Coffee and Coffee Byproducts: Processing, Quality, Nutritional and Health Aspects

A special issue of Foods (ISSN 2304-8158). This special issue belongs to the section "Drinks and Liquid Nutrition".

Deadline for manuscript submissions: closed (31 March 2023) | Viewed by 27576

Special Issue Editors

PPGCA, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte 31270-901, MG, Brazil
Interests: coffee; agricultural wastes; valorization of byproducts; spectroscopic methods
Special Issues, Collections and Topics in MDPI journals
PPGCA, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG 31270-901, Brazil
Interests: coffee; agri-food wastes; valorization of byproducts; biofuels
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Coffee is one of the most popular beverages worldwide and a rather relevant food commodity from an economic standpoint. In the coffee processing chain, a series of byproducts or wastes are generated, including coffee husks and pulp, parchment, chaff (silverskin), and spent coffee grounds. Currently, the majority of these byproducts are being used in low-value applications such as compost, ingredients for animal feed, or fodder for in-farm or coffee-industry-in-house combustion systems. Regardless, these byproducts are rich in a diversity of chemical components and are thus suitable for a wide variety of new exploitation pathways.

Coffee phenolics have attracted much interest in recent years due to their strong antioxidant and metal-chelating properties and are thus believed to provide protection against free radical damage and reduce the risk of degenerative diseases associated with oxidative stress. These compounds are not only available in coffee but also in the corresponding processing byproducts, and these can also be viewed as alternative sources of dietary fibers. Among the promising but still relatively unexplored applications of coffee byproducts, their direct application or use as raw materials for the recovery of functional compounds of potential interest to the food industry is an interesting possibility.

This Special Issue invites research to characterize bioactive compounds in coffee and its byproducts and to explore their potential applications for the food industry. Papers may focus on the development of novel methods for coffee analysis, either identifying specific bioactive components or determining their effect on the resulting antioxidant properties. Other interesting aspects include the effect of novel processing or extraction techniques on byproducts’ composition; assessment of the health-promoting properties of bioactive compounds found in coffee and its byproducts, including studies of bioavailability, bioaccessibility, and mechanisms of action; and the application of coffee byproducts or extracted substances directly on food or related products (active packaging, etc.). Submissions may either provide a review of the scientific literature or describe original research.

Prof. Dr. Adriana Franca
Prof. Dr. Leandro S. Oliveira
Guest Editors

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Keywords

  • byproduct valorization
  • coffee
  • coffee byproducts
  • coffee waste recovery
  • bioactive compounds
  • nutraceutical value

Published Papers (8 papers)

