Search Results (352)

The convergence of food insecurity, water scarcity, and environmental degradation has intensified the global search for sustainable agricultural models. Integrated Microalgal–Aquaponic Systems (IAMS) have emerged as a novel multi-trophic platform that unites aquaculture, hydroponics, and microalgal cultivation into a closed-loop framework for resource-efficient food production and water recovery. This critical review synthesizes empirical findings and engineering advancements published between 2008 and 2024, evaluating IAMS performance relative to traditional agriculture and recirculating aquaculture systems (RAS). Reported under controlled laboratory and pilot-scale conditions, IAMS have achieved nitrogen and phosphorus recovery efficiencies exceeding 95% while potentially reducing water consumption by up to 90% compared to conventional farming. The integration of microalgal photobioreactors enhances nutrient retention, may contribute to internal carbon capture, and enables the generation of diversified co-products, including biofertilizers and protein-rich aquafeeds. Nevertheless, significant barriers to commercial scalability persist, including the biological complexity of maintaining multi-trophic synchrony, high initial capital expenditure (CAPEX), and regulatory ambiguity regarding the safety of waste-derived algal biomass. Technical challenges such as photobioreactor upscaling, biofouling control, and energy optimization are critically discussed. Finally, the review evaluates the alignment of IAMS with UN Sustainable Development Goals 2, 6, and 13, and outlines future research priorities in techno-economic modeling, automation, and policy development to facilitate the transition of IAMS from pilot-scale innovations to viable industrial solutions. Full article

The massive influx of pelagic Sargassum in the Caribbean poses a serious environmental, social, and economic problem, as the stranded biomass is often treated as waste and deposited in landfills. This literature review synthesizes recent research highlighting its potential for valorization in various industries, turning this challenge into an opportunity. Sargassum has low levels of protein and lipids. Still, it is particularly rich in carbohydrates, such as alginates, fucoidans, mannitol, and cellulose, as well as secondary metabolites, including phenolic compounds, flavonoids, pigments, and phytosterols with antioxidant and bioactive properties. These biochemical characteristics allow for its application in renewable energy (bioethanol, biogas, biodiesel, and combustion), agriculture (fertilizers and biostimulants), construction (composite materials, cement additives, and insulation), bioremediation (adsorption of heavy metals and dyes), and in the health sector (antioxidants, anti-inflammatories, and pharmacological uses). A major limitation is its high bioaccumulation capacity for heavy metals, particularly arsenic, which increases environmental and health risks and limits its direct use in food and feed. Therefore, innovative pretreatment and bioprocessing are essential to mitigate these risks. The most promising approach for its utilization is a biorefinery model, which allows for the sequential extraction of multiple high-value compounds and energy products to maximize benefits, reduce costs, and sustainably transform Sargassum from a coastal pest into a valuable industrial resource. Full article

Tuna-processing facilities produce substantial amounts of concentrated organic residues and sludges containing high levels of proteins, lipids, and nitrogen, which are not easily handled by conventional waste treatment methods. In this work, the anaerobic digestion (AD) performance of tuna-processing by-products (TPB1–2) and associated wastewater sludges (TWS1–3) was investigated using a combination of biochemical methane potential (BMP) tests, theoretical methane yield calculations based on the Buswell–Boyle equation, semi-continuous mono-digestion experiments, and 16S rRNA gene-based microbial analyses. Among the evaluated materials, TWS2 produced the highest methane yield (554.6 N mL CH₄/g VS) and, when its annual production volume was taken into account, showed the greatest estimated energy recovery (approximately 1.88 × 10⁶ kWh per year). By contrast, TWS3 exhibited the lowest methane yield (239.8 N mL CH₄/g VS), which was attributed to the presence of lignocellulosic sawdust and its limited biodegradability. TWS1 showed a moderate level of performance, with an estimated biodegradability of 62.3%, which may have been influenced by the addition of ferric salts and polymeric coagulants during sludge conditioning. In the semi-continuous digestion experiments, reactors that were initiated under relatively high total ammonia nitrogen (TAN) concentrations achieved stable operation within a shorter period, with the acclimation phase reduced by approximately one hydraulic retention time. These trends were supported by the microbial community data, where an increase in Bacillota-associated families, such as Tissierellaceae and Streptococcaceae, was detected along with a clear shift in dominant methanogens from Methanothrix to the more ammonia-tolerant Methanosarcina. Taken together, it is suggested that, when ammonia levels are appropriately managed, mono-digestion of tuna-processing sludges can be operated at a moderate organic loading rate. The process stabilization and energy recovery in nitrogen-rich industrial wastes are closely linked to gradual microbial adaptation rather than immediate improvements in methane yield. Full article

