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Yust BG, Wilkinson F, Rao NZ. Variables Affecting the Extraction of Antioxidants in Cold and Hot Brew Coffee: A Review. Antioxidants (Basel) 2023; 13:29. [PMID: 38247454 PMCID: PMC10812495 DOI: 10.3390/antiox13010029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/23/2024] Open
Abstract
Coffee beans are a readily available, abundant source of antioxidants used worldwide. With the increasing interest in and consumption of coffee beverages globally, research into the production, preparation, and chemical profile of coffee has also increased in recent years. A wide range of variables such as roasting temperature, coffee grind size, brewing temperature, and brewing duration can have a significant impact on the extractable antioxidant content of coffee products. While there is no single standard method for measuring all of the antioxidants found in coffee, multiple methods which introduce the coffee product to a target molecule or reagent can be used to deduce the overall radical scavenging capacity. In this article, we profile the effect that many of these variables have on the quantifiable concentration of antioxidants found in both cold and hot brew coffee samples. Most protocols for cold brew coffee involve an immersion or steeping method where the coffee grounds are in contact with water at or below room temperature for several hours. Generally, a higher brewing temperature or longer brewing time yielded greater antioxidant activity. Most studies also found that a lower degree of coffee bean roast yielded greater antioxidant activity.
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Affiliation(s)
- Brian G. Yust
- College of Humanities & Sciences, Thomas Jefferson University, Philadelphia, PA 19144, USA
| | - Frank Wilkinson
- Department of Biological and Chemical Sciences, College of Life Sciences, Thomas Jefferson University, Philadelphia, PA 19144, USA; (F.W.); (N.Z.R.)
| | - Niny Z. Rao
- Department of Biological and Chemical Sciences, College of Life Sciences, Thomas Jefferson University, Philadelphia, PA 19144, USA; (F.W.); (N.Z.R.)
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Hao W, Lee SH, Peera SG. Xerogel-Derived Manganese Oxide/N-Doped Carbon as a Non-Precious Metal-Based Oxygen Reduction Reaction Catalyst in Microbial Fuel Cells for Energy Conversion Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2949. [PMID: 37999303 PMCID: PMC10674280 DOI: 10.3390/nano13222949] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/11/2023] [Accepted: 09/18/2023] [Indexed: 11/25/2023]
Abstract
Current study provides a novel strategy to synthesize the nano-sized MnO nanoparticles from the quick, ascendable, sol-gel synthesis strategy. The MnO nanoparticles are supported on nitrogen-doped carbon derived from the cheap sustainable source. The resulting MnO/N-doped carbon catalysts developed in this study are systematically evaluated via several physicochemical and electrochemical characterizations. The physicochemical characterizations confirms that the crystalline MnO nanoparticles are successfully synthesized and are supported on N-doped carbons, ascertained from the X-ray diffraction and transmission electron microscopic studies. In addition, the developed MnO/N-doped carbon catalyst was also found to have adequate surface area and porosity, similar to the traditional Pt/C catalyst. Detailed investigations on the effect of the nitrogen precursor, heat treatment temperature, and N-doped carbon support on the ORR activity is established in 0.1 M of HClO4. It was found that the MnO/N-doped carbon catalysts showed enhanced ORR activity with a half-wave potential of 0.69 V vs. RHE, with nearly four electron transfers and excellent stability with just a loss of 10 mV after 20,000 potential cycles. When analyzed as an ORR catalyst in dual-chamber microbial fuel cells (DCMFC) with Nafion 117 membrane as the electrolyte, the MnO/N-doped carbon catalyst exhibited a volumetric power density of ~45 mW m2 and a 60% degradation of organic matter in 30 days of continuous operation.
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Affiliation(s)
| | - Sang-Hun Lee
- Department of Environmental Science, Keimyung University, Daegu 42601, Republic of Korea
| | - Shaik Gouse Peera
- Department of Environmental Science, Keimyung University, Daegu 42601, Republic of Korea
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Pagett M, Teng KS, Sullivan G, Zhang W. Reusing Waste Coffee Grounds as Electrode Materials: Recent Advances and Future Opportunities. GLOBAL CHALLENGES (HOBOKEN, NJ) 2023; 7:2200093. [PMID: 36618104 PMCID: PMC9818061 DOI: 10.1002/gch2.202200093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/05/2022] [Indexed: 06/17/2023]
Abstract
Coffee industry produces more than eight million tons of waste coffee grounds (WCG) annually. These WCG contain caffeine, tannins, and polyphenols and can be of great environmental concern if not properly disposed of. On the other hand, components of WCG are mainly macromolecular cellulose and lignocellulose, which can be utilized as cheap carbon precursors. Accordingly, various forms of carbon materials have been reportedly synthesized from WCG, including activated carbon, mesoporous carbon, carbon nanosheets, carbon nanotubes, graphene sheet fibers (i.e., graphenated carbon nanotubes), and particle-like graphene. Upcycling of various biomass and/or waste into value-added functional materials is of growing significance to offer more sustainable solutions and enable circular economy. In this context, this review offers timely insight on the recent advances of WCG derived carbon as value-added electrode materials. As electrodes, they have shown to possess excellent electrochemical properties and found applications in capacitor/supercapacitor, batteries, electrochemical sensors, owing to their low cost, high electrical conductivity, polarization, and chemical stability. Collectively, these efforts could represent an environmentally friendly and circular economy approach, which could not only help solve the food waste issue, but also generate high performance carbon-based materials for many electrochemical applications.
