Coffee Residue Research Articles

Chitosan/coffee residue composite beads for removal of reactive dye

The adsorption performance of chitosan beads was investigated after coffee residue blending for the removal of Reactive Red 152 as an anionic dye. The study of the dye removal of chitosan/coffee residue composite beads as a function of coffee residue concentration indicated that mass ratio of chitosan to coffee residue of 60/40 was the most useful for enhancing the dye removal. The effects of contact time, initial pH, and adsorbent dosage on the adsorption efficiency were investigated systematically. The equilibrium adsorption isotherm of chitosan/coffee residue composite beads exhibited better fit to the Langmuir isotherm model than to the Freundlich isotherm model. The maximum adsorption capacity of composite bead was 4.27 mg/g. The dye desorption of composite bead was 24.83%. SEM images confirm that after adsorption the dye were dispersed onto the composite bead surface. This study demonstrated that the chitosan/coffee residue composite can effectively remove reactive dye from aqueous solution and simply with low cost.

Optimization of Hot-water Extraction Conditions of Bioactive Compounds from Coffee Residue Extracts

커피침출 공정의 부산물인 커피박을 이용한 고부가가치 식품 및 화장품 소재 생산을 위해 열수추출 공정의 폴리페놀 추출인자(용매, 온도, 시간, 농도) 최적화를 수행하였다. 실험에 적용 된 모든 추출인자가 폴리페놀 생산에 유의한 효과가 있음을 확인할 수 있었고 NaOH 농도가 폴리페놀 생산에 미치는 효과가 가장 큰 것...

APORTE DE Tithonia diversifolia ENABONOS ORGÁNICOS: EFECTO EN PRODUCCIÓN Y SUELO EN CAUCA, COLOMBIA

The contribution of Tithonia diversifolia to the composting of coffee residues and the effect on the production of chard and soil was evaluated, in order to improve the quality of the organic fertilizer and the use of the resources of the farm. 4 compostes were made from coffee pulp, banana tree trunk, gallinaza, adding 3 different amounts of T. diversifolia; Chemical composition, microbiological analysis and nutrient supply were determined. A randomized complete block design was used with three replicates and four treatments varying the amount of gold button T1: 50% coffee pulp, 25% chicken manure, 25% banana stump; T2: with 20% of Gold Button; T3: with 33% of Gold Button, and T4: with 50% of Gold Button. The evaluated variables were plant height, number of leaves and weight per plant in two cycles of planting. It was determined that the highest increase in chard yield was obtained in T3 and T4 containing more Tithonia diversifolia. In addition, the application of composting improves the soil chemical properties by increasing CIC, pH, N, K y Si.

A review for coffee adsorbents

Abstract This review examines the performance of new highly promising materials in water purification industry. Low-cost and effective industrial wastes may have ample applications in water decontamination procedures, the most popular of which is the biosorption, a metabolically passive process. Coffee residues are by-products produced in considerable quantities worldwide. Recently available researches show an expanding applicability of coffee by-products in the wastewater treatment. The food industry, the agriculture and aquaculture, the medicine and the cosmetics are indicatively some of the industries that discharge significant quantities of toxic substances through their wastewaters. Dyes and heavy metals are among the most typical chemicals of aforementioned wastewaters, with various harmful effects on living organisms. The current work collects information from recently published researches discussing the potential of raw or modified coffee residues for wastewater decontamination. Important adsorption stages such as (i) equilibrium (isotherms), (ii) kinetic, and (iii) desorption are also compared. Moreover, crucial factors affecting the adsorption process, such as the effect of solution pH, contact time, temperature and adsorbent's dose, are also mentioned.