African catfish (Clarias gariepinus, AC) is one of the most widely farmed freshwater fish species in Central Europe. Processing operations generate up to 55% by-products (BPs), predominantly carcasses rich in proteins, lipids, and minerals. This study develops a comprehensive valorization process for ACBPs to recover gelatin, protein hydrolysate, fish oil, and pigments. The processing protocol consisted of sequential washing, oil extraction, demineralization, and biotechnological treatment to disrupt the collagen quaternary structure. A two-factor experimental design was employed to optimize the processing conditions. The factors included the extraction temperatures of the first (35–45 °C) and second fraction (50–60 °C). We hypothesized that enzymatic conditioning, combined with sequential hot-water extraction, would yield gelatin with properties comparable to those of mammalian- and fish-derived gelatins, while enabling a near-zero-waste process. The integrated process yielded 18.2 ± 1.2% fish oil, 9.8 ± 2.1% protein hydrolysate, 1.7 ± 0.7% pigment extract, and 25.3–37.8% gelatin. Optimal conditions (35 °C/60 °C) produced gelatin with gel strength of 168.8 ± 3.6 Bloom, dynamic viscosity of 2.48 ± 0.02 mPa·s, and yield of 34.76 ± 1.95%. Life cycle assessment (LCA) identified two primary environmental hotspots: water consumption and energy demand. This near-zero-waste biorefinery demonstrates the potential for comprehensive valorization of aquaculture BPs into multiple value-added bioproducts. Full article

Sacha inchi (P. volubilis L.), an ancient oilseed crop native to the Amazon, is gaining attention for its high nutritional value particularly due to its ω-3-, -6-, -9-rich oil. However, most research has focused mainly on oil characterization, neglecting the potential of its by-products, such as the Sacha inchi oil-press cake (i.e., the solid residue after oil extraction). This study explores the chemical composition of Sacha inchi oil press-cake powder, focusing on fatty acid and amino acid profiles, antinutrient factors, total phenolic content, antioxidant activity, and the bioactivity of its extracts on cellular models. Fatty acid analysis revealed a high proportion of polyunsaturated fatty acids, especially α-linolenic acid (42.52%), making it a valuable resource for health-promoting applications. The protein content was also significant (41.86%), with a balanced amino acid composition, including essential amino acids such as leucine, valine, and isoleucine, which are vital for muscle protein synthesis and energy metabolism, in food and/or feed applications. Antinutritional factors were detected, including saponins (1050.1 ± 1.1 mg/100 g), alkaloids (2.1 ± 0.5 mg/100 g), and tannins (6.2 ± 0.9 mg/100 g). While these phytotoxins could limit their use in food applications, their potential antimicrobial activity highlights promising pharmacological opportunities. Total phenolic content (TPC) and antioxidant activity (AO) were evaluated using two extract mixtures differing in composition and polarity, with the acetone/water/acetic acid solvent (80/19/1 v/v/v) showing the highest antioxidant properties. The extract obtained showed cytotoxic effects against Panc-1 cancer cells, highlighting its potential in nutraceutical and pharmaceutical applications. This study underscores the unexploited potential of Sacha inchi by-products, such as the oil press-cake, as a sustainable resource of bioactive compounds for functional products, supporting circular bio-economy strategies by plant-based waste and local biodiversity valorization. Full article

