Search Results (121)

Driven by the energy transition within the framework of the United Nations Framework Convention on Climate Change, second-generation (2G) ethanol stands out as a technical and sustainable alternative to fossil fuels. Although first-generation ethanol, produced from saccharine and starchy feedstocks, represents an advance in mitigating emissions, its expansion is limited by competition with areas destined for food production. In this context, 2G ethanol, obtained from residual lignocellulosic biomass, emerges as a strategic route for diversifying and expanding the renewable energy matrix. Thus, this work discusses the current state of 2G ethanol technology based on the gradual growth in production and the consolidation of this route over the last few years. Industrial second-generation ethanol plants operating around the world demonstrate the high potential of agricultural waste as a raw material, particularly corn straw in the United States, which offers a lower cost and significant yield in the production of this biofuel. Similarly, in Brazil, sugarcane by-products, especially bagasse and straw, are consolidating as the main sources for 2G ethanol, integrated into the biorefinery concept and the valorization of by-products obtained during the 2G ethanol production process. However, despite the wide availability of lignocellulosic biomass and its high productive potential, the consolidation of 2G ethanol is still conditioned by technical and economic challenges, especially the high costs associated with pretreatment stages and enzymatic cocktails, as well as the formation of inhibitory compounds that compromise the efficiency of the process. Genetic engineering plays a particularly important role in the development of microorganisms to produce more efficient enzymatic cocktails and to ferment hexoses and pentoses (C₆ and C₅ sugars) into ethanol. In this scenario, not only are technological limitations important but also public policies and tax incentives, combined with the integration of the biorefinery concept and the valorization of (by)products, which prove fundamental to reducing costs, increasing process efficiency, and ensuring the economic viability and sustainability of second-generation ethanol. Full article

Biofouling communities are usually managed as pests in aquaculture, yet their natural proliferation in fish farms makes them also promising IMTA extractive components. The growth and biomass production of four dominant macrofoulers, Mytilus galloprovincialis (mussels), Sabella spallanzanii (polychaete worms), Phallusia mammillata and Styela plicata (ascidians), were evaluated under a novel IMTA system in the Ionian Sea (southern Italy). Coconut-fiber ropes (10 m) were deployed around fish cages in October 2022 and monitored over a 1-year cycle. Monthly density, length-frequency and cohort analyses combined with species-specific length-weight relationships were used to estimate target species’ growth and biomass. Mytilus and Sabella showed single-cohort dynamics, with densities steadily declining over time, whereas ascidians displayed continuous recruitment allowing for additional rope-deployment windows. Specific growth rates in length were significantly higher in Phallusia and Sabella (≈25% month⁻¹) than in Mytilus and Styela (≈17 and 22% month⁻¹). Total macrofouling biomass (live weight) increased from ≈350 kg in May to a peak of ≈2500 kg in August, remaining as high in October. Mytilus and Sabella accounted for 60–80% of total biomass while ascidians contributed 20–40%. Beyond environmental restoration, this multispecies biomass offers several potential commercial opportunities and could be further valorized through biorefinery-based cascading extraction, including final conversion into bioenergy. Overall, IMTA could leverage traditionally undesired fouling organisms as multifunctional crops, enhancing bioremediation while supporting circular blue-bioeconomy principles. Future research should focus on optimizing rope deployment timing, harvesting strategies, and biomass valorization pathways to fully exploit the emerging potential of integrating multispecies fouling biomass within IMTA systems. Full article

The worldwide transition to renewable energy systems is motivated by diminishing fossil fuel availability and the intensifying consequences of climate change. This study presents a Mixed-Integer Linear Programming (MILP) model for designing and optimising the bio-fuel and electricity supply chain in Colombia, using sugarcane as the main feedstock and integrating microalgae cultivation in vinasse. Six alternative biorefinery configurations and four microalgae conversion pathways were evaluated to inform strategic planning. The optimisation results indicate that microalgae achieve higher energy yields per unit of land than sugarcane. Ethanol production from sugarcane could meet all of Colombia’s gasoline demand, while diesel and sustainable aviation fuel derived from microalgae could supply around 9% and 16%, respectively, of the country’s consumption. Further-more, pelletised bagasse emerges as a viable alternative to replace part of the coal used in thermoelectric plants. From an economic perspective, all scenarios achieve a positive net present value, confirming their profitability. Sensitivity analysis highlights the critical factors influencing the deployment of distilleries as ethanol price, algae productivity, and sugarcane cost. Furthermore, transportation costs play a decisive role in the geographic location of microalgae-based facilities and the distribution of their products. Full article

