Search Results (208)

The utilisation of agrifood waste ashes has the potential to enhance the nutrient content of cereal crops, thereby optimising both yield and grain quality. This study investigated rye grain composition, the fermentation efficiency, and volatile compounds in mashes made from crops fertilised with agrifood waste ashes derived from the combustion of corn cob, wood chips, and biomass with defecation lime. The ashes were applied at 2, 4, and 8 t/ha, separately and as mixtures of corn cob (25%) with wood chips (75%) and corn cob (50%) with biomass and defecation lime (50%). Rye mashes were prepared using the pressureless starch liberation method. The starch content in the majority of the rye grains was comparable to the control sample (57.12 g/100 g). The range of ethanol concentrations observed in the fermented mashes was from 55.55 to 68.12 g/L, which corresponded to fermentation yields of 67.25–76.59% of theoretical. The lowest fermentation yield was exhibited by the mash derived from rye cultivated on soil fertilised with a 50:50 mixture of ashes from corn cob and biomass with defecation lime at 8 t/ha. This mash contained more than double the acetaldehyde concentration and total aldehyde content compared to the other samples. These findings demonstrate the potential of using waste biomass ash as a source of macro- and microelements for rye cultivation, enabling the production of agricultural distillates. To ensure high fermentation efficiency and low aldehyde levels, ash dosage and composition need to be established based on experimental optimisation. Full article

In recent decades, the rapid expansion of the food processing industry has led to significant losses and waste, with the fruit and vegetable sector among the most affected. According to the Food and Agriculture Organization of the United Nations (FAO), losses in this category can reach up to 60%. Vegetable waste includes edible parts discarded during processing, packaging, distribution, and consumption, often comprising by-products rich in bioactive compounds such as polyphenols, carotenoids, dietary fibers, vitamins, and enzymes. The underutilization of these resources constitutes both an economic drawback and an environmental and ethical concern. Current recovery practices, including their use in animal feed or bioenergy production, contribute to a circular economy but are often limited by high operational costs. In this context, fermentation has emerged as a promising, sustainable approach for converting vegetable by-products into value-added food ingredients. This process improves digestibility, reduces undesirable compounds, and introduces probiotics beneficial to human health. The present review examines how fermentation can improve the nutritional, sensory, and functional properties of plant-based foods. By presenting several case studies, it illustrates how fermentation can effectively valorize vegetable processing by-products, supporting the development of novel, health-promoting food products with improved technological qualities. Full article

In recent years, great attention has been paid to second-generation (from agricultural and industrial wastes) lactic acid (LA) production. In the present study, the possibility of two Lactiplantibacillus plantarum strains, namely 53 and 2HS, to produce LA from waste materials was investigated. Distiller’s dried grains with solubles (DDGS), spent coffee grounds (SCG), wood chips, and cheese whey were used as substrates after pretreatment, and the results were compared with those with lactose as a carbon source. Both strains were capable of assimilating sugars from all waste materials. Nearly 20 g/L LA from 23 g/L reducing sugars (RS) obtained from DDGS, 22 g/L LA from 21 g/L RS from SCG, and 22 g/L LA from 21 g/L whey lactose were produced compared to 22 g/L LA obtained from 22 g/L lactose monohydrate in the fermentation broth. The wood chip hydrolysate (WH) contains only 10 g/L RS, and its fermentation resulted in the production of 5 g/L LA. This amount is twice as low as that produced from 11 g/L lactose monohydrate. A mathematical model was constructed based on the Compertz and Luedeking–Piret equations. Full article