Due to global increases in poultry meat and egg production, consumers request sustainable agricultural practices, requiring alternative solutions for future feeding. Global egg production increased by over 41% between 2000 and 2020, from 51 to 87 million tonnes, at an average increasing rate of 3%. Similarly, the production of poultry meat reached 145 million tonnes in 2023 and continues to increase, which amplifies the pressure on sustainable alternative feed solutions. Commercial poultry diets are typically based on a cereal (corn or wheat) as an energy source and a quality protein source, especially soybean meal (SBM), to provide essential amino acids. Soybean production is associated with deforesting and land use in several countries, sensitiveness to supply chains and price volatility. As a response to these challenges over the last decade, research and commercial innovation have intensively focused on alternative and novel feed resources that can be integrated into both broiler and layer diets. Some future candidate ingredients are insect meal, algae, agro-industrial by-products such as distiller’s dried grains with solubles (DDGS), brewery spent grains (BSG) and fermented feedstuffs (oilseed cakes/meals). Literature data showed that moderate inclusion of these alternative ingredients can be partly integrated in poultry diets, without compromising egg or meat quality. In some cases, studies showed improvements of productive performances and specific quality traits (yolk color, fatty acids and antioxidant compounds), offering potential to valorize waste streams, improve local circularity and provide functional ingredients for animals and humans. However, challenges still remain, especially in terms of nutrient variability, digestibility limitations, higher processing costs and still-evolving regulations which constrain mainstream adoption of some of these potential future alternatives. Full article

Background: Nigeria faces a severe child malnutrition crisis, with approximately 1 million severe cases reported for 2025. This burden positions Nigeria among the top countries globally for stunting and wasting in under-fives, exacerbated by factors like food insecurity, flooding, and conflict—particularly in the northern part. This study investigated the development and assessment of Ready-to-Use Therapeutic Foods (RUTF) produced from locally sourced ingredients in Kano State, Nigeria, targeting child malnutrition. Methods: Three distinct RUTF formulations were prepared using rice, wheat, groundnut, and soybean, with raw materials purchased from local markets and processed into blends. Proximate, vitamin (A, C, and E), and mineral (zinc, iron, potassium, magnesium, calcium, and sodium) compositions were measured following the Association of Official Analytical Chemists’ (AOAC) standard procedures. Sensory evaluation using a 9-point hedonic scale assessed taste, aroma, flavour, appearance, and overall acceptability. Results: Notable variations were observed among the samples. Blend A exhibited the highest energy (563.08 kcal/100 g), carbohydrate (46.57%), fat (35.84%), and vitamin E (9.29 mg/100 g) content. Blend B was highest in protein (16.71%), iron (2.40 mg/100 g), calcium (21.05 mg/100 g), and vitamin A (15.89 µM). Blend C contained the most potassium (61.65 mg/100 g) and vitamin C (11.70 mg/100 g), with moderate levels of other nutrients. Sensory ratings showed no significant (p < 0.05) differences among the parameters. Conclusions: The nutrient composition and acceptability of RUTF blends suggest that affordable, effective dietary solutions can be produced using local crops. These findings support the potential for locally formulated RUTFs to contribute to reducing child malnutrition in low-resource settings with further enhancements. Full article

The brewing industry produces a large amount of byproducts, primarily brewery spent grain (BSG), which mainly consists of carbohydrates, proteins, and lipids. The different fractions isolated and extracted from BSG have significant potential for waste valorization and could be used as functional products or food ingredients. In this study, specific BSG-derived fractions (Hemicellulose A, Hemicellulose B, and oligosaccharides) were isolated and characterized to evaluate their potential applications. Thermogravimetric analysis data showed that the residue at 600 °C for various fractions is approximately 20% under N₂, compared to 10% in air for BSG fractions. The rheological properties of Hemicellulose A and Hemicellulose B fractions from brewers’ spent grain (BSG) exhibit high viscosity, suggesting a strong dependence on molecular weight. This characteristic implies that their elevated molecular size may play a key role in their capacity to form gels, potentially enhancing their functionality in applications requiring thickening or structural integrity. Among the BSG fractions, Hemi. It had a viscosity of >102 mPa s⁻¹ at a 3% (w/v) concentration, which was higher than Hemi B and oligosaccharides at the same concentration. The zeta potential of BSG fractions at various pH and concentrations was measured to assess the effects of pH and concentration. Additionally, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) revealed the surface morphology and composition of each fraction. The highest Phosphorus (P) (%) was found on the surfaces of both Hemi B and the hexane-extracted BSG. The surface elements of each fraction primarily included C, O, N, P, Ca, and Mg. Full article

