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Spent coffee grounds (SCGs), a by-product of coffee brewing, have high application potential. However, their high moisture content complicates conventional conversion without energy-intensive drying. This study explores a new route to convert SCGs to high-carbon bioproducts, such as hydrochar and bio-oil, through hydrothermal processing. The effect of the processing variables, i.e., temperature, residence time, and the application of the binary solvent as a reaction medium, on the distribution of the resultant bioproducts was investigated. The quality of the fabricated bioproducts was analyzed by means of instrumental techniques such as EA, ATR-FTIR, GC-MS, and GC-TCD-FID. Two dominant fractions were liquid bio-oil and solid hydrochar. The highest char yield (39 wt.%) was observed under milder conditions (low T and short residence times), while more severe conditions led to an increase in bio-oil formation, which reached a maximum of 46 wt.%. The resulting bio-oils were of similar quality, presenting high carbon content (71–74 wt.%) and energetic values (approximately 35 MJ/kg). Also, hydrochars showed a noticeable energy densification compared to raw materials, where the C content and HHV reached up to 73.8 wt.% and 30 MJ/kg, respectively. The addition of co-solvent to water improves the bio-oil yield as a result of the enhanced stabilization of reactive intermediates. [ABSTRACT FROM AUTHOR]

The waste materials generated from the processing of coffee cherries are still rich in several bioactive compounds. Several studies highlight coffee by-products as a valuable source for diverse applications, such as biofuels, biopolymers, biocomposites, and natural antioxidants in food, pharmaceuticals, and cosmetics. The development of prospective strategies for the valorization of coffee wastes is a goal of a sustainable and circular bioeconomy, increasing the added value of these wastes and reducing environmental pollution. This brief overview describes the recently proposed procedures for the extraction and recovery of functional ingredients from the diversity of coffee by-products. The comparison between conventional and alternative extraction methods enables one to choose the most suitable techniques for valorizing a given coffee by-product. [ABSTRACT FROM AUTHOR]

Over the last two decades, the use of bioreactors filled with aged refuse extracted from closed areas of landfills has proven to be a viable alternative for the treatment of different types of wastewater. This study presents the results obtained during the evaluation of aged refuse used as filling material for a downflow bioreactor during the removal of the organic load present in wastewater generated in the wet processing of coffee. The tests were carried out over a period of 120 days, with 15 days to start up and stabilize the bioreactor and 105 days to perform treatability tests. The aged refuse, once extracted, was dried and sifted to a particle size of less than 50 mm. The bioreactor used had a cylindrical geometry (Ø = 0.20 m, and h = 3.40 m), and it was fed with hydraulic loads of 50, 100, and 150 L m−3 d−1. The analysis of the data obtained shows that the system studied achieves the removal of 98.3% of the initial organic load when fed with 150 L m−3 d−1. This showcases recycling aged refuse as a technically viable alternative to treat the wastewater generated during coffee processing. Also, the evaluated system has the advantage of needing a short period of time to achieve its stabilization, which turns out to be of great value, especially in its possible use in the treatment of residual water generated in the harvest of agricultural products where the period of harvest is very short. [ABSTRACT FROM AUTHOR]

Coffee silverskin (CS) is a by-product of the coffee roasting process that is known for its potential as a fiber source with antioxidant properties. Therefore, this study aimed to provide an overview of the latest research on CS as a potential ingredient for functional foods and to evaluate the effect of adding different amounts of CS on the functional and sensory attributes of chocolate cakes. The addition of CS increased the total dietary fiber content, antioxidant capacity and the contents of extractable and non-extractable phenolics in the cakes. The evaluated sensory attributes were color, smell, taste, texture and overall impression, and they were evaluated according to a 9-point hedonic scale. Internal preference maps were obtained based on the results from acceptance and "intention to buy" tests. In general, the cakes with lower coffee silverskin content (2.6% and 3.6%) had a similar level of acceptance and the cake with 4.6% coffee silverskin content was the least accepted. The most important attributes were taste and overall impression, corresponding to "like slightly" and "like moderately" for the cakes that had better acceptance. Nonetheless, even with the lowest amount of added CS (2.6%), the produced cakes could be regarded as antioxidant fiber sources (with fiber content above 3 g/100 g), thus confirming the potential of CS as a functional food additive. [ABSTRACT FROM AUTHOR]

The washed process is one of the traditional post-harvest processes of coffee beans, which include selective harvesting, flotation, pulping, submerged fermentation underwater, washing, and drying operations. During the washed processing, fermentation underwater can remove coffee mucilage and change metabolites by microorganisms. Therefore, coffee fermentation is a key factor influencing coffee's flavor. To compare the influence of fermentation duration in an open environment of Coffea arabica in 48 h during the washed processing on the coffee's flavor, the sensory characteristics of the coffee at different fermentation durations were evaluated using the Specialty Coffee Association of America (SCAA) cupping protocol. Moreover, ultra performance liquid chromatography–triple quadrupole mass spectrometry (UHPLC–MS/MS) and gas chromatography–mass spectrometry (GC–MS) were combined to analyze and compare the chemical compounds of coffee samples from fermentation durations of 24 h (W24) and 36 h (W36) during the washed processing method. The results showed that W36 had the highest total cupping score with 77.25 in all different fermentation duration coffee samples, and 2567 non-volatile compounds (nVCs) and 176 volatile compounds (VCs) were detected in W36 and W24 during the washed processing method. Furthermore, 43 differentially changed non-volatile compounds (DCnVCs) and 22 differentially changed volatile compounds (DCVCs) were detected in W36 vs. W24. Therefore, suitable fermentation duration in an open environment is beneficial to coffee flavor, judging by chemical compound changes. For the washed primary processing of C. arabica from Yunnan, China, 36 h fermentation was the suitable fermentation duration in an open environment, which presented potential value as the reference for washed coffee processing in the food industry. [ABSTRACT FROM AUTHOR]

The coffee pulp, a significant by-product of coffee processing, is often discarded but has potential for recycling and high-value uses. This study aimed to investigate the chemical composition of two coffee pulp ingredients, a flour (CPF) and an aqueous extract (CPE), and conducted acute and sub-chronic toxicity assays to determine their safety. The proximate composition revealed the high fiber content of both ingredients; the CPF mainly contained insoluble fiber, while CPE consisted exclusively of soluble pectic polysaccharides. The CPF had higher concentrations of amino acids and a better balance of essential/non-essential amino acids, whereas the CPE exhibited higher concentrations of free amino acids, ensuring higher bioavailability. Both ingredients showed elevated mineral content, while heavy-metal concentrations remained within acceptable limits. This study established the bioactive potential of the CPF and the CPE, demonstrating the high content of caffeine and gallic, protocatechuic, and 4-caffeoylquinic acids. The toxicity studies revealed that the CPF and the CPE exhibited safety when orally administered to mice. Administered doses were non-toxic, as they did not induce lethality or adverse effects in the mice or produce significant histopathological or biochemical adverse changes. This study represents a first step in valorizing the CPF and the CPE as safe novel food ingredients with health benefits for functional and nutritional foods. [ABSTRACT FROM AUTHOR]

Polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emissions during the roasting of green Arabica coffee and coffee formulations containing alcohol, sugar, and honey were investigated in this study. Fast and slow roasting methods, which took 5.62 and 9.65 min to achieve a light roast, respectively, were used to evaluate the emissions. The concentrations in the flue gas during the fast roasting of green coffee (0.0296 ng Nm−3 and 0.00364 ng WHO-TEQ Nm−3) were 13.9% and 70.5% higher than during slow roasting, respectively. However, this was only the trend for some formulations, and no significant differences in concentrations were found between the methods at p = 0.05. Thus, the slow roasting method might not necessarily reduce formation when additives are included. The emission factors were 2.86 ng kg−1 and 0.352 ng WHO-TEQ kg−1, and 4.17 ng kg−1 and 0.176 ng WHO-TEQ kg−1 for the fast and slow roasting of green coffee, respectively. Further investigations are warranted to understand the formation mechanism, assess potential health risks, and explore mitigation strategies. These findings have implications for both coffee processing industries and regulatory bodies, as understanding the impact of roasting methods and additives could inform the development of cleaner production practices and targeted emission reduction policies. [ABSTRACT FROM AUTHOR]

Considering the health benefits of kombucha, already widely studied, the objective of this study was to develop kombucha beverages with the addition of an infusion of specialty arabica coffee from the first fermentation, varying the proportion of specialty coffee (2% to 13%), and evaluate their pH, volatile acidity, degree of alcohol, centesimal composition, sodium contents, and colour parameters to determine the acceptability of the beverages. Concerning the pH, all of the formulations conformed with the kombucha identity standard, but K3 (11% coffee) and K4 (13% coffee) were below the established minimum for volatile acidity. Except for K4, all of the other formulations were classified as alcoholic kombuchas, although their values were very close to the limit for non-alcoholic beverages. The formulations presented low sugar and sodium contents, which corroborated their low caloric value. Therefore, coffee-flavoured kombucha fermented for 18 days becomes an option for consumers looking for low-calorie, refreshing, and healthy drinks. The luminosity of the beverages decreased as the proportion of coffee increased, and consequently, the values for a* and b* increased, indicating a strong tendency for a yellowish-red colour. Sensorially, the formulations K4 and K3 were the most well accepted in all respects and can therefore be considered formulations with high commercialisation potential. [ABSTRACT FROM AUTHOR]

Research into microbial interactions during coffee processing is essential for developing new methods that adapt to climate change and improve flavor, thus enhancing the resilience and quality of global coffee production. This study aimed to investigate how microbial communities interact and contribute to flavor development in coffee processing within humid subtropical climates. Employing Illumina sequencing for microbial dynamics analysis, and high-performance liquid chromatography (HPLC) integrated with gas chromatography–mass spectrometry (GC-MS) for metabolite assessment, the study revealed intricate microbial diversity and associated metabolic activities. Throughout the fermentation process, dominant microbial species included Enterobacter, Erwinia, Kluyvera, and Pantoea from the prokaryotic group, and Fusarium, Cladosporium, Kurtzmaniella, Leptosphaerulina, Neonectria, and Penicillium from the eukaryotic group. The key metabolites identified were ethanol, and lactic, acetic, and citric acids. Notably, the bacterial community plays a crucial role in flavor development by utilizing metabolic versatility to produce esters and alcohols, while plant-derived metabolites such as caffeine and linalool remain stable throughout the fermentation process. The undirected network analysis revealed 321 interactions among microbial species and key substances during the fermentation process, with Enterobacter, Kluyvera, and Serratia showing strong connections with sugar and various volatile compounds, such as hexanal, benzaldehyde, 3-methylbenzaldehyde, 2-butenal, and 4-heptenal. These interactions, including inhibitory effects by Fusarium and Cladosporium, suggest microbial adaptability to subtropical conditions, potentially influencing fermentation and coffee quality. The sensory analysis showed that the final beverage obtained a score of 80.83 ± 0.39, being classified as a specialty coffee by the Specialty Coffee Association (SCA) metrics. Nonetheless, further enhancements in acidity, body, and aftertaste could lead to a more balanced flavor profile. The findings of this research hold substantial implications for the coffee industry in humid subtropical regions, offering potential strategies to enhance flavor quality and consistency through controlled fermentation practices. Furthermore, this study contributes to the broader understanding of how microbial ecology interplays with environmental factors to influence food and beverage fermentation, a topic of growing interest in the context of climate change and sustainable agriculture. [ABSTRACT FROM AUTHOR]

Spent coffee grounds (SCGs) constitute the main solid residue of the coffee brewing process. SCGs are generated in significant amounts daily, worldwide. The effective management of this waste through biological processes is still an unresolved problem. In this study, the application of hydrodynamic cavitation (HC) as a pre-treatment method for improving the biodegradability of SCGs suspended in municipal wastewater was proposed. An orifice plate with a conical concentric hole having inlet/outlet diameter of 3/10 mm was applied as the cavitation inducer. Three inlet pressures were chosen: 3, 5 and 7 bar. The effects in time intervals of 0, 5, 10, 20, 30 and 45 min were evaluated. The application of HC led to enhanced biodegradability for each case. The results of multi-criteria decision indicated that the most efficient combination in terms of biodegradability and energy usage was obtained at the pressure of 5 bar and duration of 20 or 30 min, depending on the adopted weights. The improvements of DOC/TOC (dissolved organic carbon/total organic carbon) ratio were 57% and 71%, as compared to the untreated samples. The release of caffeine was found at pressures of 5 and 7 bar. However, at 5 bar, this effect was noticed for the longest times, 30 and 45 min, respectively. [ABSTRACT FROM AUTHOR]

The metataxonomic diversity and microbial composition of microorganisms during the coffee fermentation process as well as their relationship with coffee quality were determined across 20 farms in the department of Cesar, Colombia, by sampling coffee fruits from Coffea arabica; Var. Castillo General®, Var. Colombia, and Var. Cenicafé 1. In each farm, the fruits were processed and the fermentation process took place between 10 and 42 h following this. Three samples of mucilage and washed coffee seeds were collected per farm during the fermentation process. The microorganisms present in the mucilage were identified using metataxonomic methods by amplifying the 16S rRNA gene for bacteria and ITS for fungi. The microorganisms' morphotypes were isolated and identified. The analysis of bacteria allowed for the identification of the following genera: Gluconobacter, Leuconostoc, Acetobacter, Frateuria, Pantoea, Pseudomonas, Tatumella, and Weisella, as well as unclassified enterobacteria; the Lactobacillacea and Secundilactobacillus families were only identified in the Var. Cenicafé 1. For fungi, the top 11 genera and families found included Hanseniaspora, Candida, Meyerozyma, Wickerhamomyces, Pichia, f-Saccharomycodaceae, f-Nectriciae, unclassified fungi, and Saccharomycetaceae, which were only found in Cenicafé 1. A total of 92% of the coffee samples obtained scored between 80.1 and 84.9, indicating "Very Good" coffee (Specialty Coffee Association (SCA) scale). Farms with the longest fermentation times showed better coffee attributes related to acidity, fragrance, and aroma. During coffee fermentation, there is a central microbiome. The differences between the microorganisms' genera could be influenced by the coffee variety, while the specific conditions of each farm (i.e., altitude and temperature) and its fermentation processes could determine the proportions of and interactions between the microbial groups that favor the sensory characteristics responsible for coffee cup quality. [ABSTRACT FROM AUTHOR]