This study proposes an integrated framework for sustainable tropical agriculture by combining biochemical waste valorization with spatial carbon footprint estimation in ‘Phulae’ pineapple production. Peel and eye residues from fresh-cut processing were enzymatically converted into rare sugar, achieving average conversion efficiencies of 35.28% for peel and 37.51% for eyes, with a benefit–cost ratio of 1.56 and an estimated unit cost of USD 0.17 per gram. A complementary zero-waste pathway produced functional gummy products using vinegar fermented from pineapple eye waste, with the preferred formulation scoring a mean of 4.32 out of 5 on a sensory scale with 158 untrained panelists. For spatial carbon modeling, the Bare Land Referenced Algorithm (BRAH) and Otsu thresholding were applied to multi-temporal Sentinel-2 and THEOS imagery to estimate plantation age, which strongly correlated with field-measured emissions (r = 0.996). This enabled scalable mapping of plot-level greenhouse gas emissions, yielding an average footprint of 0.2304 kg CO₂ eq. per kilogram of fresh pineapple at the plantation gate. Together, these innovations form a replicable model that aligns tropical fruit supply chains with circular economy goals and carbon-related trade standards. The framework supports waste traceability, resource efficiency, and climate accountability using accessible, data-driven tools suitable for smallholder contexts. By demonstrating practical value addition and spatially explicit carbon monitoring, this study shows how integrated circular and geospatial strategies can advance sustainability and market competitiveness for the ‘Phulae’ pineapple industry and similar perennial crop systems. Full article

Agriculture and its related industries produce annually a vast amount of byproducts and waste which comprise a large proportion of global waste. Only a small percentage is managed with environmentally acceptable procedures, while a large proportion is either incinerated or discarded into nearby open fields, causing serious environmental burdens. Since these byproducts exhibit a rich nutritional and phytochemical content, they may be considered as raw materials for various industrial applications, initiating the need for the development of sustainable and eco-friendly methods for their valorization. Among the various methods considered, Solid-State Fermentation (SSF) constitutes an intriguing eco-friendly bioprocess, being suitable for water-insoluble mixtures and providing products with improved stability and depleted catabolic suppression. Thus, there are several literature studies highlighting the aspects and efficacy of SSF for improving the nutritional and phytochemical contents of diverse agro-industrial waste. The review herein aspires to summarize these literature results with a special focus on the enhancement of their antioxidant potency. For this purpose, specific keywords were used for searching multiple scientific databases with an emphasis on the most recent studies and higher impact journals. The presented data establish the usefulness and efficacy of the SSF bioprocess to obtain fermentation products with enhanced antioxidant profiles. Full article

Various pretreatment methods for the valorization of sunflower husks (SHs) for H₂ gas generation through fermentation by Escherichia coli were investigated. We analyzed thermal treatment (TT), acid hydrolysis (AH), and alkaline hydrolysis (AlkH) at different substrate concentrations (50 g L⁻¹, 75 g L⁻¹, 100 g L⁻¹, and 150 g L⁻¹) and dilution levels (undiluted, 2× diluted, and 5× diluted). A concentration of 75 g L⁻¹ SH that was acid-hydrolyzed and dissolved twice in the medium yielded optimal microbial growth, reaching 0.3 ± 0.1 g cell dry weight (CDW) L⁻¹ biomass. The highest substrate level enabling effective fermentation was 100 g L⁻¹, producing 0.37 ± 0.13 (g CDW) × L⁻¹ biomass after complete fermentation, while 150 g L⁻¹ exhibited pronounced inhibitory effects. It is worth mentioning that the sole alkaline treatment was not optimal for growth and H₂ production. Co-fermentation with glycerol significantly enhanced both biomass formation (up to 0.42 ± 0.15 (g CDW) × L⁻¹)) and H₂ production. The highest H₂ yield was observed during batch growth at 50 g L⁻¹ SH hydrolysate with 5× dilution, reaching up to 5.7 mmol H₂ (g sugar)⁻¹ with glycerol supplementation. This study introduces a dual-waste valorization strategy that combines agricultural and biodiesel industry residues to enhance clean energy generation. The novelty lies in optimizing pretreatment and co-substrate fermentation conditions to maximize both biohydrogen yield and microbial biomass using E. coli, a widely studied and scalable host. Full article

