Coffee By-products Research Articles

Coffea canephora silverskin from different geographical origins: A comparative study

Coffee silverskin is the major by-product of coffee roasting. Among all the coffee by-products, it is a relatively stable product due to its low moisture content. Currently, silverskin is used as direct fuel (e.g. firelighters), for composting and soil fertilization. As it is a natural source of several bioactive compounds that can be extracted and further used for food or dermocosmetic purposes, the valorization of this by-product is of utmost importance, having in view the sustainability and circular economy principles.The aim of this work was to evaluate, for the first time, the influence of different geographical origins (Brazil, Uganda, Vietnam, Cameroon, Indonesia, and India) on the chemical composition of silverskin obtained from Coffea canephora beans.Different parameters were analysed, including ashes, protein, soluble and insoluble fiber, and total lipid amounts; vitamin E, fatty acid and phenolics profiles (by HPLC-DAD-FLD, GC-FID, and HPLC-DAD, respectively); caffeine, 5‑caffeoylquinic acid and hydroxymethyfurfural contents (by HPLC-DAD); and antioxidant profile (total phenolics and flavonoids contents, DPPH inhibition, and Ferric Reducing Antioxidant Power).Significant differences (p < 0.05) were found between the samples, especially regarding the fatty acid profile and the antioxidant composition. For instance, the Brazilian silverskin was the richest in total lipids and vitamin E, while the Indian silverskin was the poorest in phenolics and antioxidant activity, and presented a higher relative percentage of saturated fatty acids. A Principal Component Analysis allowed to group the studied samples according to their geographical proximity.

Title “Organic Fertilizers” in Vietnam’s Markets: Nutrient Composition and Efficacy of Their Application

Organic fertilizers have recently been gaining popularity; however, their governance is not completely assessed in developing countries. This study investigated the nutrient composition of so-called organic fertilizers in Vietnam’s markets and issues related to their production, and evaluated their potential to contaminate the groundwater. We analyzed the physicochemical properties of 12 domestic and four imported products of the fertilizers, and conducted a cultivation experiment in sandy soil with the fertilizer applied at a rate of 200 mg N kg−1 soil using an automatic watering apparatus in a greenhouse. We further studied the production of an “organic fertilizer” from coffee by-products. The nutrient content greatly varied among domestic products, whereas they were quite similar among imported products. The product packaging of the collected samples lacked information regarding raw materials. Two thirds of the domestic products contained over 30% of the total N in the inorganic form, implying that the N content dramatically increased in the fertilizers rather than in their supposed raw materials. The stages involved in the production were composting, the addition of extra soil as a bulking agent, and the mixing-in of chemical substances to increase the nutrient content before packing. The remarkably high ratio of inorganic N to total N was attributed to excessive N leaching from soil by the application of domestic fertilizers. These results suggested the need for quality criteria guidelines for organic fertilizers in Vietnam that underline not only nutrient levels, but also the control of raw materials and production process of compost, because they are closely related to nutrient uptake and the leaching loss of nutrients.

Validation of coffee by-products as novel food ingredients

Abstract This research aimed to validate coffee husk, parchment and silverskin as new health-promoting food ingredients. Characterization of the novel ingredients was carried out by Raman and infrared spectroscopy and analysis of total phenolic compounds, chlorogenic acid, caffeine and dietary fiber. Antioxidant properties of the novel ingredients were tested by ABTS and intracellular ROS formation in HepG2 cells. Pesticides, mycotoxins, acrylamide and acute toxicity experiments following OECD Test Guidelines 425 were performed to assess the food safety of extracts, solid residues and raw materials. Husk and silverskin are proposed as a source of two food ingredients: aqueous extracts enriched in phytochemicals and antioxidant dietary fiber while parchment is proposed as a natural source of antioxidant dietary fiber. No lesions were found in selected isolated vital organs from treated animals. Coffee by-products can be converted into safe food ingredients allowing a whole food waste recovery. Analyses of contaminants are essential for achieving this goal.