The coffee fruit is preferably harvested at the cherry stage, with high moisture and metabolic activity, and must then undergo a drying process for better preservation of the bean and its sensory attributes. In this context, this study aimed to characterize the final quality of the Arara cultivar Arabica coffee processed using the wet method and subjected to six drying methods: three conducted at the agro-industrial establishment (fixed-bed dryer, rotary drum dryer, and combined drying) and three laboratory-scale methods (convective oven, cast-tape drying, and suspended terrace). Drying was carried out to reduce the coffee's moisture content from an initial value of 46.2% on a wet basis (w.b.) to a final average value of 11.35% (w.b.). The fruits of in natura demucilaged coffee and the processed dry coffee beans were characterized for moisture, ash content, nitrogen compounds, lipids, total titratable acidity, organic acids, sugars, and the instrumental color of the beans. The sensory profile of the Arabica coffee was evaluated by five coffee specialists using the methodology proposed by the Specialty Coffee Association (SCA), and all the coffees were classified as a specialty. [ABSTRACT FROM AUTHOR]

With its extensive production and consumption, the coffee industry generates significant amounts of lignocellulosic waste. This waste, primarily comprising coffee biomasses, is a potential source of cellulose. This cellulose can be extracted and utilized as a reinforcing agent in various biocomposites with polymer matrices, thereby creating high-value products. One such biodegradable polymer, Poly(butylene adipate-co-terephthalate) (PBAT), is notable for its properties that are comparable with low-density polyethylene, making it an excellent candidate for packaging applications. However, the wider adoption of PBAT is hindered by its relatively high cost and lower thermomechanical properties compared with conventional, non-biodegradable polymers. By reinforcing PBAT-based biocomposites with cellulose, it is possible to enhance their thermomechanical strength, as well as improve their water vapor and oxygen barrier capabilities, surpassing those of pure PBAT. Consequently, this study aims to provide a comprehensive review of the latest processing techniques for deriving cellulose from the coffee industry's lignocellulosic by-products and other coffee-related agro-industrial wastes. It also focuses on the preparation and characterization of cellulose-reinforced PBAT biocomposites. [ABSTRACT FROM AUTHOR]

Coffee processing generates a large amount of organic waste, which has the potential for energy use through biogas production. Although Brazil dominates world coffee production, treating its residue with biogas technology is not a practice, especially due to this product's seasonality, which hampers continuous digester operation. The implementation of biogas production from coffee residues in a concept of industrial symbiosis could overcome this. This work evaluates the biogas energy potential from the main liquid residues of coffee processing (i.e., mucilage and wash water) and their integration with glycerin and cattle manure. Around 2773 m3 biogas day−1 would be produced (75% CH4), used as biomethane (734 thousand m3 year−1), or thermal energy (23,000,000 MJ year−1), or electricity (2718 MWh year−1), which could supply, respectively, all the liquefied petroleum gas (LPG) and diesel demands of the farm, all the thermal energy demands of the grain drying process, as well as electricity for 30 residences. Considering the short coffee season, the results have a broader context for the application of biogas production on coffee processing farms, envisaging that the Agroindustrial Eco-Park concept has the potential to integrate various agroindustrial sectors for energy production, residue exchange, and water recirculation. [ABSTRACT FROM AUTHOR]

This study explores the variances in the organic, chemical, and sensory attributes of fermented coffee beans, specifically examining how post-harvest processes influence cup quality. Coffee fruits from the Catuaí IAC-144 variety were processed using both natural coffee (NC) and pulped coffee (PC) methods. The fruits were then subjected to self-induced anaerobic fermentation (SIAF) using one of the following fermentation methods: solid-state fermentation (SSF) or submerged fermentation (SMF). Within these methods, either spontaneous fermentation (SPF) or starter culture fermentation (SCF) was applied. Each method was conducted over periods of 24, 48, and 72 h. For this purpose, two-hundred-liter bioreactors were used, along with two control treatments. Numerous parameters were monitored throughout the fermentation process. A comprehensive chemical profiling and sensory analysis, adhering to the guidelines of the Specialty Coffee Association, were conducted to evaluate the influence of these fermentation processes on the flavor, aroma, and body characteristics of the coffee beverage across multiple dimensions. Data analysis and predictive modeling were performed using machine learning techniques. This study found that NC exhibited a higher production of acids (citric, malic, succinic, and lactic) compared to PC, resulting in distinct chemical and sensory profiles. The decision tree showed that fructose and malic and succinic acids were identified as the main factors enhancing sensory notes during cupping. SMF promoted higher concentrations of lactic acid, while SSF led to increased ethanol content. Consequently, the SIAF process enhances the sensory quality of coffee, adding value to the product by generating diverse sensory profiles. [ABSTRACT FROM AUTHOR]

Coffee is one of the most popular beverages worldwide, valued for its sensory properties as well as for its psychoactive effects that are associated with caffeine content. Nevertheless, coffee also contains antioxidant substances. Therefore, it can be considered a functional beverage. The aim of this study is to evaluate the influence of four selected post-harvest coffee fruit treatments (natural, full washed, washed–extended fermentation, and anaerobic) on the antioxidant and psychoactive properties of Arabica coffee. Additionally, the impact of coffee processing on the selected quality parameters was checked. For this purpose, results for caffeine content, total phenolic content (TPC), DPPH assay, pH, titratable acidity, and water content were determined. The results show that natural and anaerobic processing allow the highest caffeine concentration to be retained. The selection of the processing method does not have a significant influence on the TPC or antiradical activity of coffee. The identified differences concerning water content and pH along with lack of significant discrepancies in titratable acidity may have an influence on the sensory profile of coffee. [ABSTRACT FROM AUTHOR]

Coffee, a widely consumed beverage worldwide, undergoes postharvest methods that influence its physicochemical characteristics, while roasting modulates its composition, affecting sensory attributes. This study investigates the impact of distinct postharvest methods (washed and natural) on the antidiabetic activities, including α-amylase and DPP4, as well as the phytochemical profiling of geological indicator (GI) coffee beans (Coffea arabica L.). The results indicate notable differences in antidiabetic activity and phytochemical profiles between washed and natural processing methods. Coffee beans processed naturally exhibit significant suppression of DPP4 and α-amylase activities (p-value < 0.01) compared to beans processed using the washed technique. TLC profiling using the ratios of the solvent systems of ethyl acetate/dichloromethane (DCM) and acetone/DCM as separation solvents reveals dominant spots for the washed technique. LC-MS/MS-based untargeted metabolomics analysis using principle component analysis (PCA) clearly segregates samples processed by the natural and washed techniques without any overlap region. A total of 1114 phytochemicals, including amino acids and short peptides, are annotated. The natural processing of coffee beans has been shown to yield a slightly higher content of chlorogenic acid (CGA) compared to the washed processing method. Our findings highlight the distinct bioactivities and phytochemical compositions of GI coffee beans processed using different techniques. This information can guide consumers in choosing coffee processing methods that offer potential benefits in terms of alternative treatment for diabetes. [ABSTRACT FROM AUTHOR]