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Research

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16 pages, 3646 KiB  
Article
Structural Characteristics, Rheological Properties, and Antioxidant and Anti-Glycosylation Activities of Pectin Polysaccharides from Arabica Coffee Husks
by Zelin Li, Bin Zhou, Tingting Zheng, Chunyan Zhao, Yan Gao, Wenjun Wu, Yingrun Fan, Xuefeng Wang, Minghua Qiu and Jiangping Fan
Foods 2023, 12(2), 423; https://0-doi-org.brum.beds.ac.uk/10.3390/foods12020423 - 16 Jan 2023
Cited by 6 | Viewed by 2055
Abstract
As primary coffee by-products, Arabica coffee husks are largely discarded during coffee-drying, posing a serious environmental threat. However, coffee husks could be used as potential material for extracting pectin polysaccharides, with high bioactivities and excellent processing properties. Thus, the present study aimed to [...] Read more.
As primary coffee by-products, Arabica coffee husks are largely discarded during coffee-drying, posing a serious environmental threat. However, coffee husks could be used as potential material for extracting pectin polysaccharides, with high bioactivities and excellent processing properties. Thus, the present study aimed to extract the pectin polysaccharide from Arabica coffee husk(s) (CHP). The CHP yield was calculated after vacuum freeze-drying, and its average molecular weight (Mw) was detected by gel permeation chromatography (GPC). The structural characteristics of CHP were determined by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), proton nuclear magnetic resonance (1H NMR), and scanning electron microscopy (SEM). Additionally, the rheological and antioxidant properties of CHP and the inhibition capacities of advanced glycation end products (AGEs) with different concentrations were evaluated. The interaction mechanisms between galacturonic acid (GalA) and the AGE receptor were analyzed using molecular docking. The results demonstrated that the CHP yield was 19.13 ± 0.85%, and its Mw was 1.04 × 106 Da. The results of the structural characteristics results revealed that CHP was an amorphous and low-methoxyl pectic polysaccharide linked with an α-(1→6) glycosidic bond, and mainly composed of rhamnose (Rha, 2.55%), galacturonic acid (GalA, 45.01%), β-N-acetyl glucosamine (GlcNAc, 5.17%), glucose (Glc, 32.29%), galactose (Gal, 6.80%), xylose (Xyl, 0.76%), and arabinose (Ara, 7.42%). The surface microstructure of CHP was rough with cracks, and its aqueous belonged to non-Newtonian fluid with a higher elastic modulus (G′). Furthermore, the results of the antioxidant properties indicated that CHP possessed vigorous antioxidant activities in a dose manner, and the inhibition capacities of AGEs reached their highest of 66.0 ± 0.35% at 1.5 mg/mL of CHP. The molecular docking prediction demonstrated that GalA had a good affinity toward AGE receptors by −6.20 kcal/mol of binding energy. Overall, the study results provide a theoretical basis for broadening the application of CHP in the food industry. Full article
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9 pages, 1826 KiB  
Communication
Coffee Consumption during the COVID Pandemic in a Portuguese Sample: An Online Exploratory Study
by Patrícia Batista, Anabela Afonso, Maria João Monteiro, Manuela Pintado and Patrícia Oliveira-Silva
Foods 2023, 12(2), 421; https://0-doi-org.brum.beds.ac.uk/10.3390/foods12020421 - 16 Jan 2023
Viewed by 2248
Abstract
Background: Coffee is one of the most consumed beverages worldwide and is part of the Portuguese lifestyles. This study aims to describe coffee consumption during the COVID-19 pandemic, the change in consumption, the relation between work and familiar pressure during the COVID-19 pandemic [...] Read more.
Background: Coffee is one of the most consumed beverages worldwide and is part of the Portuguese lifestyles. This study aims to describe coffee consumption during the COVID-19 pandemic, the change in consumption, the relation between work and familiar pressure during the COVID-19 pandemic and coffee consumption, and the reasons for this consumption pattern. Methods: This is a cross-sectional study conducted by an online questionnaire (n = 463) between March and June 2020. During the data collection phase, information about coffee consumption and socio-demographic characteristics were gathered. Results: All respondents were and are coffee consumers. The coffee average intake before the COVID-19 pandemic was 2.40 ± 0.84 cups of coffee per day, and the average consumption during the COVID-19 confinement was 2.68 ± 0.88 cups. Consumption increased during the COVID-19 pandemic, but a correlation between the consumption changes and the familiar or work pressure was not found. The general reasons for the increase in the coffee consumption were “social/cultural” (27%), “the search for energy “boost”” (22.9%), “to feel awake” (22.7%), “to deal with stress” (22.7%) and “the taste” (21.8%). Conclusions: The results suggest the ever-increasing popularity of coffee consumption. Respondents also highlighted that some situations make them more prone to consume coffee consumption, such as when they face stress and the need to control tiredness. The COVID pandemic depleted a change in behaviors. Full article
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13 pages, 847 KiB  
Article
A New HPLC-MS/MS Method for the Simultaneous Determination of Quercetin and Its Derivatives in Green Coffee Beans
by Ahmed M. Mustafa, Doaa Abouelenein, Simone Angeloni, Filippo Maggi, Luciano Navarini, Gianni Sagratini, Agnese Santanatoglia, Elisabetta Torregiani, Sauro Vittori and Giovanni Caprioli
