Search Results (96)

Coffee oil, an increasingly recognized yet underutilized byproduct of spent coffee grounds, has attracted attention due to its diverse lipid composition and minor components. This study systematically investigated the lipid characteristics of coffee oils extracted from both Arabica and Robusta spent coffee grounds subjected to varying roasting degrees. Comprehensive analyses were conducted, mainly regarding oil yield, acid and peroxide values, fatty acid profiles, sn-2 positional fatty acid distribution, triacylglycerol composition, tocopherol content and total Folin-reactive compounds, as well as squalene and sterol profiles. The selected Arabica samples generally showed higher oil yields than Robusta samples, with oil contents ranging from 12.13% to 15.14% and 10.10% to 13.01%, respectively. Arabica coffee oils showed relatively high total tocopherol levels, ranging from 930.35 to 1495.37 mg/kg, whereas Robusta coffee oils ranged from 637.69 to 867.21 mg/kg. Total Folin-reactive compounds varied among samples and should be interpreted as composition-related indicators rather than direct evidence of antioxidant function. In contrast, Robusta coffee oils contained much higher levels of squalene and total sterols, ranging from 97.00 to 170.37 mg/100 g and 787.29 to 1007.92 mg/100 g, respectively. Chemometric analyses showed distinct grouping patterns among the selected coffee oil samples. In the present sample set, the overall lipid profiles were more closely associated with the Arabica and Robusta sample groups than with the assigned roasting levels. These results provide compositional information for the potential use of Arabica coffee oil as a tocopherol- and Folin-reactive compound-rich lipid ingredient. Robusta coffee oil may be further evaluated for applications requiring higher levels of squalene, phytosterols, and relatively saturated lipid structures. This study provides novel insights into the compositional complexity of coffee oil and supports its targeted valorization across various industries. Full article

This review aims to comprehensively examine spent coffee grounds (SCGs) as a sustainable source of antioxidant and immunomodulatory bioactives, with a specific focus on their capacity to modulate membrane-level signaling through ion channels and G-protein-coupled receptors (GPCRs) in the context of lifestyle-related chronic diseases. SCGs, the major solid by-product of coffee brewing, represent an underutilized yet highly abundant source of bioactive compounds, including chlorogenic acids, phenolic acids, melanoidins, diterpenes, and residual alkaloids. Lifestyle-related chronic diseases, including type 2 diabetes, obesity, cardiovascular disease, and chronic inflammatory disorders, are increasingly recognized as immunometabolic conditions driven by persistent low-grade inflammation, redox imbalance, and dysregulated membrane signaling. This review synthesizes current evidence demonstrating that bioactives contained in SCG extracts exert antioxidant and immunomodulatory effects that extend beyond radical scavenging. Crucially, these compounds also act as modulators of membrane-level signaling, representing a mechanistic perspective that has not been previously integrated for SCGs in the context of chronic disease. The different extraction methodologies and the obtained results are evaluated with the aim to identify the most effective experimental approach and extraction conditions. The paper also discusses how SCG compounds regulate redox-sensitive ion channels (including calcium channels, TRP channels, and potassium channels), and key GPCR pathways (such as GPR120, GPR43, and adenosine receptors), thereby influencing immune cell activation, cytokine production, insulin signaling, and metabolic inflammation. Particular attention is given to the role of microbial fermentation and enzymatic processing in enhancing SCG bioavailability, generating postbiotic metabolites that further engage GPCR–ion channel crosstalk. By integrating extraction approaches, antioxidant chemistry, immunology, membrane signaling, and nutritional metabolism, this review positions SCG as a sustainable functional ingredient capable of restoring immune tolerance and metabolic homeostasis. These insights support the valorization of SCGs within the circular economy framework and highlight their potential application in next-generation immunonutrition strategies for chronic disease prevention and management. Full article

The recovery of antioxidant compounds from agri-food by-products represents a sustainable strategy for active packaging production. However, the compatibility between natural extracts and film-forming techniques plays a key role in determining film formation and properties. In this work, antioxidant extracts obtained from spent coffee grounds and tomato waste were incorporated into zein-based films produced using two different techniques. The objective was to investigate how extract type and processing technique influence film morphology, wettability, thickness, and mechanical properties. The results demonstrated a strong processing-dependent compatibility between extract composition and production techniques. Spent coffee ground extract was successfully incorporated into compact cast films, while tomato waste extract did not allow the formation of homogeneous cast films and required electrospinning to obtain uniform fibrous structures. The incorporation of spent coffee ground extract significantly increased surface wettability and film stiffness, with Young’s modulus reaching 695 MPa. In contrast, electrospun films containing tomato waste extract exhibited lower tensile strength due to their porous fibrous structure, although uniform fibers were obtained. These findings demonstrate that extract chemistry critically affects the suitability of the processing technique and provide useful guidelines for the design of sustainable zein-based active packaging systems derived from agri-food waste valorization. Full article