Coffee processing is solely centred around isolating the seed of this sweet and fragrant stone fruit. Isolating the fruit seed from the waste stream does not denote excellent cherry quality and does not provide optimal financial benefit to the farmer. Only a fruit-centred coffee process will be both commercially viable and sustainable, supporting the farmers and preserving nature. [ABSTRACT FROM AUTHOR]

Coffee (Coffea arabica), produced and marketed in Ecuador and worldwide, can be organoleptically improved by means of microorganisms such as well-characterized yeasts. This study aimed to isolate and characterize yeasts from three postharvest fermentation processes (i.e., Natural aerobic at room temperature; Carbonic maceration with a CO2 atmosphere at room temperature; and Carbonic refrigerated maceration with a CO2 atmosphere to 10 °C) of coffee fruits in Ecuador. Phenotypic and molecular analyses were conducted on 329 yeast isolates obtained from coffee farms in Loja, Olmedo, and Gonzanamá. Three universal media were used for yeast isolation diversity, and phenotypic characterization included morphology, sugar fermentation, salt tolerance, and ethanol resistance. Molecular characterization involved DNA analysis. The isolated diversity was classified into 12 morphotypes, nine distinct biochemical groups and nine genetic species. Only six species (i.e., Kurtzmaniella quercitrusa, Hanseniaspora opuntiae, Pichia. kluyveri, Torulaspora delbrueckii, T. quercuum, and Wickerhamomyces anomalus) identified phylogenetically corresponded to the designated morphotypes. But surprisingly, nine genetic species matched with the nine biochemical groups determined phenotypically analyzed using principal component analysis (PCA). Most of this diversity was found in the coffee plantation located in Gonzanamá, in contrast to Olmedo and Loja, without statistical significance (p value: 0.08295). On the other hand, the richness is not similar statistically (p value: 0.02991) between postharvest fermentation treatments. The findings suggest that the application of biochemical tests is useful for species determination, although morphological data may be ambiguous. Notably, Pichia kluyveri, detected in this study, holds potential for biotechnological evaluation in coffee fermentation processes. [ABSTRACT FROM AUTHOR]

Spent coffee waste is the most common by-product of coffee processing, and it has the potential to be used as a source of organic compounds for ruminant diets. The objective of this study was to evaluate the optimal inclusion level and method for using spent coffee waste (SCW) as a ruminant feed and investigate its effects on rumen fermentation characteristics and methane (CH4) production. The present in vitro batch culture study was conducted using two different experimental designs. The first experimental design (TRIAL. 1) was performed using a control diet of 500 mg of fresh matter basal diet (60% hay/40% concentrate), with SCW being used as a feed additive at 1%, 10% and 20% of the substrate. The second experimental design was performed using the same control diet, with spent coffee waste replacing either part of the hay (TRIAL. 2) or some of the concentrate mixture (TRIAL. 3) at four different dosages (30:70, 50:50, 70:30 and 100). When SCW was supplemented as a feed additive, there were increases in the production of volatile fatty acids and gas; however, it did not show any suppressive effects on CH4 production. In contrast, when SCW was included as a replacement for hay or concentrate, there were significant reductions in CH4 production with increasing levels of SCW inclusion. These reductions in CH4 production were accompanied by negative effects on nutrient digestibility and total volatile fatty acid production. These findings demonstrate that SCW could potentially be used as a prebiotic feed additive. Additionally, when SCW is used as a replacement for silage at 70:30 and 50:50 dosages appear to be feasible as a substitute for animal feed (hay and concentrate). [ABSTRACT FROM AUTHOR]

Fermented polymers like biobased poly(butylene succinate) (BioPBS) have become more relevant as technical substitutes for ductile petrochemical-based polymers but require biogenic functional additives to deaccelerate undesired thermo-oxidative degradation and keep a fully biobased character. In this paper, the influence of coffee parchment (PMT) from two different varieties and processings on the thermo-oxidative stabilization and mechanical properties of poly(butylene succinate) composites up to 20 wt.-% PMT were investigated. Micronized with a TurboRotor mill, both PMT powders differ in particle size and shape, moisture ab- and adsorption behavior and antioxidative properties. It could be shown that pulped-natural PMT consists partially of coffee cherry residues, which leads to a higher total polyphenol content and water activity. The homogeneous PMT from fully washed processing has a higher thermal degradation resistance but consists of fibers with larger diameters. Compounded with the BioPBS and subsequent injection molded, the fully washed PMT leads to higher stiffness and equal tensile strength but lower toughness compared to the pulped-natural PMT, especially at lower deformation speed. Surprisingly, the fully washed PMT showed a higher stability against thermo-oxidative decomposition despite the lower values in the total phenol content and antioxidative activity. The required antioxidative stabilizers might be extracted at higher temperatures from the PMT fibers, making it a suitable biogenic stabilizer for extrusion processes. [ABSTRACT FROM AUTHOR]

Coffee processing is a major contributor to the creation of food and product waste. Using coffee co-products can play an essential role in addressing environmental problems and issues with nutritionally unbalanced foods, population growth, and food-related diseases. This research aimed to determine the quality and sensory parameters (aw, pH, dry matter, TAC, TPC, fat, fatty acids profile, fiber, caffeine, chlorogenic acids, color, and sensory analysis) of different botanical origins of cascara (coffee husks) and silverskin (thin layer). The results of this study show that silverskin and cascara are a good source of TAC (1S 58.17 ± 1.28%, 2S 46.65 ± 1.20%, 1C 36.54 ± 1.84%, 2C 41.12 ± 2.11%). Cascara showed the presence of polyphenols (2C 49.135 g GAE·kg−1). Coffee co-products are good sources of fiber. Silverskin had higher values of caffeine than cascara. Palmitic, stearic, oleic, linoleic, and arachidic acids were the most represented acids in the samples. Given the obtained results, cascara can be considered "low-fat" (1C 4.240 g·kg−1 and 2C 5.4 g·kg−1). Based on the sensory evaluation, no sample reached the acceptable index value of 70%. Understanding the link between the character, identification properties, and composition of coffee co-products of different botanical origins can enable their application in the food industry. [ABSTRACT FROM AUTHOR]

Featured Application: The coffee processing industry is nowadays confronted with urgent challenges associated with the implementation of profitable and environmentally safe technological solutions for managing plant waste matter. Therefore, this sector of the food industry is cooperating with scientific communities to explore the possibility of using coffee by-products, especially spent coffee grounds, which can be considered as a valuable natural alternative to plant material with plentiful quantities of various components with antioxidant activity. However, additional investigations are needed to evaluate the potential for using spent coffee grounds in different forms as an ingredient of newly designed food products with functional properties or as a component of biodegradable packaging materials used in the agri-food processing system. These applications are in accordance with EU policies regarding the circular economy and sustainability of the food industry. The main goal of this research was to model and optimize the extraction process of bioactive compounds from spent coffee grounds (SCG). This study utilized response surface methodology (RSM) to determine the significance of the effects of independently tested extraction process conditions and their interactions. The quality of the SCG extracts was evaluated by performing the following determinations: total polyphenols content (TPC), ABTS and FRAP assays, browning index (BI), and caffeine and chlorogenic acids contents by high-performance liquid chromatography. The resultant optimal extraction conditions, which maximized recovery of antioxidant bioactive compounds, were 65% hydroethanolic solution (v/v) in a solvent–matrix ratio of 51 mL/g CS, followed by ultrasound-assisted extraction carried out for 30 min at 60 °C. The SCG extract obtained by this extraction variant had values for TPC, ABTS, FRAP and BI of approximately 38 mg GAE (gallic acid equivalent) per g d.m. SCG, 73 mg Trolox/g d.m. SCG, 81 µmol Fe (II)/g d.m. SCG, and 0.22, respectively. The sample was also characterized by a high content of caffeine (5 mg/g d.m. SCG) and chlorogenic acids (8 mg/g d.m. SCG). Based on the obtained results, SCG may be recognized as a coffee by-product that has abundant components with antioxidant activity and broad possible applications in agri-food processing fields. [ABSTRACT FROM AUTHOR]

