition of four different cyanobacterial species (Phormidium sp., Synechocystis sp., Chlorogloeopsis fritschii, and Arthrospira platensis), cultivated in cheese whey (CW). Pretreated CW was used at 20% and 100% v/v concentrations. All species grew satisfactorily in both concentrations, reaching biomass above 4 g L⁻¹ (in 100% v/v CW) and 2 g L⁻¹ (in 20% v/v CW). The highest μ_max value (0.28 ± 0.02 d⁻¹) was presented by Synechocystis sp. grown in 20% CW. Waste bioremediation of both 20 and 100% v/v CW demonstrated effective nutrient removal, with COD removal exceeding 50% for most species, while total nitrogen (TN) and total phosphorus (TP) removals reached up to 33% and 32%, respectively. Biochemical composition analysis revealed high carbohydrate and protein content, while lipid content remained below 15% in all cases. Interestingly, C. fritschii accumulated 11% w/w polyhydroxyalkanoates (PHAs) during the last day of cultivation in 20% v/v CW. These findings highlight the potential of C. fritschii as a valuable candidate for integration into bioprocesses aimed at sustainable bioplastic production. Its ability to synthesize PHAs from agro-industrial waste not only enhances the economic viability of the process but also aligns with circular economy principles. This study is a primary step towards establishing a biorefinery concept for the cultivation of cyanobacterial species in cheese whey-based wastewater streams. Full article

Biomass is an energy source with variable physico-chemical properties. Thermal treatments lower moisture and volatile matter contents. They also raise the high heating value (HHV). This is especially desirable for agro-wastes with low-energy potential, like maize cobs. To make pellets from biomass, it is important to keep the lignin intact. It is responsible for particle adhesion. This paper presents a study focused on high-temperature drying of maize cobs. The process temperatures were selected from a range between 60 and 220 °C. The upper temperature limit prevents significant lignin breakdown. We also do not exceed the self-ignition temperature of the raw material. The study analyzed changes in basic technical parameters. These include moisture content, ash content, volatile matter, and HHV. We tested the grinding and densification process. We measured the raw material’s particle size distribution (PSD), specific density, and the mechanical durability (DU) of the agglomerates. The study showed a positive effect of high-temperature drying on the technical parameters. We found that the drying of corn cobs at a temperature of 180 °C gives the best results. Both PSD and DU values indicate that it is possible to create quality compacted biofuels from this material. Full article

Biogas production from agricultural waste reduces methane emissions and addresses climate change challenges by converting livestock and organic waste into energy. This study analyzed biogas production in agricultural enterprises under the European Green Deal, the advantages of biogas as an energy source, and the use of digestate in agriculture. The raw material for biogas production from agro-industrial wastes in Ukraine has been investigated, showing that the country’s biogas production potential amounts to 34.59 billion m³, including 0.65 billion m³ from processing plant wastes. The main types of biomass that can be used for biogas production in Ukraine are crop residues (71.4%), manure (26.6%), and food industry waste (2.0%). The implementation of biogas production projects will reduce greenhouse gas emissions by 3.98 billion tons of CO₂ and increase profits through electricity sales. This study examines the barriers and prospects for the development of electricity generation from biogas in Ukraine in the context of the integration of Ukraine’s energy system into the EU energy space. Directions for developing the biogas industry, focusing on electricity production within the framework of European decarbonization initiatives, will enhance the energy security of Ukraine and the EU. Estimating the energy production from agricultural waste allows for determining biogas output from organic waste. A regional biogas cluster model was developed based on the agro-industrial complex, which combines the production of biogas, electricity, water, and biofertilizers with increased efficiency and regional sustainable development. Full article