Plant Parasitic Nematodes (PPNs) are a major problem in agriculture. Damage caused by PPNs has been estimated at USD 80–157 billion annually. The estimates could be even worse in the future in the context of a growing world population in a climate change scenario and with the removal/reduction in the use of some nematodicides due to the strong ecological impact. Biocontrol Agents (BCAs) currently constitute only 8.8% of the general pesticide market. With a view to an ecological transition, the transition from pesticides to biopesticides represents an important challenge that appears necessary not only for organic farming, but also in so-called integrated agriculture. Among the possible BCAs, microorganisms, and in particular yeast, which enjoys the GRAS (Generally Recognized As Safe) status, have the advantage of being able to be produced on a large scale by fermentation on waste substrates at low cost. In this paper, as proof of concept we constructed yeast strains expressing short hairpin RNAs (shRNAs) targeting the daf-16 gene in C. elegans. We demonstrate that oral ingestion of yeast cells expressing DAF16 shRNA is efficient in lowering daf-16 expression and lifespan, suggesting a sustainable RNA interference-based strategy to inhibit the development of PPNs. Full article

Anaerobic acidogenic fermentation presents a promising approach for sustainable carbon emission mitigation in livestock waste management, addressing critical environmental challenges in agriculture. This study systematically investigated the synergistic effects of composting-assisted pretreatment coupled with micro-aeration and methanogenesis suppression to enhance volatile fatty acid (VFA) production from swine manure supplemented with wheat straw, valorizing agricultural waste while reducing greenhouse gas emissions. The experimental protocol involved sequential optimization of pretreatment conditions (12 h composting followed by 10 min thermal pretreatment at 85 °C), operational parameters (300 mL micro-aeration and 30 mmol/L 2-bromoethanesulfonate (BES) supplementation), and their synergistic integration. The combined strategy achieved peak VFA production (5895.92 mg/L, p < 0.05), with butyric acid constituting the dominant fraction (2004.42 mg/L, p < 0.05). Enzymatic analysis demonstrated significantly higher activities of key hydrolytic enzymes (protease, α-glucosidase) and acidogenic enzymes (butyrate kinase, acetate kinase) in the synergistic treatment group compared to individual BES-supplemented or micro-aeration-only groups (p < 0.05). This integrated approach provides a technically feasible and environmentally sustainable pathway for circular resource recovery, contributing to low-carbon agriculture and waste-to-value conversion. Full article

Anaerobic digestion for biogas production represents a crucial approach to achieving the high-value utilization of agricultural solid waste. The adoption of multi-material co-digestion offers a viable solution to overcome the inherent constraints associated with single-substrate digestion, thereby significantly enhancing the efficiency of resource utilization. This study explored a co-digestion system using dairy manure and cucumber vines as substrates, uncovering how total solids (TS) influence the methane yield and microbial community characteristics. All treatments exhibited swift methane fermentation, with daily production initially increasing before declining. Cumulative methane production increased with the increasing TS contents. These results may be linked to pH value and the concentration of volatile fatty acids (VFAs). Except for the 6% TS treatment, digesters across different TS levels maintained a favorable final pH of 7.4–8.4, while VFA concentrations exhibited a downward trend as TS contents increased. The treatment with the highest TS concentration (25%) demonstrated superior performance, achieving the maximum volumetric methane yield. This yield was 1.6 to 9.1 times higher than those obtained at low (6–10%) and medium (12–18%) TS concentrations. Microbial community analysis revealed that during the peak methane production phase, Firmicutes and Methanoculleus were the predominant bacterial and archaeal phyla, respectively. The microbial community structure changed with different TS levels. This study offers valuable scientific insights for enhancing biogas production efficiency in co-digestion systems. Full article