Coffee silverskin (CS) is the thin epidermis covering and protecting the coffee bean and it represents the main by-product of the coffee roasting process. CS has recently gained attention due to its high content in bioactive molecules and the growing interest in valuable reutilization of waste products. Drawing inspiration from its biological function, here its potential in cosmetic applications was investigated. CS was recovered from one of the largest coffee roasters located in Switzerland and processed through supercritical CO2 extraction, thereby generating coffee silverskin extract. Chemical profiling of this extract revealed the presence of potent molecules, among which cafestol and kahweol fatty acid esters, as well as acylglycerols, β-sitosterol and caffeine. The CS extract was then dissolved in organic shea butter, yielding the cosmetic active ingredient SLVR'Coffee™. In vitro gene expression studies performed on keratinocytes showed an upregulation of genes involved in oxidative stress responses and skin-barrier functionality upon treatment with the coffee silverskin extract. In vivo, our active protected the skin against Sodium Lauryl Sulfate (SLS)-induced irritation and accelerated its recovery. Furthermore, this active extract improved measured as well as perceived skin hydration in female volunteers, making it an innovative, bioinspired ingredient that comforts the skin and benefits the environment. [ABSTRACT FROM AUTHOR]

Coffee waste is often viewed as a problem, but it can be converted into value-added products if managed with clean technologies and long-term waste management strategies. Several compounds, including lipids, lignin, cellulose and hemicelluloses, tannins, antioxidants, caffeine, polyphenols, carotenoids, flavonoids, and biofuel can be extracted or produced through recycling, recovery, or energy valorization. In this review, we will discuss the potential uses of by-products generated from the waste derived from coffee production, including coffee leaves and flowers from cultivation; coffee pulps, husks, and silverskin from coffee processing; and spent coffee grounds (SCGs) from post-consumption. The full utilization of these coffee by-products can be achieved by establishing suitable infrastructure and building networks between scientists, business organizations, and policymakers, thus reducing the economic and environmental burdens of coffee processing in a sustainable manner. [ABSTRACT FROM AUTHOR]

Coffee is the third-largest beverage with wide-scale production. It is consumed by a large number of people worldwide. However, acrylamide (AA) is produced during coffee processing, which seriously affects its quality and safety. Coffee beans are rich in asparagine and carbohydrates, which are precursors of the Maillard reaction and AA. AA produced during coffee processing increases the risk of damage to the nervous system, immune system, and genetic makeup of humans. Here, we briefly introduce the formation and harmful effects of AA during coffee processing, with a focus on the research progress of technologies to control or reduce AA generation at different processing stages. Our study aims to provide different strategies for inhibiting AA formation during coffee processing and investigate related inhibition mechanisms. [ABSTRACT FROM AUTHOR]

Coffee fermentation is a complex process, mainly involving bacteria and yeasts, whose interaction influences beverage quality. The way this process is conducted affects the interactions between these microorganisms. To identify microbial diversity in fermenting coffee, samples were collected from 20 farms in the Department of Quindío, Colombia. Metataxonomic analyses using high-throughput sequencing and volatile organic compound identification in green coffee beans were performed with HS-SPME and GC-MS. Potential relationships between some families and genera with different fermentation types and coffee quality were evaluated. In our results, samples presented with high richness and diversity were greater for bacteria than for yeast/fungi. The Enterobacteriaceae family dominated at the beginning of fermentation, while Leuconostoc, Lactobacillus, Gluconobacter, and Acetobacter genera dominated at the end, a finding related to pH reduction and final coffee quality. Overall, 167 fungal families were identified, but Saccharomyceaceae dominated from the beginning. Alcohols and esters were the main chemical classes identified in green coffee bean samples from these fermentations. These results will facilitate the identification process conditions that influence the presence and abundance of microorganisms related to quality as well as contributing to the design of strategies to conduct fermentations to improve the final quality of coffee. [ABSTRACT FROM AUTHOR]

Currently composites play an important role in all aspects of engineering and technology, with constantly growing applications. Recently, more attention was focused on natural fillers due to their suitability as reinforcement materials in thermo-plastic matrices which improve the mechanical properties of these polymers. Biofillers are used due to their low cost, high strength rigidity, non-toxicity, biodegradability, and availability. Currently, spent coffee grounds (SCG) are attracting more attention as a natural filler since high amounts of SCG are generated every day (food waste of coffee processing). This study allowed us to determine the long-term effect of activated sludge microorganisms with known technical and technological parameters on the mechanical properties of composites with spent coffee grounds filler. The fittings consisted of high-density poly-ethylene (PE-HD), which was used as the matrix, and a filler based on spent coffee grounds (SCG), which was used as a modifier. It was established that the composition of the composite and its residence time in the bioreactor directly influenced the contact angle value. The shift of the contact angle value is associated with the formation of the biofilm on the tested materials. An increase in the contact angle was observed in the case of all samples tested in the bioreactor, with the lowest values equal to approx. 76.4° for sample A (PE-HD) and higher values of approx. 90° for the remaining composite samples with a coffee grounds filler. The research confirmed that the increased ratio of coffee grounds in the composite results in the increased diversity and abundance of microorganisms. The highest number and the greatest diversity of microorganisms were observed in the case of the composite with 40% coffee grounds after more than a year of exposure in the bioreactor, while the composite with 30% SCG was second. Ciliates (Ciliata), especially the sessile forms belonging to the Epistylis genus, were the most common and the most numerous group of microorganisms in the activated sludge and in the biofilm observed on the samples after immersion in the bioreactor. The conducted research confirms that the use of polymer composite mouldings with a filler in the form of spent coffee grounds as a carrier allows the efficient increase in the population of microorganisms in the bioreactor. [ABSTRACT FROM AUTHOR]

The aim of this study was to detect and identify the volatile compounds in coffee that was obtained in defect roast processes versus standard roasting and to determine the type and strength of the correlations between the roast defects and the volatile compound profile in roasted coffee beans. In order to achieve this goal, the process of coffee bean roasting was set to produce an underdeveloped coffee defect, an overdeveloped coffee defect, and defectless coffee. The "Typica" variety of Arabica coffee beans was used in this study. The study material originated from a plantation that is located at an altitude of 1400–2000 m a.s.l. in Huehuetenango Department, Guatemala. The analyses were carried out with the use of gas chromatography/mass spectrometry (GC–MS) and an electronic nose. This study revealed a correlation between the identified groups of volatile compounds and the following coffee roasting parameters: the time to the first crack, the drying time, and the mean temperatures of the coffee beans and the heating air. The electronic nose helped to identify the roast defects. [ABSTRACT FROM AUTHOR]