Foods 2022, 11(19), 3033; https://0-doi-org.brum.beds.ac.uk/10.3390/foods11193033 - 30 Sep 2022
Cited by 13 | Viewed by 2466
Abstract
Green coffee (Coffee arabica and Coffee robusta) is one of the most commonly traded goods globally. Their beans are enriched with polyphenols and numerous health benefits are associated with their consumption. The main aim of this work was to develop a [...] Read more.
Green coffee (Coffee arabica and Coffee robusta) is one of the most commonly traded goods globally. Their beans are enriched with polyphenols and numerous health benefits are associated with their consumption. The main aim of this work was to develop a new and fast analytical HPLC-MS/MS method to simultaneously determine six flavonoid polyphenolic compounds (quercetin, rutin, isorhamnetin, quercetin-3-glucouronide, hyperoside, and quercitrin) in 22 green coffee samples from six different geographical origins (Ethiopia, Brazil, Guatemala, Nicaragua, India and Colombia). In addition, by adjusting pH, temperature, solvent type, and extraction duration, several extraction methods such as acidic and alkaline hydrolysis, and extraction without hydrolysis were evaluated. The optimal extraction procedure in terms of recovery percentages (78.67–94.09%)was acidic hydrolysis at pH 2, extraction temperature of 60 °C, extraction solvent of 70% ethanol, and extraction duration of 1.5 h. Hyperoside (878–75 μg/kg) was the most abundant compound followed by quercitrin (408–38 μg/kg), quercetin (300–36 μg/kg), rutin (238–21 μg/kg), and quercetin-3-glucouronide (225–7 μg/kg), while isorhamnetin (34–3 μg/kg) showed the lowest amount. Overall, green coffee beans are rich in flavonoid polyphenolic compounds and could be used as part of a healthy diet. Full article
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19 pages, 1277 KiB  
Article
Effect of Coffee on the Bioavailability of Sterols
by Cristiana L. Pires, Inês M. V. Silva, Manuel A. Coimbra, Maria João Moreno and Filipe Coreta-Gomes
Foods 2022, 11(19), 2935; https://0-doi-org.brum.beds.ac.uk/10.3390/foods11192935 - 20 Sep 2022
Cited by 2 | Viewed by 1473
Abstract
Absorption at the intestinal epithelium is a major determinant of cholesterol levels in the organism, influencing the entry of dietary cholesterol and the excretion of endogenous cholesterol. Several strategies are currently being followed to reduce cholesterol absorption, using both pharmacological agents or food [...] Read more.
Absorption at the intestinal epithelium is a major determinant of cholesterol levels in the organism, influencing the entry of dietary cholesterol and the excretion of endogenous cholesterol. Several strategies are currently being followed to reduce cholesterol absorption, using both pharmacological agents or food ingredients with hypocholesterolemic properties. Coffee has recently been shown to affect cholesterol bioaccessibility, although it has not been shown if this translates into a decrease on cholesterol bioavailability. In this work, coffee obtained with different commercial roasting (light and dark) and grinding (finer and coarser) was evaluated regarding their effect on cholesterol absorption through Caco-2 monolayers, mimicking the intestinal epithelium. The fluorescent dehydroergosterol was used as a sterol model, which was shown to permeate Caco-2 monolayers with a low-to-moderate permeability coefficient depending on its concentration. In the presence of coffee extracts, a 50% decrease of the sterol permeability coefficient was observed, showing their potential to affect sterol bioavailability. This was attributed to an increased sterol precipitation and its deposition on the apical epithelial surface. A higher hypocholesterolemic effect was observed for the dark roasting and finer grinding, showing that the modulation of these technological processing parameters may produce coffees with optimized hypocholesterolemic activity. Full article
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13 pages, 942 KiB  
Article
Hazard Ratio and Hazard Index as Preliminary Estimators Associated to the Presence of Furans and Alkylfurans in Belgian Foodstuffs
by Zouheir Alsafra, Georges Scholl, Bruno De Meulenaer, Gauthier Eppe and Claude Saegerman
Foods 2022, 11(16), 2453; https://0-doi-org.brum.beds.ac.uk/10.3390/foods11162453 - 14 Aug 2022
Cited by 4 | Viewed by 1568
Abstract
This paper provides an estimation of the hazard related to the presence of furan and five alkyl furans (2- and 3-methylfuran, 2-ethylfuran, 2,5- and 2,3-dimethylfuran) in foodstuffs available in the Belgian market. To achieve this objective, a specific sampling plan was designed to [...] Read more.