Coffee is among the most widely consumed beverages globally being cultivated in nearly 80 countries. Its processing generates large quantities of by-products, including mucilage, pulp/husks, silverskin, parchment, and spent coffee grounds. Although traditionally treated as waste, these residues are increasingly recognized as valuable resources rich in bioactive compounds exhibiting antioxidant, antimicrobial, and health-promoting properties. This review explores the antimicrobial potential of coffee by-products, with particular emphasis on their chemical composition and mechanisms of action. Compounds such as caffeine, chlorogenic acids, polyphenols, and melanoidins have demonstrated inhibitory effects against a broad spectrum of bacteria, including both Gram-positive and Gram-negative bacteria. Many of these compounds, which originate from plant’s defensive system or result from Maillard reactions, are known to disrupt microbial membranes, inhibit DNA repair, and interfere with pathogen metabolism. However, the available literature on their antimicrobial effectiveness remains limited. In the context of the rising worldwide concern over antimicrobial resistance, coffee by-products represent a sustainable and promising source of novel antimicrobial agents. Their valorization may support advances in food preservation, pharmaceutical innovation, and waste management practices, contributing to the implementation of a circular economy framework in the coffee industry while promoting environmental, economic, and social sustainability. Full article

Spent coffee grounds (SCGs), a major by-product of coffee consumption, remain an underused source of chlorogenic acid (CGA) and other phenolic constituents. This study investigated an ultrasound-assisted extraction strategy using deep eutectic solvents (DESs) to improve the recovery and phenolic-acid enrichment of SCGs. Among the tested DES formulations, the betaine–acetic acid system gave the best CGA extraction performance and was therefore used for further optimization by response surface methodology. The optimized process, conducted at a liquid-to-solid ratio of 28 mL/g, 75 °C, and 50 min, produced a CGA yield of 15.18 mg CGA/g dried SCG powder, markedly exceeding that achieved with 70% ethanol under comparable conditions. Structural and chemical characterizations helped explain this improvement. Scanning electron microscopy revealed that the DES-based process caused more evident disruption of the SCG matrix, which favored solvent penetration and mass transfer. Fourier-transform infrared spectroscopy confirmed the formation of a hydrogen-bonding network between betaine and acetic acid. Ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry further revealed that the betaine–acetic acid extract was mainly composed of CGA and hydroxycinnamic acid derivatives. The purified extract also displayed strong in vitro antioxidant capacity. Overall, the betaine–acetic acid DES combined with ultrasound provides an effective green approach for recovering CGA-rich phenolic extracts from SCGs. Full article

Food waste fashion—garments produced from agricultural and food industry by-products, such as fruit peels, coffee grounds, and grape marc—represents a radical yet understudied innovation within the circular economy. This study proposes the Fashion Innovation Adoption Model, a novel framework that organizes consumer adoption of fashion innovations across three hierarchical levels: a distal level comprising sociodemographic characteristics, an intermediate cognitive–evaluative level comprising consumer decision-making styles and functional product attribute evaluations, and a proximal psychosocial level comprising attitudes, static and dynamic social norms, and past fashion purchasing behavior. The model is applied for the first time to food waste fashion as a paradigmatic case of radical circular innovation in the textile sector. Hypotheses were tested via structural equation modeling on a sample of 396 Italian consumers. Purchase intention was directly predicted by attitudes, static and dynamic norms, and general fashion purchasing, whereas sustainable fashion purchasing showed no effect. Among product attributes, only sustainability information influenced both attitudes and intentions. Perfectionism and hedonism were positively associated with intention through sustainability information, while impulsivity and habit were negatively associated with intention. Sociodemographics influenced intention only indirectly, via cognitive and normative mechanisms. These findings reveal complex pathways linking psychological profiles and perceived product attributes to circular fashion adoption, with implications for communication strategies emphasizing sustainability information and targeting heterogeneous consumer motivations. Full article