Characterizations of biochar from hydrothermal carbonization of exhausted coffee residue

The aim of this study was to produce renewable energy from exhausted coffee residue, which is a form of biomass. As coffee preference continues to increase, the importation of coffee beans has been increasing sharply. However, the amount of coffee that is actually consumed is only about 0.2% of coffee beans, while the spent coffee beans are discarded in the form of exhausted coffee residue. Hydrothermal carbonization is a method of producing an improved fuel from renewable energy sources by changing the physical and chemical properties of biochars. Biochars were obtained from a variety of reaction temperatures during hydrothermal carbonization and analyzed using elemental analysis, ultimate analysis, and calorific value measurement. The atomic C/O and C/H ratios of all obtained biochars decreased and were found to be similar to those of lignite and sub-bituminous coal. The highest energy recovery efficiency of biochar indicates that the optimum reaction temperature for hydrothermal carbonization was between 210 and 240 °C, which produced biochars with calorific value of approximately 26–27 MJ/kg. The spectra of biochars obtained from Fourier transform infrared spectroscopy (FTIR) showed fewer C–O and aliphatic C–H functional groups, but more carbonyl C=O functional groups and aliphatic CH x groups. The results of this study indicate that hydrothermal carbonization can be used as an effective means to generate highly energy-efficient renewable fuel resources from coffee residue. The thermogravimetric analysis provided the changing combustion characteristics due to increased fixed carbon content.

Food Industry Co-streams: Potential Raw Materials for Biodegradable Mulch Film Applications

Vast amounts of co-streams are generated from plant and animal-based food processing industries. Efficient utilization of these co-streams is important from an economic and environmental perspective. Non-utilization or under-utilization of co-streams results in loss of potential revenues, increased disposal cost of these products and environmental pollution. At present, extensive research is taking place around the globe towards recycling of co-streams to generate value-added products. This review evaluates various co-streams from food processing industries as raw materials in developing biodegradable agricultural mulching applications. Among the agriculture-based co-streams, potato peels, tomato peels, carrot residues, apple pomace, coffee residues and peanut residues were reviewed with respect to production amount, composition, film forming components and film forming capabilities. Similarly, selected co-streams from slaughterhouses, poultry and fish processing industries were also reviewed and evaluated for the same purpose.

Bio-ethanol production from wet coffee processing waste in Ethiopia.

Large amounts of coffee residues are generated from coffee processing plants in Ethiopia. These residues are toxic and possess serious environmental problems following the direct discharge into the nearby water bodies which cause serious environmental and health problems. This study was aimed to quantify wet coffee processing waste and estimate its bio-ethanol production. The study showed that the wastes are potential environmental problems and cause water pollution due to high organic component and acidic nature. The waste was hydrolyzed by dilute H2SO4 (0.2, 0.4, 0.6, 0.8 and 1 M) and distilled water. Total sugar content of the sample was determined titrimetrically and refractometry. Maximum value (90%) was obtained from hydrolysis by 0.4 M H2SO4. Ethanol production was monitored by gas chromatography. The optimum yield of ethanol (78%) was obtained from the sample hydrolyzed by 0.4 M H2SO4 for 1 h at hydrolysis temperature of 100 °C and after fermentation for 24 h and initial pH of 4.5. Based on the data, it was concluded that reuse of the main coffee industry wastes is of significant importance from environmental and economical view points. In conclusion, this study has proposed to utilize the wet coffee processing waste to produce bio-ethanol which provides the alternative energy source from waste biomass and solves the environmental waste disposal as well as human health problem.

Valorization of coffee industry residues by subcritical water hydrolysis: Recovery of sugars and phenolic compounds

Two abundant coffee waste residues (powder and defatted cake) were treated using subcritical water (SubCW) for hydrolysis and extraction of reducing sugars (RS), total reducing sugars (TRS), and total phenolic compounds (TPC) under semi-continuous flow conditions. The flow-through process was carried out at 150, 175, 200 and 250°C, with a water flow of 10mL/min and reaction pressures of either 22.5 or 30MPa. For treated coffee powder, the maximum observed sugar recovery was 6.3% for RS (150°C and 30MPa) and 9.0% for TRS (150°C and 30MPa). The maximum TPC recovery was 26.64mg GAE (Gallic Acid Equivalent)/g powder coffee, observed at 200°C and 22.5MPa. For the defatted coffee cake, the maximum sugar yields were 8.79% and 17.23% for RS and TRS; both observed at a treatment temperature of 175°C. The highest TPC yield was 55.31mg TPC GAE/g defatted coffee cake, also at 175°C. HPLC was used to quantify specific carbohydrates (arabinose, cellobiose, glucose, and xylose), 5-hydroxy-methyl-furfural (5-HMF) and furfural in both coffee waste hydrolyzates, providing evidence of thermal degradation of the coffee carbohydrates. Scanning electron microscopy of the treated samples revealed particles deposited on the surface and other signs of physical degradation of the biomass structure. Fourier Transform Infrared Spectroscopy of the residues revealed that the density of surface bound acid groups increased with increasing treatment temperature. The results presented here provide a basis for the use of subcritical water to obtain reducing sugars and phenolic compounds from coffee residue.