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Affiliation(s)
- Matthew Pagett
- Department of Chemical EngineeringSwansea UniversitySwanseaSA1 8ENUK
| | - Kar Seng Teng
- Department of Electronic and Electrical EngineeringSwansea UniversitySwanseaSA1 8ENUK
| | | | - Wei Zhang
- Department of Chemical EngineeringSwansea UniversitySwanseaSA1 8ENUK
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Yust BG, Rao NZ, Schwarzmann ET, Peoples MH. Quantification of Spent Coffee Ground Extracts by Roast and Brew Method, and Their Utility in a Green Synthesis of Gold and Silver Nanoparticles. Molecules 2022; 27:molecules27165124. [PMID: 36014362 PMCID: PMC9413573 DOI: 10.3390/molecules27165124] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/31/2022] [Accepted: 08/08/2022] [Indexed: 11/18/2022] Open
Abstract
Nanotechnology has become increasingly important in modern society, and nanoparticles are routinely used in many areas of technology, industry, and commercial products. Many species of nanoparticle (NP) are typically synthesized using toxic or hazardous chemicals, making these methods less environmentally friendly. Consequently, there has been growing interest in green synthesis methods, which avoid unnecessary exposure to toxic chemicals and reduce harmful waste. Synthesis methods which utilize food waste products are particularly attractive because they add value and a secondary use for material which would otherwise be disposed of. Here, we show that spent coffee grounds (SCGs) that have already been used once in coffee brewing can be easily used to synthesize gold and silver NPs. SCGs derived from medium and dark roasts of the same bean source were acquired after brewing coffee by hot brew, cold brew, and espresso techniques. The total antioxidant activity (TAC) and total caffeoylquinic acid (CQA) of the aqueous SCG extracts were investigated, showing that hot brew SCGs had the highest CQA and TAC levels, while espresso SCGs had the lowest. SCG extract proved effective as a reducing agent in synthesizing gold and silver NPs regardless of roast or initial brew method.
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Affiliation(s)
- Brian G. Yust
- Department of Physics, Thomas Jefferson University, East Falls Campus, Philadelphia, PA 19144, USA
- Correspondence: ; Tel.: +1-(215)-951-2879
| | - Niny Z. Rao
- Department of Chemistry and Biochemistry, Thomas Jefferson University, East Falls Campus, Philadelphia, PA 19144, USA
| | - Evan T. Schwarzmann
- Department of Chemistry and Biochemistry, Thomas Jefferson University, East Falls Campus, Philadelphia, PA 19144, USA
| | - Madisyn H. Peoples
- Department of Chemistry and Biochemistry, Thomas Jefferson University, East Falls Campus, Philadelphia, PA 19144, USA
- College of Computing & Informatics, Drexel University, 3675 Market St., Philadelphia, PA 19144, USA
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Li W, Sidhik S, Traore B, Asadpour R, Hou J, Zhang H, Fehr A, Essman J, Wang Y, Hoffman JM, Spanopoulos I, Crochet JJ, Tsai E, Strzalka J, Katan C, Alam MA, Kanatzidis MG, Even J, Blancon JC, Mohite AD. Light-activated interlayer contraction in two-dimensional perovskites for high-efficiency solar cells. NATURE NANOTECHNOLOGY 2022; 17:45-52. [PMID: 34811551 DOI: 10.1038/s41565-021-01010-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
Understanding and tailoring the physical behaviour of halide perovskites under practical environments is critical for designing efficient and durable optoelectronic devices. Here, we report that continuous light illumination leads to >1% contraction in the out-of-plane direction in two-dimensional hybrid perovskites, which is reversible and strongly dependent on the specific superlattice packing. X-ray photoelectron spectroscopy measurements show that constant light illumination results in the accumulation of positive charges in the terminal iodine atoms, thereby enhancing the bonding character of inter-slab I-I interactions across the organic barrier and activating out-of-plane contraction. Correlated charge transport, structural and photovoltaic measurements confirm that the onset of the light-induced contraction is synchronized to a threefold increase in carrier mobility and conductivity, which is consistent with an increase in the electronic band dispersion predicted by first-principles calculations. Flux-dependent space-charge-limited current measurement reveals that light-induced interlayer contraction activates interlayer charge transport. The enhanced charge transport boosts the photovoltaic efficiency of two-dimensional perovskite solar cells up to 18.3% by increasing the device's fill factor and open-circuit voltage.
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Affiliation(s)
- Wenbin Li
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, TX, USA
| | - Siraj Sidhik
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
- Institut FOTON, University Rennes, INSA Rennes, CNRS, Rennes, France
| | - Boubacar Traore
- Institut FOTON, University Rennes, INSA Rennes, CNRS, Rennes, France
- Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) -UMR 6226, Rennes, France
| | - Reza Asadpour
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Jin Hou
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Hao Zhang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, TX, USA
| | - Austin Fehr
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Joseph Essman
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Yafei Wang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Justin M Hoffman
- Department of Chemistry, Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Ioannis Spanopoulos
- Department of Chemistry, Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | | | - Esther Tsai
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Brookhaven, NY, USA
| | - Joseph Strzalka
- X-Ray Science Division, Argonne National Laboratory, Argonne, IL, USA
| | - Claudine Katan
- Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) -UMR 6226, Rennes, France
| | - Muhammad A Alam
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | - Mercouri G Kanatzidis
- Department of Chemistry, Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Jacky Even
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA
| | | | - Aditya D Mohite
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA.
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, TX, USA.
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