Biochar is one of the most promising crop straw utilization pathways. However, its capacity for adsorbing heavy metals is limited, and there is a potential risk of secondary pollution, highlighting the importance of developing efficient and environmentally friendly bio-modification methods. Here, we utilized glomalin-related soil protein (GRSP), a byproduct from arbuscular mycorrhizal fungi, to modify straw biochar, developing a novel composite material and systematically evaluating its performance in removing copper ion (Cu²⁺) from aqueous solutions. Biochar samples derived from maize, wheat, and rice straw were prepared at three pyrolysis temperatures (300 °C, 500 °C, and 700 °C), followed by surface functionalization with GRSP to produce GRSP-modified straw biochar for Cu²⁺ adsorption experiments. The results demonstrated that the abundant functional groups (e.g., amino and carboxyl groups) in GRSP and the porous structure of the straw biochar exhibited a significant synergistic effect, enhancing the adsorption capacity for Cu²⁺. Notably, the GRSP-modified wheat straw biochar prepared at 700 °C achieved an adsorption capacity of 193.2 mg g⁻¹ for Cu²⁺, representing a 76% improvement over the unmodified material. Fourier transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy revealed that hydroxyl, carboxyl, and ether groups served as key adsorption sites for Cu²⁺, while the hydrophobic-acid precipitation characteristics of GRSP further enhanced the material’s recoverability. By systematically characterizing the material’s microstructure and its adsorption behavior toward Cu²⁺, this study elucidated the role of critical functional groups in the adsorption mechanism. This work not only offers a low-carbon and efficient strategy for agricultural waste valorization and heavy metal pollution control, but also advances the mechanistic understanding of “bio-abiotic” synergy in environmental remediation. Full article

In recent years, concerns about sustainability in livestock farming have been raised. The livestock sector is accused of substantial greenhouse gas emissions, environmental pollution (i.e., wastewater with high COD and rich in N and P that can pollute freshwater and cause eutrophication), and resource consumption. The use of fossil resources to produce synthetic fertilizers is the major source of pollution indirectly attributable to livestock farming. However, the polluting load of the livestock sector can be used to produce energy and materials, increasing its sustainability. The scope of this work was to critically review the methods of management and valorization of waste from the livestock sector (slurry, manure, abattoir wastewater, slaughterhouse waste, and aquaculture waste). The various technologies for energy valorization (i.e., bio-H₂ and bio-CH₄) will be represented. The perspectives and challenges for the exploitation of these wastes to produce high-added-value molecules, extraction of bioactive molecules, alternative proteins, biofertilizers, and biopolymers will also be discussed in view of enhancing sustainability. Examples of possible large animal waste-based integrated biorefineries have also been proposed. Full article