Astaxanthin, a high-value keto-carotenoid with potent antioxidant and health-promoting properties, has gained global attention as a sustainable nutraceutical and biotechnological product. The green microalgae Haematococcus pluvialis and Chromochloris zofingiensis represent two promising natural producers, yet they differ markedly in physiology, productivity, and industrial scalability. This review provides a focused comparative analysis of these two species, emphasizing their quantitative performance differences. H. pluvialis can accumulate astaxanthin up to ~3–5% of dry biomass but typically reaches biomass densities of only 5–10 g L⁻¹, whereas C. zofingiensis achieves ultrahigh biomass concentrations of 100–220 g L⁻¹ under heterotrophic fed-batch fermentation, although its astaxanthin content is much lower (~0.1–0.5% DW). While H. pluvialis remains the benchmark for natural astaxanthin due to its exceptionally high cellular content, its thick cell wall, slow growth, and strict phototrophic requirements impose major cost and operational barriers. In contrast, C. zofingiensis exhibits rapid and flexible growth under heterotrophic, mixotrophic, or phototrophic conditions and can achieve ultrahigh biomass in fermentation, though its ketocarotenoid flux and astaxanthin accumulation remain comparatively limited. Meanwhile, a rapidly growing patent landscape demonstrates global technological competition, with major portfolios emerging in China, the United States, and Europe, spanning chemical synthesis, microbial fermentation, algal metabolic engineering, and high-density cultivation methods. These patents reveal clear innovation trends—ranging from solvent-free green synthesis routes to engineered microalgae and yeast chassis for enhanced astaxanthin production—which increasingly shape industrial development strategies. By synthesizing recent advances in metabolic engineering, two-stage cultivation, and green extraction technologies, this review identifies key knowledge gaps and outlines a practical roadmap for developing next-generation astaxanthin biorefineries, with an emphasis on scalable production and future integration into broader biorefinery frameworks. The findings aim to guide future research and provide actionable insights for scaling sustainable, cost-effective production of natural astaxanthin. Full article

Alkaline delignification is a keystone pretreatment that governs carbohydrate accessibility, energy use, and yields across pulp and biorefinery value chains, yet its kinetic understanding remains fragmented and largely confined to bench-scale studies. This review provides an integrated assessment of the evolution and current state of kinetic approaches applied to alkaline delignification of lignocellulosic biomass, aiming to bridge academic research and industrial application. A systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta Analyses) guidelines identified 74 peer-reviewed articles and 359 patents published between 1995 and 2025. Kinetic models were classified into conventional (nth-order and pseudo-first-order) and emerging categories (Avrami/Š–B, diffusion-based, mechanistic multistep, isoconversional, and ML/statistical). The results show that pseudo-first-order kinetics and batch-scale studies dominate the literature, while pilot-scale validation and hybrid mechanistic data-driven frameworks remain limited. Patent analysis revealed technological convergence within D21C and C08B IPC domains, reflecting growing industrial interest in alkaline pulping and cellulose valorization. Unlike previous reviews, this work uniquely integrates conventional and emerging kinetic models with a patent-based technological perspective, providing a unified view of academic and industrial progress. The insights presented here provide a foundation for advancing future research, particularly by encouraging the development of standardized experimental protocols and the validation of kinetic models across multiple scales. Moreover, this review provides a consolidated reference for both academic researchers and industrial practitioners seeking to enhance delignification efficiency, reduce reagent consumption, and improve the sustainability of biorefinery processes. Full article