A Study of Antioxidative and Antimicrobial Effects of Coffee Residue Extracts

A Study of Antioxidative and Antimicrobial Effects of Coffee Residue Extracts

Fixed-bed-column Studies for Methylene Blue Removal and Recovery by Untreated Coffee Residues

This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the continuous fixed-bed column system, two common models, namely (a) Bohart and Adams and (b) Clark were implemented. The Bohart and Adams capacity was up to N = 46,166 mg·L-1 or q0 = 104.5 mg·g-1 for bed-depth 15 cm, initial dye concentration 800 mg·L-1 and flow rate 20 mL·min-1. The results revealed that the Methylene Blue is fairly adsorbed on coffee residues. Consequently, this process can be applied as a low cost technique for cleaning basic dyes from the aquatic environment.

Fixed-Bed-Column Studies for Methylene Blue Removal and Recovery by Untreated Coffee Residues

This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the continuous fixed-bed column system, two common models, namely (a) Bohart and Adams and (b) Clark were implemented. The Bohart and Adams capacity was up to N = 46,166 mg·L-1 or q0 = 104.5 mg·g-1 for bed-depth 15 cm, initial dye concentration 800 mg·L-1 and flow rate 20 mL·min-1. The results revealed that the Methylene Blue is fairly adsorbed on coffee residues. Consequently, this process can be applied as a low cost technique for cleaning basic dyes from the aquatic environment.

Study of mechanical and physical properties of LLDPE-G-MA injection grade reinforced with coffee husk post-industrial waste

In this work, the evaluation of a post-industrial residue of coffee industry (coffee husk) as organic filler in functionalised linear low-density polyethylene matrix was investigated. The properties of these composites were compared with more widely used inorganic fillers, such as calcium carbonate and SiO2. All the composites were prepared by grafting of linear low-density polyethylene maleic anhydride and then by melt mixing of fillers. The rheological behaviour of the compounds during processing was established to evaluate the effects of a nanosized (SiO2), micron sized calcium carbonate and coffee husk fillers. Additionally, thermal, morphological and mechanical properties of the polymer composites were evaluated. The results indicated an increase in tensile modulus and tensile strength resulting from incorporation of fillers in the polymer matrix. Some relevant modifications of melting temperature and crystallinity degree for coffee husk composites were observed, but not observed for inorganic fillers composites. The properties of the composites prepared with coffee husk were comparable to those obtained with inorganic fillers, demonstrating that this coffee residue can be used as filler for obtaining composites for many possible applications.

Antioxidant Effect of Extracts from the Coffee Residue in Raw and Cooked Meat.

The residue of ground coffee obtained after the brewing process (spent coffee) still contains various functional components with high antioxidant capacity and health benefits, but no attempts have been made to use it as a resource to produce value-added food ingredients. This study evaluates the antioxidant activity of ethanol or hot water extracts from the residues of coffee after brewing. An extraction experiment was carried out using the conventional solid–liquid methods, including ethanol and water as the extraction media at different temperatures and liquid/solid ratios. The antioxidant activity of extracts was tested for total phenolic compound (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2-thiobarbituric acid reactive substances (TBARS) using oil emulsion and raw/cooked meat systems. The DPPH radical scavenging activity of the ethanol extracts with heating (HEE) and without heating (CEE) were higher than that of the hot water extracts (WE). The highest DPPH value of HEE and CEE at 1000 ppm was 91.22% and 90.21%, respectively. In oil emulsion and raw/cooked systems, both the water and ethanol extracts had similar antioxidant effects to the positive control (BHA), but HEE and CEE extracts showed stronger antioxidant activities than WE extract. These results indicated that the ethanol extracts of coffee residue have a strong antioxidant activity and have the potential to be used as a natural antioxidant in meat.