Spent mushroom substrate (SMS), spent coffee grounds from espresso production (SCG), faba bean harvest residues (FBR), pistachio shells (PS) wheat straw (WS) (control) agro-industrial waste were combined in different ratios, with or without supplements (wheat bran, soybean flour), to create novel substrates for Pleurotus columbinus growth. The impact of the substrates on the mycelial growth rate (Kr), biomass production, laccase, total cellulases and carbohydrate synthesis, along with the C and N consumption by P. columbinus, were examined in fully colonized substrates. The incubation period, earliness and biological efficiency (B.E.) (%) were also determined. Then, the intracellular polysaccharide (ICP) contents of the P. columbinus produced mushrooms were evaluated in the most promising substrates. P. columbinus was grown successfully in a wide range of C/N ratios of substrates and the fastest Kr (7.6 mm/d) was detected on the 70 SMS-30 FBR, without supplements, whereas substrates consisting of SCG enhanced biomass production (700.0–803.7 mg/g d.w.). SMS and PS or SCG led to the shortest incubation and earliness period of P. columbinus. The C content was reduced and the N content was substantially increased in all the colonized substrates. The 70 SMS-30 FBR and 80 SMS considerably enhanced the laccase production (up to 59,933.4 U/g d.w.) and substrates consisting of PS promoted total cellulases activities. Greater amounts of carbohydrates (3.8–17.4 mg/g d.w.) than that in the control were recorded for all the substrates. The combination of SMS and SCG or WS led to the highest B.E. values (59.3–87.1%) and ICP amounts (34.7–45.9%, w/w), regardless of the supplement addition. These findings support the effective utilization of agro-industrial waste in P. columbinus cultivation, producing high-value-added compounds and supporting mushroom growth. Full article

The increasing generation of agro-industrial waste and its improper disposal have raised significant environmental concerns, highlighting the urgent need for sustainable alternatives which would repurpose these materials. In this context, enzymes such as endoglucanase play a critical role in degrading lignin–cellulose biomass by catalyzing the breakdown of β-1,4-glycosidic bonds in cellulose, thereby converting it into fermentable sugars with diverse industrial applications. This study aimed to investigate the production, purification, and characterization of an endoglucanase produced by the fungus Pleurotus djamor PLO13, using coconut fiber, sugarcane bagasse, wheat bran, and pineapple crown as substrates. Endoglucanase activity was measured by the Miller method (1959), using 2% (w/v) carboxymethyl cellulose (CMC) as substrate. Solid-state fermentation (SSF) was found to be highly efficient for enzyme synthesis, with wheat bran emerging as the most effective substrate, yielding an enzyme production of 7.19 U after 120 h of cultivation. The endoglucanase was purified through ethanol precipitation and ion-exchange chromatography using DEAE-Sepharose, achieving a recovery rate of 110%, possibly due to removal of inhibitors present in the crude extract. The purified enzyme exhibited stability across a broad pH range and thermostability, with optimal activity at pH 5.0 and 50 °C. Furthermore, the enzyme was activated by EDTA, Mn²⁺, and Ca²⁺, while being inhibited by Mg²⁺. Notably, the enzyme demonstrated halotolerance, with activity increasing by 60% upon the addition of 3 M NaCl. Kinetic analysis revealed that the purified enzyme showed affinity to the CMC substrate at the analyzed parameters (pH 5.0 and 50 °C), with Km and Vmax values of 0.0997 mg/mL and 112.2 µg/min/mL, respectively. These findings suggest that the endoglucanase from P. djamor PLO13 has promising potential for biotechnological applications, underscoring the feasibility of the use of lignocellulosic waste as sustainable substrates in industrial processes. Full article

Lignin, the most abundant aromatic polymer in nature, plays a critical role in lignocellulosic biomasses by providing structural support. However, its presence complicates the industrial exploitation of these materials for biofuels, paper production and other high-value compounds. Annually, the industrial extraction of lignin reaches an estimated 225 million tons, yet only a fraction is recovered for reuse, with most incinerated as low-value fuel. The growing interest in lignin potential has sparked research into sustainable recovery methods from lignocellulosic agro-industrial wastes. This review examines the chemical, physical and physicochemical processes for isolating lignin, focusing on innovative, sustainable technologies that align with the principles of a circular economy. Key challenges include lignin structural complexity and heterogeneity, which hinder its efficient extraction and application. Nonetheless, its properties such as high thermal stability, biodegradability and abundant carbon content place lignin as a promising material for diverse industrial applications, including chemical synthesis and energy generation. A structured analysis of advancements in lignin extraction, characterization and valorization offers insights into transforming this undervalued by-product into a vital resource, reducing reliance on non-renewable materials while addressing environmental sustainability. Full article