Search Results (22)

The valorization of agricultural and food industry residues represents an important component of the circular bioeconomy, enabling the conversion of waste streams into value-added materials while mitigating environmental pollution. Spent coffee grounds (SCGs), a solid by-product generated during the extraction of coffee beans with hot water or steam, constitute an abundant lignocellulosic biomass residue. Due to their physicochemical properties, SCGs can be used as low-cost adsorbent materials for the treatment of metal-contaminated wastewater, offering a sustainable alternative to traditional synthetic resins. This review summarizes recent research on the application of SCGs for the removal of metal ions from aqueous systems. The adsorption performance of raw and modified SCGs, including materials obtained via carbonization and chemical functionalization, is comparatively evaluated. Furthermore, key operational parameters governing the adsorption process and the corresponding metal removal efficiencies are discussed. Full article

Coffee-derived materials from diverse botanical sources (beans, leaves, fruit and spent grounds) contain bioactive polyphenolic compounds, alkaloids, and diterpenes with potential dermatological applications. This review critically evaluates evidence quality across study designs. In vitro studies demonstrate antioxidant, anti-aging, anti-inflammatory, photoprotective, wound-healing, and antimicrobial activities. Animal models show photoprotection and wound-healing effects. These studies highlight the multifunctional dermatological value of coffee-derived materials as ingredients for cosmetic and therapeutic formulations aimed at combating skin aging, inflammation, and barrier dysfunction. Limited human trials (typically small sample sizes and short duration) report modest improvements in skin hydration, elasticity, barrier function, and reductions in erythema, transepidermal water loss, and ultraviolet-induced damage, though methodological limitations constrain interpretation. Observational epidemiological studies report inverse associations between coffee consumption and melanoma/basal cell carcinoma risk, but residual confounding by sun exposure, lifestyle factors, and genetic susceptibility precludes causal inference. Critical translational barriers include insufficient pharmacokinetic characterization, inadequate extract standardization across sources and processing methods, formulation challenges, bioavailability uncertainties, and limited independent validation. While preclinical evidence supports diverse biological activities and suggests multifunctional potential for cosmetic and therapeutic applications, current evidence remains insufficient to recommend coffee-derived products as a primary evidence-based dermatological intervention. Overall, large-scale, independent clinical trials with adequate duration and clinically meaningful endpoints are essential for translating laboratory findings into validated clinical applications. Full article

Most polymeric plastics used as food packaging are obtained from petroleum or made with non-biodegradable synthetic molecules, which slowly degrade and leach into the environment, resulting in the accumulation of microplastics along the trophic chains. To mitigate these impacts, biodegradable packaging derived from agro-industrial biomass residues has emerged as a promising alternative. In this study, bio-based methylcellulose films reinforced with cellulose nanocrystals (CNCs) extracted from low-quality coffee beans were developed and fully characterized. The extracted CNCs presented a needle-like morphology, with an average height of 7.27 nm and a length of 221.34 nm, with 65.75% crystallinity, were stable at pH 7–8, and presented thermogravimetric mass loss of 8.0%. Methylcellulose films containing 0.6% w/w of CNC were produced by casting and characterized in terms of thermal, mechanical, and optical properties. Notably, the incorporation of CNCs resulted in significantly more flexible and less rigid films, as evidenced by the higher elongation at break (57.90%) and lower Young’s modulus (0.0015 GPa) compared to neat methylcellulose film. The tensile strength was not affected (p > 0.05). Additionally, the MCNC 0.6% films effectively blocked UV light in the 200–300 nm range without compromising transparency. Altogether, these findings underscore the MCNC 0.6% film as a flexible, biodegradable packaging material suitable for food industry application. Full article