An effect of a processing method (dry and wet) and a degree of roasting (light, medium, and dark) of 15 coffee (Coffea arabica) samples on the content of caffeine, chlorogenic acid (CQA), total polyphenols (TPP), acrylamide (AA), and on the colour parameters L*, a*, and b* was evaluated. Neither processing nor roasting affected caffeine content (p > 0.05). The degree of roasting accounted for 46% and 72% of explained variability of the CQA content and AA content, respectively (p < 0.05). AA content was in the range from 250 (wet-processed, light-roasted samples) to 305 µg·kg−1 (wet-processed, dark-roasted coffees), but the dark roasting only tended (p > 0.05) to increase AA content. Wet-processed, dry-roasted coffee had higher (p < 0.05) TPP content (48.5 mg·g−1) than its dry-processed, dry-roasted counterpart (42.5 mg·g−1); the method of processing accounted for 70% of explained variability of TPP. Both the method of processing and the degree of roasting affected the L*, a*, and b* values (p < 0.01), but the lower values (p < 0.05) of these parameters in the dark-roasted samples were found only within the wet processing. A negative correlation between the AA content and lightness (L*) was established (r = −0.39, p < 0.05). It was concluded that from the consumers' viewpoint, the results of the present study indicate relatively small differences in quality parameters of coffee irrespective of the method of processing or degree of roasting. [ABSTRACT FROM AUTHOR]

This study examines sustainability and gender dynamics of coffee value-chain development intervention in Ethiopia. The data were collected from male and female farmers and other stakeholders using key informant interviews, focus group discussions, and a questionnaire survey. The study found that some of the introduced technologies/practices were adopted and sustained whereas others were dropped or adapted depending on technical, institutional, and socio-economic factors. The value-chain intervention was generic and not gender-sensitive. Although the intervention generated positive changes and benefits for all household members (by improving coffee quality, market access, and their income), it had mixed outcomes for women. Although women were not primarily targeted by the intervention, their increased involvement in coffee harvesting and processing fostered women's skills, confidence, and decision-making power. However, some of the new technologies/practices required additional labour, while others were labour saving and eased their work. As a result of increasing the wholesale trading of coffee, the role for marketing largely shifted to men. This study underscores the need for a proper gender analysis and embedding gender-sensitive approaches in designing development interventions to ensure women's fair representation, and thus equitable and sustainable benefits. Such efforts should entail a paradigm shift from production to promoting women's role and integration into the entire value chain, as well as improving their access to productive resources and services. Moreover, value-chain development interventions should consider technical, institutional, social, and economic factors that could influence their effectiveness and sustainability. [ABSTRACT FROM AUTHOR]

Coffee cascara is the first and most significant by-product of the coffee processing industry, whose valorization has become an urgent priority to reduce harmful environmental impacts. This work aimed to provide an improved understanding of phytochemicals and polysaccharides in coffee cascara in order to offer information for the better evaluation of potential applications. Phytochemicals in 20 different coffee cascara samples were ultrasonically extracted and analyzed by HPLC-UV and HPLC-MS/MS. Four novel compounds were isolated for the first time from coffee cascara, including two still unknown tautomers (337 Da), and two dihydroflavonol glycosides (dihydromyricetin glycoside and dihydromyricetin rhamnosylglycoside). Their presence can contribute to the design of new value-added applications of coffee cascara. Chemical characterization of two polysaccharides from two of the coffee cascara pulp samples showed that they were mainly composed of homogalacturonan, with rhamnose and arabinose as minor neutral sugars. In addition, principal component analysis results indicated that coffee cultivar and/or country significantly impacted the phytochemical composition of coffee cascara, although differences may be reduced by the external environment and processing method. It is suggested that processing method should be carefully designed when generating coffee cascara from the same cultivar and country/farm. [ABSTRACT FROM AUTHOR]

Metabolomic tecniques have already been used to characterize two of the most common coffee species, C. arabica and C. canephora, but no studies have focused on the characterization of green and roasted coffee varieties of a certain species. We aim to provide, using NMR-based metabolomics, detailed and comprehensive information regarding the compositional differences of seven coffee varieties (C. arabica) of green and roasted coffee bean batches from Nicaragua. We also evaluated how different varieties react to the same post-harvest procedures such as fermentation time, type of drying and roasting. The characterization of the metabolomic profile of seven different Arabica varieties (Bourbon-typica), allowed us also to assess the possible use of an NMR spectra of bean aqueous extracts to recognize the farm of origin, even considering different farms from the same geographical area (Nueva Segovia). Here, we also evaluated the effect of post-harvest procedures such as fermentation time and type of drying on green and roasted coffee, suggesting that post-harvest procedures can be responsible for different flavours. This study provides proof of concept for the ability of NMR to phenotype coffee, helping to authenticate and optimise the best way of processing coffee. [ABSTRACT FROM AUTHOR]

Coffee pulp, mucilage, and beans with mucilage were used to develop alcoholic beverages. The pulp of 45.3% pulp, 54.7% mucilage with seed, and 9.4% mucilage only were obtained during the wet processing of coffee. Musts were prepared for all to TSS (Total soluble solid) 18 ◦Bx and fermentation was carried out for 12–16 days until TSS decreased to 5 ◦Bx at 30 ◦C. Phenolic characteristics, chromatic structures, chemical parameters, and sensory characteristics were analyzed for the prepared alcoholic beverages. Methanol content, ester content, aldehyde, alcohol, total acidity, caffeine, polyphenols, flavonoids, chromatic structure, and hue of the alcoholic beverage from the pulp was 335 mg/L, 70.58 ppm, 9.15 ppm, 8.86 ABV%, 0.41%, 30.94 ppm, 845.7 mg GAE/g dry extract, 440.7 mg QE/g dry extract, 0.41, and 1.71, respectively. An alcoholic beverage from the pulp was found superior to an alcoholic beverage from mucilage with beans and a beverage from mucilage in sensory analysis. There is the possibility of developing fermented alcoholic beverages from coffee pulp and mucilage. However, further research is necessary for quality of the beans that were obtained from the fermentation with the mucilage. [ABSTRACT FROM AUTHOR]

Featured Application: This work deals with the development of an activated carbon adsorber via the exploitation of spent coffee waste. Economic and environmental benefits from such processes are extended. The application on hexavalent chromium removal was tested. Hexavalent chromium (Cr(VI)) is a heavy metal that is highly soluble and exhibits toxic effects on biological systems. Nevertheless, it is used in many industrial applications. The adsorption process of Cr(VI), using activated carbon (AC), is under investigation globally. On the other hand, around six million tons of spent coffee is sent to landfill annually. In the spirit of cyclic economy, this research investigated the production of AC from spent coffee for the removal of Cr(VI) from wastewater. The AC was produced via pyrolysis process under a nitrogen atmosphere. Chemical activation using potassium hydroxide (KOH) occurred simultaneously with the pyrolysis process. The produced AC was tested as an absorber of Cr(VI). The best fitted kinetic model was the diffusion–chemisorption model. A 24-h adsorption experiment was carried out using a solution with a pH of 3 and an initial Cr(VI) concentration of 54.14 ppm. This resulted in an experimental maximum capacity of 109 mg/g, while the theoretical prediction was 137 mg/g. It also resulted in an initial adsorption rate (ri) of 110 (mg/(g h)). The Brunauer–Emmett–Teller surface area (SgBET) was 1372 m2/g, the Langmuir surface area (SgLang.) was 1875 m2/g, and the corrugated pore structure model surface area (SgCPSM) was 1869 m2/g. The micropore volume was 84.6%, exhibiting micropores at Dmicro1 = 1.28 and Dmicro2 = 1.6 nm. The tortuosity factor (τ) was 4.65. [ABSTRACT FROM AUTHOR]