Electrolytic manganese residue (EMR), an acidic by-product from manganese production, presents dual challenges of environmental pollution and resource waste. This study developed a silicon–manganese organic compound fertilizer (SMOCF) via the aerobic fermentation of EMR supplemented with bagasse, molasses, and activated sludge. The physicochemical analysis revealed that the EMR’s composition was dominated by silicon (7.1% active Si), calcium, sulfur, and trace elements. Critical parameters during composting—including water-soluble Mn (1.48%), organic matter (8.05%), pH (7.4), moisture (20.28%), and germination index (GI = 87.78%)—met organic fertilizer standards, with the GI exceeding the phytotoxicity threshold (80%). The final SMOCF exhibited favorable agronomic properties: neutral pH, earthy texture, and essential macronutrients (1.36% K, 1.11% N, 0.48% P). Heavy metals (As, Cd, Cr, Pb) in the SMOCF predominantly existed in stable residual forms, with total concentrations complying with China’s organic fertilizer regulations (GB/T 32951-2016). The ecological risk assessment confirmed a minimal mobilization potential (risk assessment code < 5%), ensuring environmental safety. This work demonstrates a circular economy strategy to repurpose hazardous EMRs into agriculturally viable fertilizers, achieving simultaneous pollution mitigation and resource recovery. The optimized SMOCF meets quality benchmarks for organic fertilizers while addressing heavy metal concerns, providing a scalable solution for industrial EMR valorization. Further studies should validate the field performance and long-term ecological impacts to facilitate practical implementation. Full article

As a typical agricultural waste, the resource utilization of corn stover (CS) plays a crucial role in the coordinated optimization of ecological and economic benefits. In order to enhance the utilization of CS resources, Lentilactobacillus (L.) buchneri (LB) and different proportions of Artemisia argyi (AA) were added to CS to investigate the impact of additives on the fermentation quality and aerobic stability of corn stover silage (CSS). This study revealed that the separate addition of AA or LB in CS effectively improved the silage quality and aerobic stability. Specifically, LB exhibited the lowest pH value of 3.72 at 90 d of fermentation, while the NH₃-N content was 0.07 g/kg DM during the anaerobic fermentation stage and 0.19 g/kg DM during the aerobic exposure stage (p < 0.05). Mixing 30% AA increased the lactic acid content, lowered the pH, maintained a higher relative abundance of Lactobacillus, and reduced mycotoxin levels. In terms of aerobic stability, all AA-treated groups demonstrated superior performance compared to the LB treatment. Additionally, it was observed, that in the 30% AA group, Candida exhibited the highest relative abundance. Importantly, the addition of AA upregulated carbohydrate metabolism and lipid metabolism during the ensiling process, and their relative abundances remained high during aerobic exposure. Fully utilizing CS resources as feed to provide fiber and nutrients for ruminants can not only reduce the pressure on forage demand but meet the development needs of “grain-saving” animal husbandry, which is conducive to solving the contradictions of “human–animal competition for food” and “human animal competition for land”. Full article

This study evaluates the effects of solid-state fermentation inoculated with Aspergillus spp. on the nutritional profile of selected agro-industrial by-products (AIBPs: cowpea shell, groundnut shell, soybean hull, and maize shaft). These AIBPs were assessed as potential feedstuffs in weaner rabbit diets, which often exhibit digestive disorders when introduced to highly lignified feed ingredients. The AIBPs were milled to a particle size of 2 mm, sterilized, and subjected to fermentation with Aspergillus spp. under microaerophilic conditions at 28 ± 2 °C for 10 days. Samples (four replicates per treatment) were analyzed for chemical constituents (mineral and proximate composition, anti-nutritional factors, and fibre fractions) before and after fermentation. Digestible energy and digestibility coefficient of gross energy were calculated. Data were subjected to two-way analysis of variance (ANOVA). There was an increase (p < 0.05) in mineral profile, proximate composition, digestible energy, digestibility coefficient of gross energy, and dry matter, with a reduction (p < 0.05) in crude fibre, fibre fractions, and anti-nutritional factors. It was concluded that fermentation with Aspergillus spp. improved the nutritional value of the selected agro-industrial by-products. Therefore, fermented materials possess a better nutritional profile to be used in feeding programs for weaner rabbits. This will ensure sustainable animal production and add value to agricultural waste, which would otherwise constitute an environmental nuisance. Full article