Agro-industrial residues rich in carbohydrates represent low-cost and sustainable feedstock for enzyme production. This study demonstrates that green Arabica coffee press cake, a mannan-rich coproduct of oil extraction, is an efficient carbon source for Aspergillus niger (CFAM 1234) cultivation and for inducing mannanase production. Furthermore, the enzymes obtained were tested for mannose recovery in the enzymatic hydrolysis of healthy and defective coffee beans to investigate their hydrolytic potential. Mannanase production was investigated using various carbon sources—including ground coffee beans; coffee press cake; different particle sizes of coffee press cake; aqueous coffee cake extract (prepared at 30 g·L⁻¹ under constant stirring (300 rpm) at 80 °C for 2 h, followed by filtration.); and a commercial galactomannan, locust bean gum (LBG). CNHSO analysis was performed in the best carbon source (coffee press cake) and LBG. Statistical optimization (Plackett–Burman and Central Composite Rotatable Design) simplified the culture medium composition to coffee press cake (48.78 g·L⁻¹), yeast extract (4 g·L⁻¹), and potassium phosphate (0.25 g·L⁻¹, pH 5.5) and increased mannanases productivity to 22.4 ± 0.6 U·mL⁻¹ within only 3 days (a 42.9% improvement compared to non-optimized conditions, which were 30 g·L⁻¹, carbon source, 4 g·L⁻¹ yeast extract, 1 g·L⁻¹ Al₂O₃, 0.5 g·L⁻¹ potassium phosphate buffer (pH 5.5), 0.5 g·L⁻¹ of MgSO₄·7H₂O, and 0.05 g·L⁻¹ of CaCl₂·2H₂O, which resulted in a maximum of ~20 U·mL⁻¹ in 7 days). The crude extract also exhibited β-mannosidase activity (1.39 ± 0.06 U·mL⁻¹). When applied to the hydrolysis of untreated healthy and defective coffee beans, the enzyme preparation enabled ~25% mannose recovery (considering the value obtained through acid hydrolysis as 100%), highlighting its potential as a mannose resource. The results demonstrate that coproducts from the coffee production chain can be used as an efficient carbon source (coffee cake) for mannanase production, as well as sugar recovery (defective coffee beans), offering an integrated strategy to strengthen the circular bioeconomy and generate carbohydrates with potential industrial and nutritional applications. 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

Particleboards were developed by replacing a part of wood with various biomass residues, including coffee bean husks, spent coffee grounds, thistle, Sideritis and dead leaves of Posidonia oceanica. These materials were analysed to determine their physicochemical properties like the moisture content, pH, and buffer capacity, using standard laboratory techniques, while thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were also used for their further characterisation. The results revealed that all biomasses contained cellulose, hemicellulose, and lignin in varying proportions, along with differing degrees of crystallinity. To produce particleboards, the biomasses were bonded using two types of adhesives: (a) conventional urea-formaldehyde resin (UF) and (b) polymeric 4,4′-methylene diphenyl isocyanate (pMDI). Laboratory-scale, single-layer particleboards were manufactured simulating industrial production practices. These panels were evaluated for their mechanical and physical properties according to European standards. The findings showed a general reduction in mechanical performance when compared to conventional wood-based panels. However, panels made with coffee grounds and Posidonia showed improved resistance to thickness swelling after 24 h in water at 20 °C. Additionally, all experimental panels exhibited lower formaldehyde content than wood-based reference panels. This study demonstrated the feasibility of upcycling biomass residues as a sustainable alternative to virgin wood in the production of particleboard, providing a resource-efficient solution for specific interior applications within a circular economy framework. 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

Improper waste disposal is one of the leading causes of environmental pollution, impacting soil, water, and air quality. In coffee plantations, each kilogram of beans produced generates an equal amount of husk, emphasizing the urgent need for sustainable practices to process this residual biomass into valued products. This study aimed to evaluate the potential of coffee husks for pellet production. Three coffee husk types were selected with distinct chemical compositions and granulometries: I (>5.3 mm), II (>2.6 mm and <5.3 mm), and III (<1.77 mm). The biomass was characterized for elemental, structural, and proximate composition. Pellets were produced with two knife heights (15 and 20 mm) and assessed for moisture content, density, length, and mechanical resistance, which were compared with the EN 14691-6 standard (DIN, 2012). Pelletizer productivity was also evaluated. Pellets from biomass III had an ash content of 12.09%, exceeding the <10% requirement. Other treatments met the ash content standard, category B. Pellets from biomass I (17.55%) and II (18.1%) at 15 mm length did not meet the <15% moisture content standard. The remaining pellets met category B standards. Only pellets from origin III (1.62%) met the nitrogen content requirement for international trade (<2%). Pelletizer productivity was higher with smaller granulometry biomass. Coffee husk has demonstrated its potential for pellet production, highlighting the valorization and use of this waste for clean energy generation, contributing to greenhouse gas emissions mitigation, and strengthening circular economy. Full article