Valorization of coffee byproducts for bioethanol production using lignocellulosic yeast fermentation and pervaporation

Industrial residue management is a critical element of sustainable development. The aim of this research was to investigate the potential of different coffee waste fractions for bioethanol fermentation and its purification by pervaporation; these fractions and the role of pervaporation in this application have not been studied before. Bioethanol production from different coffee waste fractions has now been studied by acid or acid and enzymatic hydrolysis. The fermentation was conducted using two different yeasts (baker’s yeast and lignocellulosic yeast). By using the cellulolytic enzymes and lignocellulosic yeast, a higher bioethanol yield was achieved. Further purification of the fermented filtrate was carried out by an alcohol selective pervaporation membrane at four temperatures (23, 30, 40 and 50 °C). Hydrolysis of the samples using cellulose complex and β-glucosidase enzymes and fermentation with lignocellulosic yeast, followed by purification using pervaporation resulted a superior bioethanol yield of 51.7 ± 7.4 g/l for spent coffee and 132.2 ± 40 g/l for husk. Husk hydrolysis using cellulolytic enzymes and fermentation with lignocellulosic yeast, followed by product recovery through pervaporation membrane, was found to be the optimal procedure, producing ethanol at a concentration of 132.2 ± 40 g/l. In general, husk hydrolysis using acid and cellulolytic hydrolysis and fermentation with lignocellulosic yeast GSE16-T18 followed by pervaporation was found to be the best process for producing the highest ethanol yield compared to the other fractions of coffee waste samples.

Mathematical models applied to the optimisation of mixtures in the production of silage from coffee by-products

The aim of this work was to propose a mathematical model to determine the best combination of the by-products of coffee processing in the production of silage. To this end, 13 treatments were evaluated, resulting from the combination of wet coffee husks (WCH) and dried coffee husks (DCH), both with and without the use of molasses (M) and with or without the use of the inoculant Lactobacillus plantarum (I). From these components, various mixtures were proposed and evaluated, using the technique of simultaneous optimisation of multiple response variables. Silages with the best characteristics were obtained from the use of 76.40% WCH, 18.77% DCH, 4.83% of M and 0.0001% I.

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.

커피와 커피박 침출주의 항산화 활성 및 주요 생리활성 물질의 비교 분석

Sensory evaluation, in vitro antioxidant activities and main compounds of coffee water-extract, coffee liqueur (CL) and coffee-ground liqueur (CGL) were investigated to consider their industrialization. Sensory evaluation showed that all groups of CGL without 25% CGL (3 month) were relatively higher than CL groups. Total phenolic compounds and in vitro antioxidant activities such as 1,1-diphenyl-2picryl-hydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP) were also performed. The group of 35% CGL had higher total phenolic compounds than others, and the result of DPPH radical scavenging activity was similar to that of total phenolic compounds. In addition, 35% CGL is comparable to the FRAP of coffee water extract (CE). Qualitative and quantitative analysis using high-performance liquid chromatography (HPLC) were performed, and chlorogenic acid as a ployphenolic compound and caffeine as a nonpolyphenolic compound were detected in all samples. Moreover, the HPLC analysis showed that CGLs contain a larger amounts of chlorogenic acid (difference of 0.3~10.5%) and also greater amounts of caffeine (difference of 10.0~18.2%) more then CE. Consequently, these results suggest that coffee-ground as coffee by-products could be used as commercially available food substances because of its physiological molecules remained.

Free tocopherols as chemical markers for Arabica coffee adulteration with maize and coffee by-products

Coffee adulteration with coffee by-products is increasing, due mostly to its chemical and sensorial similarity with ground roasted coffee. Based on the recognized effectiveness of tocopherols as markers for coffee adulteration with maize, we have further explored their ability to distinguish adulterations with coffee husks, the main residue of coffee dry processing. For the purpose, a ground roasted arabica coffee sample was adulterated with 5–50% (w/w) of roasted husks, cleaned roasted husks (without the inner parchment layer), and roasted maize. Extracted lipids were analysed by normal-phase HPLC, with florescence detection, and the tocopherol amounts analysed by mean tests, regression analysis, PCA, LDA and SIMCA. γ–tocopherol, detected in residual amounts in roasted coffee, was inversely proportional to coffee purity, being the compound that better contributed for adulteration detection, independently of the adulterant tested. Coffee richness in β–tocopherol, in opposition to all the adulterants tested, also contributes for this discrimination. Based on the tocopherol profiles, adulterations can be perceived at the lowest amounts tested (5%), but higher amounts are necessary for identification of the adulterant, namely ≥10% for maize and from 20% upwards for coffee by-products. For heavy adulterations is even possible to distinguish between husks and cleaned husks. This method is simple to implement in food analysis laboratories, with applicability for adulteration screening or to complement other instrumental methods.