Citrus fruits are among the most important global crops, with annual production exceeding 160 million tons. Processing produces significant waste, mainly peels, seeds, and pulp, which can make up to fifty percent of the fruit’s mass. This review critically examines innovative ways to valorize these byproducts. Recent research shows that peels, seeds, and pulp can be converted into high-value materials, including biocomposites and biomaterials, marking a shift from traditional uses like animal feed and biogas production. Notable innovations include smart packaging, pectin-based wound dressings, and biodegradable polymers for sustainable electronics. Advanced green extraction methods, such as deep eutectic solvents, have achieved extraction yields over 85% for flavonoids. Additionally, multifunctional biorefineries processing citrus and olive residues have increased biogas yields by 38–42%. The review explores emerging applications in nanotechnology, nutraceuticals, biodegradable polymers, and functional coatings, all aligned with principles of circular economy and green chemistry. These advances suggest that citrus waste can play a significant role in sustainability efforts and new market development. The review also discusses barriers to adoption, including scalability challenges, regulatory limits, and consumer acceptance, from both global and regional viewpoints. Full article

Pea protein isolates (PPIs) from Pisum sativum have emerged as strategic ingredients at the interface of nutrition, sustainability, and functional food design. This review synthesizes advances linking isolation procedures with molecular structure and techno-functional performance. We compare alkaline extraction–isoelectric precipitation with wet and dry fractionation, as well as green/fermentation-assisted methods, highlighting the purity–functionality trade-offs driven by denaturation, aggregation, and the removal of anti-nutritional factors. We relate globulin composition (vicilin/legumin ratio), secondary/tertiary structure, and disulfide chemistry to interfacial activity, solubility, gelation thresholds, and long-term emulsion stability. Structure-guided engineering strategies are critically evaluated, including enzymatic hydrolysis, deamidation, transglutaminase cross-linking, ultrasound, high-pressure homogenization, pH shifting, cold plasma, and selected chemical/glycation approaches. Application case studies cover high-moisture texturization for meat analogues, emulsion and Pickering systems, fermented dairy alternatives, edible films, and bioactive peptide-oriented nutraceuticals. We identify bottlenecks—weak native gel networks, off-flavors, acidic pH performance, and batch variability—and outline process controls and synergistic modifications that close functionality gaps relative to animal proteins. Finally, we discuss sustainability and biorefinery opportunities that valorize soluble peptide streams alongside globulin-rich isolates. By integrating extraction, structure, and function, the review provides a roadmap for designing PPI with predictable, application-specific performance. Full article

Tree bark, a renewable byproduct of the forest industry, has long been recognized as a rich source of bioactive and structural compounds, including polyphenols, tannins, triterpenes, and suberinic acids. Over recent decades, numerous studies have explored bark extraction processes aimed at recovering these valuable substances. However, the substantial quantities of solid and liquid residues remaining after extraction are still largely overlooked despite their significant potential for further valorization. This review summarizes the current state of research on bark extraction, highlighting the diversity of applied techniques from conventional solvent extraction to advanced green methods such as organosolv, subcritical water, and supercritical CO₂ extraction. Particular emphasis is placed on post-extraction residues, which remain rich in lignocellulosic, suberinic and phenolic compounds suitable for the development of bio-based materials, composites and functional chemicals. Importantly, this review introduces a novel perspective by evaluating post-extraction residues with the same significance as primary bark extracts, emphasizing their un-tapped potential within emerging bark biorefinery concepts. The review identifies existing knowledge gaps related to the chemical characterization, recovery strategies and industrial integration of these byproducts. Finally, it outlines future research directions focused on transforming bark extraction residues into high value sustainable materials fully aligned with the principles of the circular bioeconomy and zero waste processing. Full article

Postharvest operations are cost intensive in microalgae production, and when electrocoagulation–electroflotation (EC/EF) with aluminum anodes is used, aluminum can remain associated with biomass and wash streams; hence, a selective postwash process is needed. Accordingly, this study defined an operational window for aluminum desorption that preserves the energetic advantage of EC/EF. A response-surface design (I-optimal/CCD) was used to evaluate the effects of the EDTA concentration (1–100 mM), contact time (5–20 min), mixing speed (100–300 rpm), and pH (6–10) on EC/EF-harvested Chlorella sp. biomass, with ANOVA and model diagnostics supporting adequacy. EDTA concentration and mixing emerged as significant factors, whereas time and pH acted mainly through interactions; moreover, quadratic terms for EDTA and mixing indicated diminishing returns at high levels. Consequently, the surface predicted an optimum near EDTA ≈ 65 mM, time ≈ 20 min, pH 10, and 100 rpm, corresponding to ~97% aluminum removal. Importantly, a confirmation run under these conditions across eight chlorophyte strains consistently achieved >95% removal, revealing narrow dispersion yet statistically distinguishable means. Taken together, coupling EC/EF with an EDTA postwash operation in the identified window effectively limits aluminum carry-over in microalgal biomass and, therefore, provides a reproducible basis for downstream conditioning and potential recirculation within biorefinery schemes. Full article