Background/Objectives: Protein-energy wasting (PEW) affects up to 75% of hemodialysis (HD) patients, yet adherence to oral nutritional supplements (ONSs) remains poorly understood. This study evaluated ONS adherence patterns, associated socio-demographic and psychological factors, and clinical outcomes over 24 months in chronic HD patients. Methods: A 24-month prospective study was conducted in 101 HD patients. Adherence was assessed using the 4-item Morisky Medication Adherence Scale (MMAS-4), and depressive symptoms with the Beck Depression Inventory (BDI). Nutritional status was evaluated using the Malnutrition–Inflammation Score (MIS) and anthropometric measurements. Laboratory markers were obtained. Individualized nutritional education was provided at each visit. Results: Regular ONS use was reported in 50.5% of patients. High adherence (MMAS-4 = 0) was observed in 36.6% of the cohort. Forgetfulness (45.3%) and adverse effects (34.4%) were the most common obstacles. Adherence was significantly associated with sex (p = 0.007), with men more frequently demonstrating low adherence. Education level showed a weak, but significant positive correlation with MMAS-4 score (Spearman’s ρ = 0.25, p = 0.018), indicating slightly lower adherence among more educated patients. MMAS-4 and BDI scores were positively correlated (Spearman’s ρ = 0.25, p = 0.04), indicating that greater depressive symptom burden was associated with lower adherence. Regular ONS users demonstrated improved nutritional status (lower MIS; 9 vs. 7, p < 0.001), higher hemoglobin (106 vs. 114 g/L, p = 0.03), and increased mid-upper arm circumference (MUAC; 26 vs. 28 cm, p = 0.02). Lean tissue mass was preserved over time (p = 0.009). However, individualized education had limited effect on patients with initially low adherence. Individualized nutritional education was associated with improved acceptance and implementation of recommendations. Over two years of follow-up, nutritional education was associated with preserved lean and fat tissue index (LTI, p = 0.009; FTI, p = 0.08), reductions in interdialytic weight gain, and significant improvements in MUAC, waist circumference, and scapular skinfold thickness (p = 0.03; p < 0.001; p = 0.02). Prealbumin and hemoglobin levels also increased significantly (p = 0.02; p = 0.04). However, education alone was insufficient for certain subgroups, particularly older patients and those initially classified as non-adherent. During follow-up, 17 patients died. Lower MUAC (OR = 2.97, 95% CI: 1.45–6.08) and triceps skinfold thickness (OR = 1.37, 95% CI: 1.12–1.68) were the strongest independent predictors of mortality. Conclusions: Adherence to ONSs remains suboptimal in HD patients. Individualized nutritional education was associated with improved adherence and nutritional status in some subgroups but may be insufficient in older or initially non-adherent patients. Simple anthropometric markers are strong mortality predictors and may offer practical value for routine monitoring. Full article

Dark fermentation of food waste for biohydrogen production can simultaneously achieve waste resource utilization and clean energy production. However, the widespread application of this technology remains constrained by challenges such as low substrate hydrolysis efficiency and suboptimal metabolic performance of functional microorganisms. This study evaluated the synergistic enhancement of biohydrogen production from food waste through dark fermentation by integrating thermal–alkaline (TA) pretreatment with varying concentrations (50, 100, 150, and 200 mg/L) of nickel–cobalt oxide nanoparticles (NiCo₂O₄ NPs), and the underlying mechanisms involved were systematically elucidated. The results demonstrated that individual TA pretreatment (pH 11, 70 °C, 1 h) and TA coupled with NiCo₂O₄ NPs (100 mg/L) significantly (p < 0.01) enhanced the cumulative biohydrogen yields of the food waste dark fermentation by 20.89% and 35.76%, respectively. Mechanism research revealed that TA pretreatment effectively facilitated the dissolution and hydrolysis of macro-molecular organics such as polysaccharides and proteins, thereby enhancing the bio-accessibility of fermentation substrates. The introduction of NiCo₂O₄ NPs further intensified the microbial biohydrogen-producing metabolism by augmenting enzymatic activity and enriching functional bacteria. NiCo₂O₄ NPs significantly (p < 0.001) enhanced the overall activity of hydrogenase by 95.10% compared to the control group (CG) by providing the cofactor of hydrogenase and accelerating electron transfer. Additionally, this synergistic strategy significantly (p < 0.01) increased the activities of hydrolases (e.g., protease and α-glucosidase), as well as key enzymes in acetate-type and butyrate-type fermentation pathways (e.g., acetate kinase and butyrate kinase), and enriched the biohydrogen-producing microbial community centered on Clostridium_sensu_stricto_1. This study systematically elucidated the synergistic strategy of TA pretreatment and NiCo₂O₄ NPs, which achieved dual-pathway reinforcement from substrate degradability to microbial metabolic activity. The findings are expected to provide theoretical support for developing efficient biohydrogen production technology from perishable organic solid waste. Full article