Spent coffee grounds (SCGs) are abundant byproducts generated during coffee processing that are unsuitable for storage and subsequent value-added utilization owing to their high moisture content and water activity (a_w). This study investigated the effects of different infrared power levels (800, 900, and 1000 W) on drying kinetics, product quality, and energy efficiency to determine the preferred drying parameters for SCGs. The initial moisture content and a_w of SCGs were 63.56% (wet basis) and 0.95, respectively. To enhance mechanistic understanding, the drying data were fitted to four mathematical models, with the Midilli and Page models providing the best fit (R² > 0.99). Drying experiments were conducted under a sample thickness of 0.7 cm and a loading of 500 g, with a final moisture content of <10% as the drying endpoint. The results showed that as infrared power increased, drying time decreased from 30 to 24 min and the drying rate significantly increased from 10.32 to 12.77 g H₂O/min (p < 0.05). The drying process was mainly characterized by a falling-rate period, with the effective moisture diffusivity ranging from 0.97 to 1.15 × 10⁻⁸ m²/s and increasing with rising power, indicating that internal moisture diffusion was the dominant drying mechanism. The final a_w of each treatment group was ≤0.60, indicating good storage stability. Color analysis showed that the color differences in treatments at higher power levels (900 W and 1000 W) were significantly lower than those at lower ones (p < 0.05). While the specific energy consumption (SEC) showed a marginal decrease from 5.80 to 5.68 kWh/kg at higher power, a comprehensive evaluation of drying efficiency, quality characteristics, and energy consumption indicated that 1000 W was the preferred infrared drying power under the conditions employed in this study. These results confirm that infrared drying is an efficient stabilization method with strong potential for rapid stabilization of food processing byproducts. Full article

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

Spent coffee grounds (SCGs) are one of the most abundant agro-industrial by-products worldwide, with 650 kg generated per ton of green coffee processed, corresponding to an estimated global production of 6.7 million tons in 2022/2023. Improper disposal of SCG raises environmental concerns, while their reuse offers opportunities for sustainable resource management and circular economy strategies. This review examines SCG valorization by addressing their chemical composition, functional properties, and key applications in sectors such as food, agriculture, environmental remediation, bioenergy, and selected industrial fields, including pharmaceuticals, cosmetics, construction materials, and functional devices. In this context, it discusses technological approaches, performance outcomes, and implementation considerations, emphasizing the multifunctional potential of SCGs as a renewable feedstock capable of reducing waste, improving resource efficiency, and generating economic value. By consolidating the current state of knowledge and exploring diverse valorization pathways, this work frames SCG utilization within a circular bioeconomy framework and highlights how innovative applications can transform this widely available waste into sustainable and economically valuable products. Full article

Spent coffee grounds (SCG) are the main by-product generated by the coffee industry, with an estimated annual production of approximately 7 million tons. Although commonly treated as waste, SCG constitute a valuable source of phenolic compounds, particularly chlorogenic acid, which has been associated with antimicrobial, antioxidant, antimutagenic, anti-inflammatory, and cardioprotective properties. These bioactive compounds are of interest as functional ingredients for food, cosmetic, and pharmaceutical applications. However, their recovery by conventional extraction methods often depends on volatile, flammable, or toxic organic solvents. In this context, hydrophobic eutectic solvents (HES) have emerged as a greener and more sustainable alternative. In the present study, phenolic compounds were extracted from SCG using HES combined with microwave-assisted extraction (MAE). Sixteen terpene-based HES formulated with fatty acids and fatty alcohols were evaluated. Among them, camphor:dodecanoic acid and borneol:dodecanoic acid gave the highest total phenolic contents. Process optimization showed that the borneol:dodecanoic acid system, under 12% water content, a 1:10 solid-to-liquid ratio, 57 °C, and 120 min, reached 80.94 ± 4.44 mg GAE g⁻¹ by MAE. HPLC analysis revealed chlorogenic, caffeic, and ferulic acids as the main phenolic compounds, while the extracts also displayed high antioxidant activity. Overall, these findings demonstrate that HES-MAE is a promising and sustainable strategy for the recovery of value-added phenolics from SCG. Full article

The sustainable processing of coffee requires not only improving the efficiency of conventional operations but also advancing the recovery and valorization of bioactive compounds across the coffee value chain. In this context, emerging technologies offer eco-efficient alternatives to conventional extraction methods. This review summarizes recent advances in ultrasound-assisted extraction (UAE), high-pressure extraction (HPE), cold atmospheric plasma (CAP), and microwave-assisted extraction (MAE) applied to coffee beans and major coffee side streams, including pulp, husk, parchment, silverskin, and spent coffee grounds. The physicochemical principles of each technology, the main operating parameters, and their influence on extraction yield, phenolic composition, antioxidant capacity, and heat-sensitive compound preservation are discussed. Furthermore, potential synergies between combined techniques (UAE-MAE or HPE-UAE) and trends toward industrial scaling and integral valorization within a circular economy framework are highlighted. Overall, the evidence indicates that emerging technologies can intensify coffee extraction processes, increase phenolic recovery (often achieving up to two-fold improvements in total phenolic content compared to conventional techniques), and significantly reduce processing times (commonly reaching 2.5–15 min), supporting more sustainable and industrially relevant value chains. Full article