Coffee Silverskin Extract Protects against Accelerated Aging Caused by Oxidative Agents.

Nowadays, coffee beans are almost exclusively used for the preparation of the beverage. The sustainability of coffee production can be achieved introducing new applications for the valorization of coffee by-products. Coffee silverskin is the by-product generated during roasting, and because of its powerful antioxidant capacity, coffee silverskin aqueous extract (CSE) may be used for other applications, such as antiaging cosmetics and dermaceutics. This study aims to contribute to the coffee sector’s sustainability through the application of CSE to preserve skin health. Preclinical data regarding the antiaging properties of CSE employing human keratinocytes and Caenorhabditis elegans are collected during the present study. Accelerated aging was induced by tert-butyl hydroperoxide (t-BOOH) in HaCaT cells and by ultraviolet radiation C (UVC) in C. elegans. Results suggest that the tested concentrations of coffee extracts were not cytotoxic, and CSE 1 mg/mL gave resistance to skin cells when oxidative damage was induced by t-BOOH. On the other hand, nematodes treated with CSE (1 mg/mL) showed a significant increased longevity compared to those cultured on a standard diet. In conclusion, our results support the antiaging properties of the CSE and its great potential for improving skin health due to its antioxidant character associated with phenols among other bioactive compounds present in the botanical material.

Use of Coffee Silverskin and Stevia to Improve the Formulation of Biscuits

1. Embracing nutritional qualities, biological activities and technological properties of coffee byproducts in functional food formulation Feyera Gemechu Trends in Food Science & Technology CrossRef

Revalorization of coffee by-products. Prebiotic, antimicrobial and antioxidant properties

Coffee industries are a key sector in the global economy due to income reporting and job creation. Coffee companies produce annually more than 2 billion tons of by-products such as coffee spent grounds (CSG) and coffee silverskin (CS). And most of which are thrown away and are not recycled for other purposes. Here we show the prebiotic, antimicrobial and antioxidant capacity of CSG and CS, as well as those melanoidins (a coffee component generated during the roasting process) obtained from the former. The prebiotic activity was important in both CSG and CS, although the presence of coffee melanoidins (CM) interfered with such beneficial properties. On the contrary, CM exerted an intense antimicrobial activity that could be used to avoid the growth of pathogenic bacteria in food products. In addition, CSG, CS and CM were highly antioxidant, even their indigestible fraction, which were the most relevant. Finally, we found that the addition of sugar during coffee roasting, namely torrefacto, increased the antioxidant and antimicrobial activity due to a larger generation of CM, although prebiotic activity was not affected. Therefore, CSG, CS and CM should be recycled in order to be used as a source of new food ingredients.

Biodegradation of coffee pulp tannin by Penicillium verrucosum for production of tannase, statistical optimization and its application

Coffee pulp is a primary by-product produced during coffee processing and represents 30% of the coffee fruit on a dry-weight basis. A novel potential tannin degrading fungi was isolated from coffee by-products. Among the various fungi isolated, Penicillium sp. CFR303 was found to be potent with 66.5±0.9% tannin degradation. The potent tannin degrader was identified as Penicillium verrucosum using internal transcribed spacer's (ITS) −5.8S rDNA analysis. Solid state fermentation was carried out on coffee pulp as a sole carbon source and yielded 28.173±1.4U/gds of tannase. Further, 3.93 fold increase in tannase production (115.995U/gds) was achieved using central composite rotatable design, a statistical approach. Model validations showed excellent agreement between the experimental results and the predicted responses with a confidence level of 95%. Coffee pulp accounts to 8–10% tannin content and the present study demonstrates coffee pulp as an excellent substrate for production of value added products. Aonla and pomegranate juice were treated with partially purified tannase and the degradation of tannins was evident by changes in the physicochemical parameters of the juice. Thus, the present investigation signifies utilization of coffee pulp for production of tannase as value addition and its potential application in the food industry.