Pyrolysis of Agroindustrial Residues of Coffee, Sugarcane Straw and Coconut-Fibers in a Semi-pilot Plant for Production of Bio-oils: Gas Chromatographic Characterization

Pyrolysis of Agroindustrial Residues of Coffee, Sugarcane Straw and Coconut-Fibers in a Semi-pilot Plant for Production of Bio-oils: Gas Chromatographic Characterization

Isolation of polyphenols from spent coffee grounds and silverskin by mild hydrothermal pretreatment

ABSTRACTIn this study, a new method for isolation of polyphenols (PP) from spent coffee grounds (SCG) and coffee silverskin (CS) is described. The method consisted of a mild hydrothermal pretreatment at 120°C, for 20 min, using a liquid-to-solid ratio of 20 mL/g. PP (determined as gallic acid equivalents, GAE) were the most abundant components in the extracts produced by this method, corresponding to 32.92 mgGAE/gSCG and 19.17 mgGAE/gCS, among which flavonoids corresponded to 8.29 and 2.73 mg quercetin equivalents/g of SCG and CS, respectively. Both extracts presented antioxidant activity but the results were higher for SCG extract, probably due to the highest content of PP present. Negligible effects (less than 1% solubilization) were caused by the hydrothermal pretreatment on cellulose, hemicellulose, and protein fractions of these materials. Some mineral elements were present in the extracts, with potassium being the most abundant. Hydrothermal pretreatment under mild conditions was demonstrated to be an efficient method to recover antioxidant PP from coffee residues.

Characterization of coffee residues pellets and their performance in a residential combustor

ABSTRACTSpent coffee grounds (SCG) and coffee husks (CH) were evaluated as biofuels, after densification, for energy production. CH represent a specific problem for the coffee industry due to a low calorific value, high ash content, and a very low bulk density. Hence, the energetic potential of SCG (95 wt%)/CH (5 wt%) blend and pure SCG (100%) were examined. The blend of SCG and CH was limited to 5 wt% of CH because of the low bulk density of CH. Therefore, physicochemical and energetic characterizations of the produced pellets were performed. Thermogravimetric analyses were performed under nitrogen and air atmospheres to evaluate the CH behavior in the blend. Characterization study shows that both produced pellets could reach the French Agropellets standard (AQI). Thermal degradation showed that the mean reactivity of the SCG/HC pellets was higher than pure SCG. Then, combustion experiments were performed in a domestic combustor, after modification of the boiler power in order to improve its energetic performances. The presence of CH led to a rise of CO, NOx, VOC’s, and particle emissions. Nevertheless, the performances of the biofuels are almost in agreement the NF EN 12809 standard.

Effect of Extraction Methods on Chemical Composition, Angiotensin I-Converting Enzyme Inhibitory and Antioxidant Activity of Coffee Residue

In the present work, polysaccharides were extracted from coffee residue (CRP) using hot water and ultrasound-assisted extraction methods. Experimental results showed that both CRP had similar monosaccharide compositions (mannose and galactose), they presented also typical IR spectra characteristic of polysaccharides. CRP-U uronic acid content (6.28 ± 0.93%) was significantly (P < 0.05) higher than that of CRP-H (4.86 ± 0.07%). The ACE inhibitory activities (IC50 CRP-H = 0.2 mg/mL and IC50 CRP-U = 0.15 mg/mL) and antioxidant capacities of both CRP were assessed via different methods, including DPPH radical-scavenging activity assay (IC50 CRP-H = 0.08 mg/mL and IC50 CRP-U = 0.053 mg/mL), reducing power (RP0.5 CRP-H = 1.1 mg/mL and RP0.5 CRP-U = 0.8 mg/mL), and β-carotene bleaching inhibition assay (IC50 CRP-H = 4.65 mg/mL and IC50 CRP-U = 5.59 mg/mL). Those polysaccharides did not show any hemolytic activity towards erythrocytes. Practical Applications Coffee residue is the major coffee industry residue with an international generation of 6 million tons annually. Taking into account this huge quantity produced worldwide, the reutilization of this residue is a pertinent subject. Results indicated that coffee residue can be used to generate high value-added products, thus offering a valuable source of polysaccharides for application in wide range of biotechnological and functional food applications.