Spent coffee grounds (SCGs) represent a globally abundant agro-industrial byproduct with underexploited potential in circular bioeconomy applications. This study investigates the extraction, characterization and functional integration of SCG protein concentrate into aquafeed formulations for common carp (Cyprinus carpio). Protein was recovered through alkaline extraction followed by isoelectric precipitation, yielding a concentrate incorporated at 5% into a mixed plant and fishmeal diet produced by cold pelletizing. Compositional analysis performed by FT-NIR showed 33.6% crude protein, 7.24% lipids and 7.85% fiber, while ICP-OES confirmed substantial levels of essential minerals including Ca, P, K and Mg (15.3, 8.4, 10.4 and 2.3 g/kg). SCGs contributed bioactive compounds, with total polyphenols reaching 1.521 ± 0.065 mg GAE/g DM and an antioxidant capacity of 3.35 ± 0.03 mg TE/g DM. Pellets exhibited high water stability (91.8% retention after 30 min), and a short-term feeding test demonstrated strong acceptance by juvenile carp (91.2 ± 2.1%) consumption. Residual caffeine levels remained low (3.5 mg per g dry weight) and within safe exposure margins for freshwater fish. The results demonstrate the technical feasibility of incorporating SCG protein concentrate into compound aquafeeds without compromising pellet integrity or short-term palatability, while increasing feed-level antioxidant potential. However, the findings represent a proof-of-concept evaluation. Further research involving longer-term feeding trials, digestibility assessment, and amino acid profiling of complete diets is required to validate nutritional performance and optimize inclusion strategies for sustainable aquaculture. Full article

Coffee is the second most widely traded commodity worldwide. This makes the management and valorization of waste generated during its production and brewing of considerable importance. Spent coffee grounds (SCG), the residue remaining after coffee brewing, account for approximately seven million tons of waste produced annually. Due to their nutrient-rich composition, SCG have significant potential for reuse in various sectors. This review briefly examines SCG’s applications as nutritional additives and flavoring agents in the food industry; as sorbent materials for removing chemical contaminants from water and air; as UV-protective and hydrating ingredients in cosmetics; and as a source of bioactive compounds with health-promoting properties in the pharmaceutical industry. Full article

The revalorization of food processing by-products represents a critical strategy for enhancing resource efficiency and advancing circularity within the food system. This review examines the potential of three major plant-based agro-industrial by-products—fruit and vegetable residues, brewer’s spent grain, and spent coffee grounds—as sources of high-value functional ingredients. These by-products contain bioactive compounds, including dietary fibers, polyphenols, proteins, peptides, oils, and antioxidants, that can be recovered using emerging green extraction and bioprocessing technologies. Conventional extraction methods are progressively being replaced or hybridized with enzyme-assisted, ultrasound-assisted, microwave-assisted, and deep eutectic solvent techniques to improve yield, reduce solvent consumption, and preserve bioactivity. The recovered compounds have demonstrated promising applications as gelling agents (pectin), natural colorants and antioxidants, protein-enriched flours, prebiotic fibers, and bioactive extracts for functional food and nutraceutical formulations. However, challenges persist in standardizing feedstock composition, scaling continuous extraction processes, ensuring safety and regulatory compliance, and generating robust techno-economic and life-cycle assessments to validate sustainability claims. This review synthesizes biochemical composition data, processing pathways, food applications, and regulatory considerations, and identifies research priorities for developing integrated, scalable biorefinery models that valorize food by-products into market-ready functional ingredients. Full article

This study reports the effective reuse of coffee residues from roasting and brewing processes using microwave-assisted extraction (MAE) of bioactive compounds. Principal Component Analysis (PCA) showed a significant impact (p < 0.001) on phenolic acid and alkaloid amounts among coffee (green and roasted) and its by-products (silver skin and spent grounds). Furthermore, a linear mixed-effects model identified that, apart from sample type, extraction temperature (50 and 70 °C) and ethanol volume fractions (50 and 70%, v/v) considerably influenced the quantities of bioactive compounds. The best conditions were achieved using 70% (v/v) ethanol at 70 °C. In addition to caffeine and chlorogenic acid, which were found in the highest amounts, the coffee and by-product samples contained high levels of total fibre (20.7–27.8%) and total fat (1.5–12.4%). Fatty acid analysis showed a dominance of oleic acid (7.55–12.7%), palmitic acid (19.3–40.3%), and linoleic acid (15.6–41.8%), with their saturated and unsaturated nature confirmed by Fourier Transform Infrared (FTIR) Spectroscopy. The reported data highlight the potential of coffee by-products as high-value sources for bioactive compound recovery. Full article