Lignocellulosic biomass—the non-edible fraction of plants composed of cellulose, hemicellulose, and lignin—is the most abundant renewable carbon resource and a key lever for shifting from fossil to bio-based production. Agro-industrial residues (straws, cobs, shells, bagasse, brewery spent grains, etc.) offer low-cost, widely available feedstocks but are difficult to process because their polymers form a tightly integrated, three-dimensional matrix. Within this matrix, lignin provides rigidity, hydrophobicity, and defense, yet its heterogeneity and recalcitrance impede saccharification and upgrading. Today, most technical lignin from pulping and emerging biorefineries is burned for energy, despite growing opportunities to valorize it directly as a macromolecule (e.g., adhesives, foams, carbon precursors, UV/antioxidant additives) or via depolymerization to low-molecular-weight aromatics for fuels and chemicals. Extraction route and severity strongly condition lignin structure linkages (coumaryl-, coniferyl-, and sinapyl-alcohol ratios), determining reactivity, solubility, and product selectivity. Advances in selective fractionation, reductive/oxidative catalysis, and hybrid chemo-biological routes are improving yields while limiting condensation. Remaining barriers include feedstock variability, solvent and catalyst recovery, hydrogen and energy intensity, and market adoption (e.g., low-emission adhesives). Elevating lignin from fuel to product within integrated biorefineries can unlock significant environmental and economic benefits. Full article

Hydrogels derived from natural and synthetic polymers have emerged as versatile materials with wide applications in food science, biotechnology, and health-related sectors, providing unique opportunities to encapsulate, protect, and deliver bioactive compounds, as well as to create new textures and functional properties in food systems. This review summarizes the latest advances in the design and application of hydrogels, highlighting the critical relationship between polymer structure, crosslinking strategies, and functional performance. The analysis reveals that while significant progress has been achieved, challenges persist in scaling laboratory-scale hydrogel systems to industrially relevant processes, where stability, reproducibility, and regulatory acceptance remain major bottlenecks. Emerging directions in the field include the development of smart hydrogels that respond to environmental stimuli (pH, temperature, or enzymatic activity), sustainable fabrication routes using renewable biopolymers, integration with advanced processing technologies such as 3D printing or microfluidics, and biorefinery approaches emphasizing their role in valorizing agro-industrial by-products into high-value functional materials. Hydrogels represent a promising platform at the interface of polymer science, food technology, and biotechnology, whose continued development will depend on multidisciplinary innovation aiming to meet consumer demands for sustainable, safe, and health-promoting food systems. Full article

The growing global demand for clean energy and sustainability has increased interest in lignocellulosic biomass as a viable alternative to conventional fossil fuels. Among the various biomass resources, sugarcane bagasse, an abundant agro-industrial by-product, has emerged as a promising feedstock to produce renewable fuels and value-added chemicals. Its high carbohydrate content offers significant potential for bioconversion. However, its complex and recalcitrant lignocellulosic matrix presents significant challenges that necessitate advanced pretreatment techniques to improve enzymatic digestibility and fermentation efficiency. This review consolidates recent developments in the valorization of sugarcane bagasse focusing on innovative pretreatment and fermentation strategies for sustainable bioethanol production. It emphasizes the synergistic benefits of integrating various pretreatment and fermentation methods to improve bioethanol yields, reduce processing costs and enhance overall process sustainability. This review further explores recent technological advancements, the impact of fermentation inhibitor, and emerging strategies to overcome these challenges through microbial strains and innovative fermentation methods. Additionally, it highlights the multi-faceted advantages of bagasse valorization, including waste minimization, renewable energy production and the promotion of sustainable agricultural practices. By evaluating the current state of research and outlining future perspectives, this paper serves as a comprehensive guide to advancing the valorization of sugarcane bagasse in the transition towards a low-carbon economy. The novelty of this review lies in its holistic integration of technological, economic, and policy perspectives, uniquely addressing the scalability of integrated pretreatment and fermentation processes for sugarcane bagasse, and outlining practical pathways for their translation from laboratory to sustainable industrial biorefineries within the circular bioeconomy framework. Full article