Removal of the mucilage layer of coffee fruits by a fermentation process has became an interesting strategy to improve coffee quality, which is able to assist the formation of flavored molecules. In this study, four sets of inoculation protocols were evaluated using ripe and immature coffee fruits, respectively, including (i) pure culture fermentation with Pichia fermentans, (ii) pure culture fermentation with Pediococcus acidilactici, (ii) combined fermentation with P. fermentans and P. acidilactici, and (iv) spontaneous, non-inoculated control. The initial pulp sugar concentration of ripe coffee fruits (0.57 and 1.13 g/L glucose and fructose content, respectively) was significantly higher than immature coffee pulp (0.13 and 0.26 g/L glucose and fructose content, respectively). Combined inoculation with P. fermentans and P. acidilactici of ripe coffee beans increased pulp sugar consumption and production of metabolites (lactic acid, ethanol, and ethyl acetate), evidencing a positive synergic interaction between these two microbial groups. On the other hand, when immature coffee fruits were used, only pure culture inoculationwith P. fermentans was able to improve metabolite formation during fermentation, while combined treatment showed no significant effect. Altogether, 30 volatile compounds were identified and semi-quantified with HS- solid phase microextraction (SPME)-gas chromatography coupled to mass spectrophotometry (GC/MS) in fermented coffee beans. In comparison with pure cultures and spontaneous process, combined treatment prominently enhanced the aroma complexity of ripe coffee beans, with a sharp increase in benzeneacetaldehyde, 2-heptanol, and benzylalcohol. Consistent with the monitoring of the fermentation process, only P. fermentans treatment was able to impact the volatile composition of immature coffee beans. The major impacted compounds were 2-hexanol, nonanal, and D-limonene. In summary, this study demonstrated the great potential of the combined use of yeast and lactic acid bacteria to improve fermentation efficiency and to positively influence the chemical composition of coffee beans. Further studies are still required to investigate the mechanisms of synergism between these two microbial groups during the fermentation process and influence the sensory properties of coffee products. [ABSTRACT FROM AUTHOR]

Primary coffee processing generates important by-products—the pulp, husk and mucilage—while producing the green coffee beans. These by-products represent a large quantity of biomass and might create an adverse impact on environment if they are left to uncontrolled natural decay. In this study, the bio-methane formation potential of coffee husk, pulp and mucilage was examined in batch assays performed at 21 °C, 30 °C and 37 °C. The mean specific methane yield (SMY) from husk, pulp, and mucilage were 159.4, 244.7 and 294.5 L kg−1 volatile solids(VS), respectively, for a fermentation temperature of 37 °C; 156.8, 234.8 and 287.1 L kg−1 VS, respectively, for 30 °C; and 139.9, 196.2 and 255.9 L kg−1 VS, respectively, for 21°C. Two kinetic models, namely, the modified Logistic model (LOG) and the modified Gompertz model (GOM), were applied to fit experimental data and the respective kinetic constants were generated. Both models exhibited a very good fit to the measured data points (R2 > 0.987). The relationship of kinetic constants of substrates with fermentation temperatures was established and inserted into the LOG and GOM models; thus, generalized LOG and GOM models were obtained to predict SMY of the substrates at any temperature between 21 °C and 37 °C. [ABSTRACT FROM AUTHOR]

Coffea liberica presents the smallest proportion of cultivated coffee worldwide. Its taste varies highly from C. arabica spp. or C. canephora spp. As the unfermented taste of C. liberica is often described as lactic, and animalic with aromatics of blue cheese, fermentation experiments of C. liberica coffee cherries were conducted. Coffee cherry fermentation is carried out to modify and enhance the sensory profile of green and roasted coffee beans. Various microorganisms change the composition of organic precursor compounds, reducing off-flavours during green bean coffee processing and roasting. For the comparison of the sensory properties of fermented coffee beans, SCA-trained experts grade the coffees by specific sensory attributes. Roasted and ground coffee powder, as well as ground raw coffee samples, were analysed by headspace-gas chromatography–mass spectrometry/ion mobility spectrometry (GC-MS/IMS) to determine the volatile fingerprint of unfermented and fermented C. liberica coffee. Eight different unfermented C. liberica samples were analysed and the volatile profiles compared to those of arabica spp. and canephora spp. The unfermented coffee beans differ in origin and processing. Furthermore, single-origin C. liberica fermented with two different wine yeasts was compared to unfermented C. liberica. The fermented coffee beans share the same variety, processing, and profile of roasting and differ only in their origin and fermentation inoculum. This study presents the direct comparison of the aromatic fingerprint measured in the instrument. Compound regions in the spectra associated with different coffee species and ferments are shown. The potential of GC-IMS for fast comparison of the aromatic fingerprint is demonstrated. [ABSTRACT FROM AUTHOR]

This work aims to study the removal of Cu(II) and Cr(VI) from aqueous solutions with commercial coffee wastes. Materials with no further treatment such as coffee residues from café may act as adsorbents for the removal of Cu(II) and Cr(VI). Equilibrium data were successfully fitted to the Langmuir, Freundlich and Langmuir-Freundlich model (L-F). The maximum adsorption capacity of the coffee residues can reach 70 mg/g for the removal of Cu(II) and 45 mg/g for Cr(VI). The kinetic data were fitted to pseudo-first, -second and -third order equations. The equilibrium was achieved in 120 min. Also, the effect of pH on adsorption and desorption was studied, as well as the influence of agitation rate. Ten cycles of adsorption-desorption were carried out revealing the strong reuse potential of these low-cost adsorbents; the latter was confirmed from a brief economic approach [ABSTRACT FROM AUTHOR]

The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma. [ABSTRACT FROM AUTHOR]

Spent coffee grounds (SCGs) generated in coffee processing for beverages and other products are a very significant organic residue that needs to be properly treated. Waste valorization via oil extraction has the potential to obtain compounds that can be used for producing biodiesel or other high-value products, such as polymers. This work focuses on the ultrasound-assisted extraction of SCG oil using n-hexane as a solvent. Three key process parameters are analyzed: temperature, extraction time, and liquid/solid (L/S) rate of solvent, using a central composite rotatable design (CCRD), an analysis that, to the author's knowledge, is not yet available in the literature. The data were analyzed using the software StatSoft STATISTICA 13.1 (TIBCO Software Inc., Palo Alto, CA, USA). Results show that all parameters have a statistical influence on the process performance (p < 0.05), being the L/S ratio the most significant, followed by extraction time and temperature. An analysis of variance (ANOVA) showed that the empirical model is a good fit to the experimental data at a 95% confidence level. For the range of conditions considered in this work, the optimal operating conditions for obtaining an oil extraction yield in the range of 12 to 13%wt are a solvent L/S ratio of around 16 mL g−1, for a temperature in the range of 50 to 60 °C, and the longest contact time, limited by the process economics and health and safety issues and also, by the n-hexane boiling temperature. [ABSTRACT FROM AUTHOR]