Agro-residues as Alternative for Xylanase Production by Filamentous Fungi

Agro-industrial wastes are the most abundant renewable resource on earth and are available in large quantities. However, the disposal of these wastes presents an increasing environmental problem. Recently, there has been a great interest in the exploitation of these wastes as low-cost raw materials for the production of value-added compounds as microbial enzymes by submerged or solid-state fermentation systems. This review focuses on alternatives for xylanase production using agro-residues as substrates. In recent years, the interest in xylanase, which plays an important role in the breakdown of xylan, has markedly increased due to its wide variety of biotechnological applications. Among several agro-industrial residues that have been intensively investigated, many, such as wheat bran, wheat straw, and sugarcane bagasse, are suitable and result in high yields of xylanase, leading to low production costs. In addition, many relatively unexplored residues, such as oil palm wastes, sorghum straw, and coffee by-products, are some of the most promising substrates for xylanase production, requiring further assessment.

Agro-residues as Alternative for Xylanase Production by Filamentous Fungi

Agro-industrial wastes are the most abundant renewable resource on earth and are available in large quantities. However, the disposal of these wastes presents an increasing environmental problem. Recently, there has been a great interest in the exploitation of these wastes as low-cost raw materials for the production of value-added compounds as microbial enzymes by submerged or solid-state fermentation systems. This review focuses on alternatives for xylanase production using agro-residues as substrates. In recent years, the interest in xylanase, which plays an important role in the breakdown of xylan, has markedly increased due to its wide variety of biotechnological applications. Among several agro-industrial residues that have been intensively investigated, many, such as wheat bran, wheat straw, and sugarcane bagasse, are suitable and result in high yields of xylanase, leading to low production costs. In addition, many relatively unexplored residues, such as oil palm wastes, sorghum straw, and coffee by-products, are some of the most promising substrates for xylanase production, requiring further assessment.

STATISTICAL OPTIMIZATION OF BIOPROCESS PARAMETERS FOR ENHANCED GALLIC ACID PRODUCTION FROM COFFEE PULP TANNINS BY Penicillium verrucosum

Gallic acid (3,4,5-trihydroxybenzoic acid) was produced by microbial biotransformation of coffee pulp tannins by Penicillium verrucosum. Gallic acid production was optimized using response surface methodology (RSM) based on central composite rotatable design. Process parameters such as pH, moisture, and fermentation period were considered for optimization. Among the various fungi isolated from coffee by-products, Penicillium verrucosum produced 35.23 µg/g of gallic acid on coffee pulp as sole carbon source in solid-state fermentation. The optimum values of the parameters obtained from the RSM were pH 3.32, moisture 58.40%, and fermentation period of 96 hr. Gallic acid production with an increase of 4.6-fold was achieved upon optimization of the process parameters. The results optimized could be translated to 1-kg tray fermentation. High-performance liquid chromatography (HPLC) analysis and spectral studies such as mass spectroscopy (MS) and 1H-nuclear magnetic resonance (NMR) confirmed that the bioactive compound isolated was gallic acid. Thus, coffee pulp, which is available in enormous quantity, could be used for the production of value-added products that can find avenues in food, pharmaceutical, and chemical industries.

Determination of the Elemental Composition of Coffee Using Instrumental Methods

Although the content of elements in coffee is only about 5 % (m/m), it seems to be a good indicator of the coffee authenticity. Apparently, it can bring the useful information about individual elemental patterns that are distinctive to the origin of growing soils for coffee plants in addition to cultivation and environmental conditions used. The elemental analysis of coffee by means of instrumental measurement methods may have other uses. It can be used to prove the high quality and safety of raw coffee beans, various coffee byproducts, and the final coffee product in the market. Commonly, different atomic absorption and emission spectrometry and instrumental neutron activation analysis methods are used to determine concentrations of various elements in green, roasted, and ground or instant coffees and coffee infusions, but these samples have to be suitably prepared prior to the analysis.

Evaluation of Composting Process and Quality of Compost from Coffee By-Products (Coffee Husk &amp; Pulp)