Soxhlet extraction is a method recommended by the Association of Official Analytical Chemists (AOAC) to determine the lipid content in plant samples. Generally, n-hexane (toxicity grade 5) is used as the solvent (≈300 mL; ≈30 g sample) at boiling temperatures (69 °C) for long times (≤16 h) under a chilled water reflux (≈90 L/h), proportionally aggravated by the number of repetitions and samples determined. In this sense, the technique is neither safe nor sustainable for the analyst or the environment. This article presents the development of an alternative and more sustainable procedure for determining the lipid content in raw Arabica coffee beans. A 3³ full factorial design was used to perform direct hot solid–liquid extractions in 4 mL vials, varying the ground grains and solvent ratios, temperatures, and times. An optimal condition resulted in an extractive yield statistically equivalent to Soxhlet, without variation in the composition of the oil fatty acids determined by GC-MS after hole oil transesterification. This procedure was presented as a sustainable alternative to Soxhlet extraction because it does not require water for cooling and needs a smaller volume of solvent (2 mL) and sample mass (0.2 g); it also has a smaller generated residue, as well as requiring a shorter time (1.5 h) and less energy expenditure for extraction. Full article

The coffee industry, while processing coffee beans, generates residues like husk, pulp, and silverskin, which have been considered a promising source of bioactive metabolites. Recovering these metabolites offers a sustainable strategy to obtain natural food additives. Based on the above, this study aimed to determine the effect of the aqueous extract obtained from maceration and fungal fermented coffee silverskin (CSS) on ground pork meat’s oxidative and microbiological stability. Treatments used to recover bioactive compounds from CSS were the following: maceration extraction (ME) using 0, 1.5, and 3.0% of CSS (ME–0%, ME–1.5%, and ME–3%); fungal submerged fermentation extraction (FE) using 0, 1.5, and 3.0% of CSS (FE–0%, FE–1.5%, and FE–3%) and Pleurotus pulmonarius mycelium. Concerning metabolite content and bioactivity, results showed a decrease in the carbohydrate content of the ME and FE-obtained, as well as an increase in the phenol, flavonoid, and caffeoylquinic acid content. Also, an increase in radical cation scavenging activity, reducing power values and antibacterial activity of the extracts obtained with FE, was observed. Regarding pork meat homogenate treated with ME and FE extracts and subjected to oxidation with potassium ferrocyanide, results demonstrated that inclusion of FE-obtained extract led to decreased pH, lipid oxidation, metmyoglobin, and color changes (L*, a*, b*, C*, and h*), and microbial growth. These results demonstrate that CSS aqueous extract obtained with FE can be considered a potential additive for the meat industry with antioxidant and antibacterial activity. Nevertheless, further research is necessary to assess the sensory impact, biochemical mechanism, food safety, sustainability, and industrial feasibility of these extracts for broader applications. Full article

Dichloromethane (DCM) is extensively used around the globe in various applications, such as in closed industrial installations for food processing or pharmaceutical extractions (vitamins, antibiotics, etc.). In the coffee sector, it is used as an extraction agent for the decaffeination process of green coffee beans. Due to its low boiling point, ranging at approx. 40 °C, DCM can be easily removed subsequent to caffeine extraction by applying state-of-the-art solvent stripping processes. The intention of this study is to assess how much DCM, if any, is present in decaffeinated coffee packages as sold to the consumer, as well as how much of the extraction solvent residue is transferred into the finally prepared, consumable coffee beverage. This study sets out to highlight DCM contents of decaf coffees, directly taken from six EU countries’ supermarket shelves. In addition, DCM mass transfer rates from roasted coffee matrices into the corresponding, variously prepared beverages (drip percolated coffee, French press) are determined. All analyses were performed applying a Headspace-GC-MS technique. All presented data demonstrate that DCM residues in the 34 coffee samples analysed have contents well below the DCM maximum residue limits for roasted coffee both in the European Union (2 mg/kg) and the USA (10 mg/kg), with an average of 0.127 mg/kg, median value of 0.059 mg/kg and P95 of 0.444 mg/kg. Furthermore, this study shows that DCM mass transfer rates from the coffee matrices into the corresponding beverages have, for drip coffee, an average of 24.7% and median of 26.8%, and for French press, an average mass transfer of 41.9% and median of 43.1%. Full article

Agricultural residues are a source of energy derived through various conversion processes. They are gaining attention as a solution to limited energy access in developing countries in which a majority of the population depends on agriculture for a living at a time when global population growth is outpacing the depreciation of conventional energy sources. This study characterized residues generated along the main agri-food value chains in Uganda for gasification by reviewing relevant literature and through field measurements and laboratory experiments. Maize, beans, cassava, banana, coffee, and sugarcane are the most important value chains, occupying 5.73 million hectares, and accounting for 40% of the country’s total area under cultivation. In terms of biomass residues, banana, maize, and sugarcane are the most feasible options, producing 4.18, 2.2, and 0.6 metric tons of biomass waste per ton, respectively. The bulk densities vary from 65.5 to 160 kg/m³, moisture content from 6.67 to 22.5%, and heating values from 12.6 to 16.74 MJ/kg for all residues. In terms of principal elements, oxygen has the highest proportion of 38.76–57.25% followed by carbon, 33.46–47.9%, and hydrogen 6%. The lignocellulosic composition is 23.46–41.38% hemicellulose, 9.9–55% cellulose, and 5.77–35% lignin. The three value chains have the potential to generate 172.2 PJ annually, which is enough to offset 50% of the cooking energy demands for Uganda. The main disadvantage of this is the low bulk density, which raises production costs and reduces conversion efficiency. Bulk density can be improved by densification through the compaction of residues. Given their composition and current utilization, maize stover, banana leaves, banana pseudo stems, and sugarcane tops are promising gasification feedstocks. Full article