This paper provides an estimation of the hazard related to the presence of furan and five alkyl furans (2- and 3-methylfuran, 2-ethylfuran, 2,5- and 2,3-dimethylfuran) in foodstuffs available in the Belgian market. To achieve this objective, a specific sampling plan was designed to ensure that the samples collected (n = 1003) represent the diversity of the Belgian food chain. Herein, the concepts of the Hazard Ratio of a sample (HRs) and the Hazard Index of a sample (HIs) were introduced to primarily characterize the hazard related to the co-occurrence of these compounds. The HRs was measured as the ratio of the potential daily exposure to a substance (expressed in mg/Kg of food) to both the 10% reference dose level for chronic effects (expressed in mg/(kg b.w*day)) and the human standard weight (expressed in kg). Whereas the HIs is the sum of the HRs of compounds that affect the same target organ/system, a hazard index greater than one indicates a highly contaminated matrix that could induce a hazard. It is an alarm indicating that additional attention should be given to this matrix. This may involve additional analyses to confirm the high level, to identify sources, etc. It is also an alarm for the risk assessor to be very careful with flagged matrices and to avoid combination with other matrices. The HIs highlight a relatively low concern for all foods analyzed (HI median < 1.0) with a relatively higher suspected hazard for coffee drinks (HI median = 0.068, HI max = 0.57). This preliminary estimation of the potential hazard suggests that coffee beverages should be examined in more detail in a full risk assessment and that coffee consumption should be taken with caution given the levels of furan and alkylfurans reported in this study. Full article
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16 pages, 341 KiB  
Article
Regular Consumption of Green Coffee Phenol, Oat β-Glucan and Green Coffee Phenol/Oat β-Glucan Supplements Does Not Change Body Composition in Subjects with Overweight and Obesity
by Joaquín García-Cordero, José Luis Sierra-Cinos, Miguel A. Seguido, Susana González-Rámila, Raquel Mateos, Laura Bravo-Clemente and Beatriz Sarriá
Foods 2022, 11(5), 679; https://0-doi-org.brum.beds.ac.uk/10.3390/foods11050679 - 25 Feb 2022
Cited by 3 | Viewed by 2918
Abstract
Many in vitro and in vivo studies support that green coffee polyphenols (GCP) and beta-glucans (BG) present important hypolipidaemic and hypoglycaemic effects. However, their weight-management/-reducing properties are less clear. Considering that these compounds act on different metabolic pathways, their combination could increase their [...] Read more.
Many in vitro and in vivo studies support that green coffee polyphenols (GCP) and beta-glucans (BG) present important hypolipidaemic and hypoglycaemic effects. However, their weight-management/-reducing properties are less clear. Considering that these compounds act on different metabolic pathways, their combination could increase their beneficial health effects. The aim of the present study was to investigate the effects of regularly consuming supplements containing GCP, BG or the novel GCP/BG combination on body composition in overweight/obese subjects without changing their dietary and physical activity habits, hence addressing the difficulty to adapt to lifestyle changes. A randomised, cross-over, blind trial was carried out in 29 volunteers who consumed GCP (300 mg), BG (2.5 g) or GCP/BG (300 mg + 2.5 g) twice a day for 8 weeks. At the beginning and end of each of the interventions, body weight, body mass index, body fat%, intracellular and extracellular water, skinfolds (tricipital, bicipital, subscapularis, suprailiac, leg and thigh) and body circumferences (waist, hip, thigh, calf, branchial) were measured. Along the study, volunteers filled out 72 h dietary records, and physical activity was measured using accelerometers. The results show that dietary intake and physical activity were unchanged throughout the study; however, there were no changes in any of the body composition parameters analysed with any of the food supplements. In conclusion, the regular intake of GCP, BG and GCP/BG, without changes in diet and physical activity, is not an efficient strategy to lose weight or induce other positive changes in body composition, although results should be taken with caution as the study was underpowered. Full article
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20 pages, 9848 KiB  
Article
Evaluation of Techniques for Intensifying the Process of the Alcoholic Extraction of Coffee Ground Oil Using Ultrasound and a Pressurized Solvent
by Tatiane Akemi Toda, Ana Julia Morelli Santana, Julieta Adriana Ferreira, Eliria Maria de Jesus Agnolon Pallone, Claudio Lima de Aguiar and Christianne Elisabete da Costa Rodrigues
Foods 2022, 11(4), 584; https://0-doi-org.brum.beds.ac.uk/10.3390/foods11040584 - 17 Feb 2022
Cited by 4 | Viewed by 2006
Abstract
Ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) techniques were evaluated and compared with conventional extraction for obtaining spent coffee ground oil (SCGO). The use of absolute ethanol (ET0) and hydrated ethanol (ET6) as solvents, two levels of SCG mass ratio:solvent, 1:4 (U4) [...] Read more.
Ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) techniques were evaluated and compared with conventional extraction for obtaining spent coffee ground oil (SCGO). The use of absolute ethanol (ET0) and hydrated ethanol (ET6) as solvents, two levels of SCG mass ratio:solvent, 1:4 (U4) and 1:15 (U15), and ultrasound powers of 0, 200, 400, and 600 W were tested. ET0 and U15 resulted in higher extraction yields of SCGO (YSCGO, 82%). A positive effect of sonication on YSCGO was observed only for condition U4. UAE resulted in defatted solids (DS) with higher apparent density values, corroborating the increase in the amount of smaller diameter particles due to sonication. The micrographs showed changes in the surfaces of the solids from the UAE and PLE, although the crystalline structures of the DS were not altered. UAE and PLE, compared to conventional extraction, did not allow significant gains in terms of YSCGO and, consequently, in the number of contact stages in an extractor configured in cross-currents. Full article
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Review