Background/Objectives: Protein–energy wasting (PEW) is a common complication in patients with chronic kidney disease (CKD) receiving renal replacement therapy by dialyses. This condition is associated with higher morbidity, mortality, and poorer quality of life. The aim of this systematic review was to evaluate the effectiveness of different nutritional strategies—such as oral nutritional supplements and intra-dialytic parenteral nutrition—in improving the nutritional status of these patients. Methods: A systematic review was carried out in accordance with the PRISMA statement. Searches were performed in PubMed, BVS, and Scopus between January and March 2025. Randomised or controlled clinical trials published in English or Spanish, available in full text, involving adults on haemodialysis (HD) or peritoneal dialyses (PD) were included. Fourteen studies met the inclusion criteria. Results: The nutritional interventions assessed produced consistent benefits in biochemical markers (e.g., serum albumin), muscle mass, inflammatory indices, and perceived quality of life. Intra-dialytic supplementation and multidisciplinary management were particularly effective in patients with moderate-to-severe malnutrition. Conclusions: Malnutrition is frequent and clinically significant in dialyses patients. Nutritional strategies—including oral supplementation, IDPN, and personalised counselling—effectively prevent and treat PEW. Early, tailored, evidence-based, and multidisciplinary implementation could decisively improve clinical prognosis and quality of life in this population. Full article

A sustainable economy and the drive to reduce agro-industrial waste worldwide motivate the increased interest in alternative uses of traditionally cultivated plants such as tobacco. Tobacco seeds are an underutilized resource with enormous potential for application in various areas of human life. The present study aims to characterize the phytochemical composition and nutritional potential of Oriental tobacco seeds grown in Bulgaria, in order to support their possible application in areas outside the tobacco industry. Two Oriental tobacco varieties (“Krumovgrad 90” and “Krumovgrad 58”) from three production regions were explored and comparatively evaluated in terms of their physical and chemical indicators, determined by standardized methods. The results showed high protein (22.57–23.84%) and energy content (482–531 kcal/100 g), combined with relatively low carbohydrate levels (3.79–4.03%) and the presence of bioactive compounds, such as polyphenols (288–357 mg GAE/100 g). The seeds contained significant amount of oil (36.31–39.24%), of which the fatty acid profile included 16 identified components, with linoleic (72.0–74.4%), oleic (11.2–13.5%), palmitic (9.6–10.2%), and stearic (1.8–2.5%) acids taking the greatest share. The sterol fraction was dominated by β-sitosterol (43.5–46.8%), followed by sitostanol, campesterol and stigmasterol, with a stable distribution between the samples. The main tocol was γ-tocotrienol (56.5–61.4%), with α-tocotrienol being detected only in one of the varieties (“Krumovgrad 58”, 13.3%). The phospholipid fraction showed variations between the samples, with a dominant presence of phosphatidylinositol (18.0–20.4%). The results from the study confirmed the tangible potential of tobacco seeds as a source of biologically active substances in the development of functional foods and dietary supplements. Full article

Anaerobic digestion is a well-known technology for renewable energy generation. Its efficiency depends on the substrate composition and its biodegradability. Microalgae are considered a promising feedstock due to their rapid growth, high protein and lipid content, and potential for wastewater treatment. However, the mono-digestion is often limited by a low carbon-to-nitrogen (C/N) ratio and a recalcitrant cell wall structure. This study evaluated the potential of co-digesting microalgal biomass with bakery waste under batch conditions. Two types of bakery residues (stale wheat bread and stale wheat rolls), were tested. Each was added to the microalgal biomass at proportions of 25%, 50%, and 75% based on volatile solids (VS). The experiment was carried out in a semi-technical anaerobic digester under mesophilic conditions. During the anaerobic digestion, the biogas volume, gas composition, and the energy potential of the substrates were analysed. The highest biogas yield (494.34 L·kg⁻¹ VS) was obtained from the mixture of microalgae and 75% bread. Although mono-digestion of microalgal biomass resulted in the highest methane concentration, the differences compared to co-digested samples were not significant. The lowest hydrogen sulphide concentration (234.20 ppm) was measured in the 25% rolls variant, while the control sample (100% microalgae) showed the highest H₂S levels. From an energy perspective, the most beneficial result was obtained with the addition of 75% bread. Full article