This research proposes a bioeconomy model that integrates the principles of Marketing 3.0 with the concept of a biorefinery to valorize the Creole-Antillean avocado cultivated in the Montes de María region, Colombia. The study emerges from the absence of commercial strategies that articulate social responsibility and economic viability in the use of agricultural by-products, considering that the current industry is almost exclusively focused on the Hass variety. The methodology employed a mixed-methods approach, combining quantitative and qualitative analyses. Market studies, consumer segmentation, competition and trend analyses were conducted, along with the use of the TradeMap platform to identify export opportunities and the international positioning of avocado-derived products. In the experimental phase, the production processes were validated: bio-oil was extracted through the Soxhlet method using solvents, while chlorophyll and biocontrol agents were isolated with ethanol, ensuring efficiency and scalability. The results obtained through Aspen Plus simulation were validated by comparing software outputs with data reported in the literature. The model includes a corporate social responsibility section that evaluates the regional impact, highlighting job creation, community inclusion, and the strengthening of the social fabric. Results show that in 2023, Mexico led exports with 1,220,919 tons, followed by the Netherlands and Peru, while Colombia reached 114,741 tons, consolidating itself as a country with high growth potential. The findings suggest that the valorization of the Creole-Antillean variety represents a strategic opportunity to diversify the agroindustry, strengthen competitiveness, create employment, reduce waste, and guide investment decisions in bioeconomy, sustainability, promoting rural development and green innovation in Colombia. Full article

Background/Objectives: Orange peels (OP), a major by-product of the juice industry, are rich in bioactive compounds (phenolic compounds, pectin, carotenoids, and essential oils). Its valorization represents a promising route to reduce food waste and foster a circular bioeconomy. This review aimed to map scientific progress in OP upcycling, focusing on the extraction of bioactive ingredients for human nutrition and integrated biorefinery approaches aligned with zero-waste principles. Methods: A bibliometric analysis and a scoping review were conducted covering studies published between 2003 and 2023. Scopus database and VOSviewer was usedto identify research trends, hotspots, and gaps. Conventional and emerging green extraction methods were critically compared, and integrated biorefinery strategies for maximizing OP valorization were systematically assessed. Results: The analysis revealed an exponential rise in OP research over the past decade, reflecting growing interest in sustainable food waste valorization. Polyphenol- and pectin-rich extracts are currently the focus of research and applications, driven by their high economic and nutritional value. Innovative multi-extraction and zero-waste biorefinery models have emerged, yet most remain at low technological readiness levels. Carotenoids and other bioactive compounds remain underexplored, and challenges persist regarding standardization and scalability. Conclusions: OP valorization is shifting towards integrated green extraction and biorefinery frameworks that address clean-label demands, promote circular economy goals, and align with the Sustainable Development Goals. Future research should prioritize (i) standardized protocols, (ii) scalable green extraction technologies, (iii) the inclusion of underutilized compounds such as carotenoids, and (iv) regulatory pathways to accelerate industrial translation. Full article

The global reliance on fossil fuels has caused severe environmental challenges, emphasizing the urgent need for sustainable and renewable energy sources. Bioethanol production from lignocellulosic biomass has emerged as a promising alternative due to its abundance, renewability, and carbon-neutral footprint. However, its economic feasibility remains a major obstacle owing to high production costs, particularly those associated with low ethanol titers and the energy-intensive distillation process costs for low titers. High-solid loading processes (≥15% w/w or w/v) have demonstrated potential to overcome these limitations by minimizing water and solvent consumption, enhancing sugar concentrations, increasing ethanol titers, and lowering downstream processing cost. Nevertheless, high-solid loading also introduces operational bottlenecks, such as elevated viscosity, poor mixing, and limited mass and heat transfer, which hinder enzymatic hydrolysis efficiency. This review critically examines emerging pretreatment and enzymatic hydrolysis strategies tailored for high-solid loading conditions. It also explores techniques that improve sugar yields and conversion efficiency while addressing key technical barriers, including enzyme engineering, process integration, and optimization. By evaluating these challenges and potential mitigation strategies, this review provides actionable insights to intensify lignocellulosic ethanol production and advance the development of scalable, cost-effective biorefinery platforms. Full article