Coffee is consumed not just for its flavor, but also for its health advantages. The quality of coffee beverages is affected by a number of elements and a series of processes, including: the environment, cultivation, post-harvest, fermentation, storage, roasting, and brewing to produce a cup of coffee. The chemical components of coffee beans alter throughout this procedure. The purpose of this article is to present information about changes in chemical components and bioactive compounds in coffee during preharvest and postharvest. The selection of the appropriate cherry maturity level is the first step in the coffee manufacturing process. The coffee cherry has specific flavor-precursor components and other chemical components that become raw materials in the fermentation process. During the fermentation process, there are not many changes in the phenolic or other bioactive components of coffee. Metabolites fermented by microbes diffuse into the seeds, which improves their quality. A germination process occurs during wet processing, which increases the quantity of amino acids, while the dry process induces an increase in non-protein amino acid γ-aminobutyric acid (GABA). In the roasting process, there is a change in the aroma precursors from the phenolic compounds, especially chlorogenic acid, amino acids, and sugars found in coffee beans, to produce a distinctive coffee taste. [ABSTRACT FROM AUTHOR]

To obtain the coffee beverage, approximately 90% of the edible parts of the coffee cherry are discarded as agricultural waste or by-products (cascara or husk, parchment, mucilage, silverskin and spent coffee grounds). These by-products are a potential source of nutrients and non-nutrient health-promoting compounds, which can be used as a whole ingredient or as an enriched extract of a specific compound. The chemical composition of by-products also determines food safety of the novel ingredients. To ensure the food safety of coffee by-products to be used as novel ingredients for the general consumer population, pesticides, mycotoxins, acrylamide and gluten must be analyzed. According with the priorities proposed by the Food Agriculture Organization of the United Nations (FAO) to maximize the benefit for the environment, society and economy, food waste generation should be avoided in the first place. In this context, the valorization of food waste can be carried out through an integrated bio-refinery approach to produce nutrients and bioactive molecules for pharmaceutical, cosmetic, food and non-food applications. The present research is an updated literature review of the definition of coffee by-products, their composition, safety and those food applications which have been proposed or made commercially available to date based on their chemical composition. [ABSTRACT FROM AUTHOR]

This article studies the environmental impacts of cellulase production by using a comparative attributional life cycle assessment (LCA) of two different scenarios of production. The first one is the commonly used submerged fermentation (SmF) using a pure substrate (cellulose powder) and a specific microorganism (Trichoderma reesei). The second scenario considers a novel system to produce enzymes and simultaneously treat a waste using the solid-state fermentation (SSF) process of coffee husk (CH) used as substrate. Experimental data were used in this scenario. The complete production process was studied for these two technologies including the fermentation phase and the complete downstream of cellulase. Life cycle inventory (LCI) data were collected from the database EcoInvent v3 (SimaPro 8.5) modified by data from literature and pilot scale experiments. The environmental impacts of both production systems revealed that those of SmF were higher than those of SSF. A sensitivity analysis showed that the results are highly conditioned by the energy use in the form of electricity during lyophilization, which is needed in both technologies. The results point to a possible alternative to produce the cellulase enzyme while reducing environmental impacts. [ABSTRACT FROM AUTHOR]

Process control with high time resolution is essential to maintain high product quality in coffee roasting. However, analytical techniques for quality assurance or measurements of desired coffee properties are often labor-intensive and can only be conducted after dropping the coffee beans. Resonance-enhanced multi-photon ionization time-of-flight mass spectrometry (REMPI-TOFMS) at 248 nm and 266 nm was applied to analyze the composition of the roast gas from small-scale Arabica coffee roasting. Coffee beans were dropped after different roasting times, ground and analyzed by Colorette to obtain the roast degree. Additionally, the antioxidant capacity of the coffee brew was determined by Folin–Ciocalteu (FC) assay. Models for the prediction of Colorette and FC values from REMPI mass spectra were constructed by partial least squares (PLS) regression. REMPI-TOFMS enables the prediction of Colorette values with a root-mean-square error in prediction (RMSEP) below 5 for both wavelengths. FC values could be predicted using REMPI at 248 nm with an RMSEP of 80.3 gallic acid equivalents (GA-eq) mg L−1, while REMPI at 266 nm resulted in RMSEP of 151 GA-eq mg L−1. Finally, the prediction of Colorette and FC value at 5 s time resolution were demonstrated with online measurements. [ABSTRACT FROM AUTHOR]

An untargeted metabolomics strategy using hydrophilic interaction chromatography-mass spectrometry (HILIC-MS) was developed in this work enabling the study of the coffee roasting process. Green coffee beans and coffee beans submitted to three different roasting degrees (light, medium, and strong) were analyzed. Chromatographic separation was carried out using water containing 10 mM ammonium formate with 0.2 % formic acid (mobile phase A) and acetonitrile containing 10 mM ammonium formate with 0.2 % formic acid (mobile phase B). A total of 93 molecular features were considered from which 31 were chosen as the most statistically significant using variable in the projection values. 13 metabolites were tentatively identified as potential biomarkers of the coffee roasting process using this metabolomic platform. Results obtained in this work were complementary to those achieved using orthogonal techniques such as reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) and capillary electrophoresis-mass spectrometry (CE-MS) since only one metabolite was found to be common between HILIC-MS and RPLC-MS platforms (caffeoylshikimic acid isomer) and other between HILIC-MS and CE-MS platforms (choline). On the basis of these results, an untargeted metabolomics multiplatform is proposed in this work based on the integration of the three orthogonal techniques as a powerful tool to expand the coverage of the roasted coffee metabolome. [ABSTRACT FROM AUTHOR]

Soluble coffee offers the combined benefits of high added value and practicality for its consumers. The hydrolysis of coffee polysaccharides by the biochemical route, using enzymes, is an eco-friendly and sustainable way to improve the quality of this product, while contributing to the implementation of industrial processes that have lower energy requirements and can reduce environmental impacts. This work describes the production of hydrolytic enzymes by solid-state fermentation (SSF), cultivating filamentous fungi on waste from the coffee industry, followed by their application in the hydrolysis of waste coffee polysaccharides from soluble coffee processing. Different substrate compositions were studied, an ideal microorganism was selected, and the fermentation conditions were optimized. Cultivations for enzymes production were carried out in flasks and in a packed-bed bioreactor. Higher enzyme yield was achieved in the bioreactor, due to better aeration of the substrate. The best β-mannanase production results were found for a substrate composed of a mixture of coffee waste and wheat bran (1:1 w/w), using Aspergillus niger F12. The enzymatic extract proved to be very stable for 24 h, at 50 °C, and was able to hydrolyze a considerable amount of the carbohydrates in the coffee. The addition of a commercial cellulase cocktail to the crude extract increased the hydrolysis yield by 56%. The production of β-mannanase by SSF and its application in the hydrolysis of coffee polysaccharides showed promise for improving soluble coffee processing, offering an attractive way to assist in closing the loops in the coffee industry and creating a circular economy. [ABSTRACT FROM AUTHOR]