Fungi, including filamentous organisms such as yeasts, play essential roles in various processes such as nutrient exchange in ecosystems, the cultivation of mushrooms, and solid-state fermentation (SSF). SSF involves microbial growth on solid substrates without free water, leading to the production of enzymes, bioactive compounds, and biofuels. This fermentation method offers advantages like lower production costs, reduced waste disposal issues, and the efficient utilization of agricultural residues and fruit and vegetable by-products. Filamentous fungi excel in SSF due to their enzyme secretion capacity and ability to produce valuable compounds. The process is influenced by biological, physico-chemical, and environmental factors, requiring careful optimization for optimal results. Fruit and vegetable by-products are increasingly recognized as valuable substrates for SSF, offering rich sources of bioactive compounds and high nutritional value. The optimization of SSF processes, compatibility with various substrates, and potential for producing diverse value-added products make SSF a promising method for sustainable resource utilization and enhanced product development. Future research should focus on improving process efficiency, expanding the substrate range, enhancing product quality and yield, and integrating SSF with other technologies for enhanced production capabilities. Full article

Three types of solid waste are produced during beer fermentation: spent grain, hot trub, and residual yeast. While the first is used as livestock feed, the seconds has not yet found any real reapplication in the field of circular economy. The aim of this work is to study and characterize these two brewing wastes, i.e., hot trub and residual yeast, to evaluate their potential reuse in the agricultural field. Samples from top-fermented and bottom-fermented beers were chemically investigated. Initially, the safety was assessed via multi-detection analysis of 57 mycotoxins, and all samples were deemed safe. Subsequently, the chemical and elemental composition was examined via ICP-MS and microanalysis, along with phenolic compounds and antioxidant activity via HPLC and spectrophotometric determinations, to achieve a thorough characterization of these waste samples. The C/N ratio of residual yeast from top-fermented beer and hot trub of the bottom-fermented one were near the optimal one (10:1). This research marks an initial step towards repurposing brewery waste materials as fertilizers. The subsequent steps will involve the formulation and field trials. Full article

This study explores the production of anhydrous ethanol from discarded fruits, aiming to determine optimal fermentation conditions and evaluate the feasibility of a green separation technology. Fermentation experiments were performed using juices from Psidium guajava (S1), Carica paapaya (S2), and mucilage residues of Coffea arabica (S3). All fermentations were carried out at a pH of 4.5 for 7 days in 1 L bioreactors. A full 2² factorial design was applied to evaluate the effects of two variables: yeast type (commercial Saccharomyces cerevisiae [CY] vs. native yeast [NY]) and temperature (21 °C vs. 30 °C). Higher ethanol concentrations were achieved with CY at 30 °C, yielding 6.79% ethanol for S3. A multi-criteria matrix prioritized coffee residues due to their high ethanol yield, biomass availability, and economic viability. The ethanol was dehydrated using a packed-bed bioadsorption system with crushed corn, which increased purity from 6.7% v/v to 98.9% v/v in two stages, while avoiding azeotropic limitations. Energy analysis revealed low specific consumption (3.68 MJ/kg), outperforming conventional distillation. The results of this study, obtained at operating temperatures of 30 °C and 21 °C, a pH of 4.5, and an operating time of 7 days in a 1L bioreactor, demonstrate ethanol concentrations of 6.79%, confirming the technical feasibility of using agricultural waste as a raw material and validating the efficiency of a bioadsorption-based dehydration system. These findings address the current gap in integrating green ethanol separation with low-cost agricultural residues and highlight a sustainable alternative for decentralized bioethanol production. Full article