Processing the coffee cherry into roasted beans generates a large amount of by-products, which can negatively impact the environment. The aim of this study was to analyze the bioactive potential and chemical composition of different coffee by-products (pulp, husk, parchment, silverskin, defective beans, and green coffee sieving residue) having in mind their bioactive potential for health and well-being. The coffee by-products showed a distinct nutritional composition. The content of ash, protein, fat, and total dietary fiber was significantly higher (p < 0.05) in coffee pulp (10.72% dw), silverskin (16.31% dw), defective beans (8.47% dw), and parchment (94.19% dw), respectively. Defective beans and the sieve residue exhibited a higher content of total phenolics (6.54 and 5.11 g chlorogenic acid eq./100 g dw, respectively) as well as higher DPPH^• scavenging activity (3.11 and 2.85 g Trolox eq./100 g, respectively) and ferric-reducing antioxidant power (17.68 and 17.56 g ferrous sulfate eq./100 g dw, respectively). All the coffee by-products considered in this study are sources of caffeine and chlorogenic acids, in particular 5-caffeoylquinic acid (5.36–3787.58 mg/100 g dw, for parchment and defective beans, respectively). Thus, they can be recycled as functional ingredients for food, cosmetic and/or pharmaceutical industries, contributing to the social, economic, and environmental sustainability of the coffee industry. Full article

A growing research interest currently exists in the use of paper as a building material. This work aims to present the results of a measurement campaign developed on innovative waste paper-based building components. The research was carried out in Southern Italy and used some local by-product aggregates. Three different mixture designs were developed in the laboratory by adding three kinds of biomass to a pulp paper blend: fava bean residues (FB), sawdust powder (SP) and coffee grains (CG) extracted from exhausted chaffs. A physical characterization was carried out measuring the bulk density and bulk porosity. Scanning Electron Microscopy (SEM) analysis of the single aggregates was followed by a microstructure analysis of the final components. Bulk density evaluation showed a range between 200 and 348 kg·m⁻³. Furthermore, thermal performances were measured; the thermal conductivity of the experimented samples ranged from 0.071 to 0.093 W·m⁻¹·K⁻¹, thus it is possible to classify the tested materials as thermal insulators. Moreover, the acoustic properties were evaluated and tested. The normal incidence sound absorption coefficient was measured by the impedance tube on cylindrical specimens. In general, a different behavior was observed between the upper and lower base of each specimen due to the manufacturing process and the shrinkage caused by the different interactions occurring between the aggregates and the pulp paper waste; for example, the presence of sawdust reduced shrinkage in the final specimens, with consequent smaller physical variations among the two faces. The correlation existing between the manufacturing process and the microstructural properties was also investigated by the estimation of the non-acoustical parameters using the inverse method and taking into account the JCA (Johnson, Champoux and Allard) model as a reference. Full article

To take advantage of the residues generated in the production of products from green coffee and due to the special interest in the compounds contained in the bean, a by-product obtained after the extraction of the oil was studied. The physical characterization of the green-coffee-bean by-product was carried out. Subsequently, the extraction of compound 5-CQA was carried out via leaching using central composition design 2⁴ and evaluating factors such as temperature, time, solid/solvent ratio, and ethanol percentage, and its yield was quantified using HPLC. In addition, the response-surface methodology was used to maximize the efficiency of 5-CQA extraction and to perform the kinetic study. Yields of 59 ± 2 mg of 5-CQA/g from the by-product were obtained, and by selecting the best leaching conditions, the kinetic study was performed at 45, 60, and 75 °C, increasing the yield to a total of 61.8 ± 3 mg of 5-CQA/g. By applying the kinetic model of mass transfer, a fit of R² > 0.97 was obtained, with $K_{L}a$ values between 0.266 and 0.320 min⁻¹. This study showed an approach to optimize the 5-CQA extraction conditions, resulting in a simple, fast, reproducible, accurate, and low-cost method. Full article