Oxidized Tapioca Starch As an Alginate Substitute for Encapsulation of Antioxidant from Coffee Residue

Abstract Coffee residue had polyphenol content 18.180 mg/g, yet its extract contained 1.746 mg/g polyhenol. Oxidized tapioca had comparable characteristics to alginate as an encapsulant material. Suspension concentration for encapsulation preparation was 5% (w/v) (encapsulant material/antioxidant extract). Microcapsul which is made by 25% oxidized tapioca starch had loading capacity 33.18%, capsul particle size 1699.3 μm, moisture content 10.57%, polyphenol content 1.23% (db) and antioxidant activity 29.04%. This capsul had better properties than control which is made without oxidized starch substitution.

EVALUATION OF THE COMBUSTION PROCESS OF COFFEE HUSK SAMPLES IN A DROP TUBE FURNACE (DTF)

Thermal conversion processes that use coffee husk are an alternative to solve the environmental problems of disposal and waste burning in open places and avoid greenhouse gases emissions. The present study evaluates in natura coffee husk samples and residues obtained from a combustion process in a Drop Tube Furnace (DTF). Such an evaluation consists in understanding the efficiency of the burning process, therefore the activation energies (Ea) of the combustion process for both samples were determined. The isoconversional kinetic method (Model Free Kinetics) was used for the determination of the Ea values of the samples. The Ea values of the main stages of the combustion process (devolatilization and carbonization) for both samples were compared. Thermogravimetric (TG) and Derivative Thermogravimetric (DTG) data at five heating rates (10, 15, 20, 25 and 30 oC min-1) were used for the determination of hemicellulose, cellulose and residual lignin. SEM (Scanning Electronic Microscopy) images and EDS (Energy Dispersive Spectroscopy) analysis were applied as complementary techniques in the combustion process. The results show that for both samples the Ea values were higher for the carbonization step than for devolatilization. The Ea values for the stages of devolatilization and carbonization for the residues were 33 and 15% lower than those for the in natura coffee husk samples. The lower Ea values in both steps for the residues are indicative of a reduction in the complexity of the reaction mechanism, which can be a parameter for the evaluation of the biomass combustion process. According to the SEM images, the residues showed exploded surfaces caused by the combustion process, whereas in the in natura samples a denser and robust structure was observed. The ash formed after the combustion process in the thermobalance was also evaluated by SEM and EDS analyses and showed a more homogenous structure with tiny particles in comparison with the in natura coffee husk samples. The EDS analysis confirmed the presence of precursor elements in the samples, such as potassium and other inorganic materials, which were intensified after the combustion process.

Overall adsorption rate of metronidazole, dimetridazole and diatrizoate on activated carbons prepared from coffee residues and almond shells

This study analyzed the overall adsorption rate of metronidazole, dimetridazole, and diatrizoate on activated carbons prepared from coffee residues and almond shells. It was also elucidated whether the overall adsorption rate was controlled by reaction on the adsorbent surface or by intraparticle diffusion. Experimental data of the pollutant concentration decay curves as a function of contact time were interpreted by kinetics (first- and second-order) and diffusion models, considering external mass transfer, surface and/or pore volume diffusion, and adsorption on an active site. The experimental data were better interpreted by a first-order than second-order kinetic model, and the first-order adsorption rate constant varied linearly with respect to the surface area and total pore volume of the adsorbents. According to the diffusion model, the overall adsorption rate is governed by intraparticle diffusion, and surface diffusion is the main mechanism controlling the intraparticle diffusion, representing >90% of total intraparticle diffusion.