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19 pages, 722 KiB  
Review
Potential Uses of Spent Coffee Grounds in the Food Industry
by Adriana S. Franca and Leandro S. Oliveira
Foods 2022, 11(14), 2064; https://0-doi-org.brum.beds.ac.uk/10.3390/foods11142064 - 12 Jul 2022
Cited by 18 | Viewed by 11772
Abstract
Current estimates place the amount of spent coffee grounds annually generated worldwide in the 6 million ton figure, with the sources of spent coffee grounds being classified as domestic (i.e., household), commercial (i.e., coffee houses, cafeterias and restaurants), and industrial (i.e., soluble and [...] Read more.
Current estimates place the amount of spent coffee grounds annually generated worldwide in the 6 million ton figure, with the sources of spent coffee grounds being classified as domestic (i.e., household), commercial (i.e., coffee houses, cafeterias and restaurants), and industrial (i.e., soluble and instant coffee industries). The majority of the produced spent coffee grounds are currently being inappropriately destined for landfills or to a form of energy recovery (e.g., incineration) as a refuse-derived fuel. The disposal of spent coffee in landfills allows for its anaerobic degradation with consequent generation and emission of aggressive greenhouse gases such as methane and CO2, and energy recovery processes must be considered an end-of-life stage in the lifecycle of spent coffee grounds, as a way of delaying CO2 emissions and of avoiding emissions of toxic organic volatile compounds generated during combustion of this type of waste. Aside from these environmental issues, an aspect that should be considered is the inappropriate disposal of a product (SCG) that presents unique thermo-mechanical properties and textural characteristics and that is rich in a diversity of classes of compounds, such as polysaccharides, proteins, phenolics, lipids and alkaloids, which could be recovered and used in a diversity of applications, including food-related ones. Therefore, researchers worldwide are invested in studying a variety of possible applications for spent coffee grounds and products thereof, including (but not limited to) biofuels, catalysts, cosmetics, composite materials, feed and food ingredients. Hence, the aim of this essay was to present a comprehensive review of the recent literature on the proposals for utilization of spent coffee grounds in food-related applications, with focus on chemical composition of spent coffee, recovery of bioactive compounds, use as food ingredients and as components in the manufacture of composite materials that can be used in food applications, such as packaging. Full article
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