Coffee pulp and husk are the main by-products generated by the coffee processing station and are disposed into arable land and surface water. Due to the contribution of these by-products to environmental pollution, environmentally friendly disposal methods are necessary. Therefore, composting as environmental friendly option for utilization of coffee by-products is important. The objectives of the study were to assess the properties of coffee by-products compost and analyzing changes in physico-chemical properties during process of composting. To this end, (coffee husk + pulp) (control), (coffee husk + pulp + cow dung), (coffee husk + pulp + Millettia ferruginea), (coffee husk + pulp + cow dung + Millettia ferruginea), (coffee husk + pulp + effective microorganism) were used to prepare compost. The experiment was laid in RCBD (5x3). The physico-chemical parameters were determined for all the treatments at 25, 45 and 70 days of composting. The level of pH in coffee by-products compost amended with Millettia ferruginea were highly significant (P&lt;0.0001) as compared to coffee by-products compost amended with cow dung and effective microorganism alone. The level of N and Exch. K in coffee by-products compost amended with cow dung and Millettia ferruginea were highly significant (P&lt;0.0001) as compared to the control and coffee by-products compost amended with cow dung and effective microorganism alone. The level of total N, OM, and C/N ratio in 25 day of composting were highly significant (p&lt;0.0001) as compared to 70 day of composting. The physico-chemical parameter in different time of composting indicates that, composting coffee by-products compost up to 70 day were important to acquire quality compost. Comparison of experimental results proved that coffee byproducts compost amended with Millettia ferruginea and cow dung was better than other treatments for quality compost preparation. It is better to amend the coffee by-products with organic material before composting to improve the quality of the compost.Key words: Coffee by products, Composting, Quality compost

Functional properties of coffee and coffee by-products

Coffee, one of the most popular beverages, is consumed by millions of people every day. Traditionally, coffee beneficial effects have been attributed solely to its most intriguing and investigated ingredient, caffeine, but it is now known that other compounds also contribute to the valuable properties of this beverage. The role of coffee brew consumption in preventing some severe and prevalent diseases justifies its classification as a functional beverage. These properties are determined directly by the composition of the green beans and the changes that occur during roasting. On the other hand, by-products of coffee fruit and bean processing can also be considered as potential functional ingredients for the food industry. The coffee husks, peel and pulp, which comprises nearly 45% of the cherry, are one of the main by-products of coffee agro-industry and might be a valuable material for several purposes, including extraction of caffeine and polyphenols. Other by-products of coffee processing have been less studied, such as the mucilage and the parchment; however, they might have a high potential as a source of important ingredients as well. Furthermore, the use of the roasted coffee silverskin as a dietary fiber rich ingredient and for its antioxidative properties has also been evaluated. Finally, spent beans have been studied mainly for their antioxidative properties. The aim of this paper is to compile recent information on the functional properties of coffee, coffee beans and by-products in terms of the associated potential health benefits. The data in this review have been organized in sections according to the coffee product or by-product.

Recovery of Phenolic Antioxidants and Functional Compounds from Coffee Industry By-Products

The recovery process of the phenolic compounds from the coffee industry by-products and their antioxidant activity were investigated in this work. The coffee by-products (coffee pulp, husk, silver skin, and spent coffee) were obtained from coffee processing industry. The phenolic conserves were extracted using solvent mixture of isoproponal and water. The yield of the conserve was highest in case of silver skin (25%) followed by spent waste (19%) and cherry husk (17%) when pretreated with viscozyme. The conserve enclosed chlorogenic acid as major component when analyzed with high-performance liquid chromatography. The bioactive conserves prepared from coffee by-products possessed 65%–70% antioxidant activity. Apart from these, the coffee by-products encompassed total dietary fiber of 40%–80%. Whereas the soluble and insoluble fiber proportion of the coffee by-product ranged between 16–35% and 18–64%, respectively. The antioxidant activity of coffee by-product fiber ranged from 1.5 to 2.0 mmol trolox/100 g and is analogous to that of widespread fruits and fresh vegetables. The hydration properties such as water holding capacity of each by-product was strictly related to the amount of insoluble fiber and to the granulometry. This is the first report on the isolation of bioactive and functional compounds from coffee by-products and can be a source of new value-added products such as phenolic antioxidant adjunct for food processing.

Windrow composting of sugarcane and coffee byproducts

Compost produced from lignocellulosic agricultural residues is found to be suitable for maintaining soil properties and health. Results of experimental trials of large scale windrow composting of sugarcane press mud, cane bagasse and coffee pulp mixtures are presented and discussed. Filter press mud and bagasse mixtures were transformed into composted products in 120 days, of which 80 days were of active material machine turning in the windrows. However, the mixtures containing coffee pulp were active for a much longer time period as the Solvita® readings showed. Bagasse was an important component of the mixture as it provided an adequate structure in the heap. The compost product containing 50 % coffee pulp at the start caused adverse effects on black bean seed germination and decreased the growth of black beans and tomato when mixed with soil above 2.5 and 5 %, respectively. These effects were not observed with the products containing sugarcane press mud and bagasse only.