Supercritical CO2 extraction of spent coffee grounds. Influence of co-solvents and characterization of the extracts

Coelho, José Augusto Paixão; Filipe, Rui M.; Robalo, M. Paula; Boyadzhieva, Stanislava; Cholakov, Georgi St.; Stateva, Roumiana P.

doi:10.1016/j.supflu.2020.104825

Cited by 39 publications

(28 citation statements)

References 58 publications

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“…Supercritical fluid extraction (SFE) was carried out in a laboratory apparatus from Applied Separations (model Spe-ed SFE-NP), which allows operation at pressures up to 60.0 MPa and temperatures up to 120 • C, equipped with a 50 cm 3 internal capacity extractor. A detailed description of the SFE apparatus is given elsewhere [38][39][40]. Briefly, liquid CO 2 flowing from a cylinder is compressed to the desired pressure using a circulating pump into the extractor, which is preheated to the desired temperature.…”

Section: Supercritical Fluid Extraction Apparatus and Proceduresmentioning

confidence: 99%

Supercritical Carbon Dioxide Extraction, Antioxidant Activity, and Fatty Acid Composition of Bran Oil from Rice Varieties Cultivated in Portugal

et al. 2021

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Bran of different rice cultivars produced in Portugal were used to study supercritical carbon dioxide extraction conditions of rice bran oil (RBO) and evaluate and compare antioxidant activity and fatty acid composition of the different rice bran varieties. The effect of plant loading (10–20 g), CO2 flow rate (0.5–1.5 L/min), pressure (20–60 MPa), and temperature (40–80 °C) was studied. The amount of oil extracted ranged from 11.72%, for Ariete cultivar, to 15.60%, for Sirio cultivar. The main fatty acids components obtained were palmitic (13.37%–16.32%), oleic (44.60%–52.56%), and linoleic (29.90%–38.51%). Excellent parameters of the susceptibility to oxidation of the oils were obtained and compare. RBO of Ariete and Gladio varieties presented superior DPPH and ABTS radical scavenging activities, whereas, Minima, Ellebi, and Sirio varieties had the lowest scavenging activities. Moreover, the oil obtained towards the final stages of extraction presented increased antioxidant activity.

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Section: Supercritical Fluid Extraction Apparatus and Proceduresmentioning

confidence: 99%

Supercritical Carbon Dioxide Extraction, Antioxidant Activity, and Fatty Acid Composition of Bran Oil from Rice Varieties Cultivated in Portugal

et al. 2021

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“…Among them, SCG are the main by-product remaining after processing coffee in the coffee beverage market, accounting for 50% of the total coffee bean production, and SCG generation is increasing daily with increases in coffee consumption [2]. Extensive attempts have been made to utilize SCG industrially, such as in active substance extraction [3], mushroom cultivation [4], and bioethanol production [1]. Despite these possibilities, the industrial application of SCG is still insufficient.…”

Section: Introductionmentioning

confidence: 99%

Antioxidant and Immunostimulatory Activities of a Submerged Culture of Cordyceps sinensis Using Spent Coffee

Han

Kim

Lee

et al. 2021

Foods

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Spent coffee grounds (SCG) are inexpensive materials that have been used as a source of antioxidants and polysaccharides with immunostimulatory activity. In this study, we performed a microbial fermentation of SCG using Cordyceps sinensis and investigated the radical scavenging and immunostimulatory activity of fermented SCG. SCG fermentation using C. sinensis was performed at 25 °C for 8 d. The polyphenol content of the fermented SCG increased from 1022.4 to 1562.0 μg/mL. The glucosamine content of the mycelia also continuously increased during fermentation. The main polyphenol compounds of fermented SCG were chlorogenic acid and p-coumaric acid, which were increased by fermentation. Fermented SCG also showed significantly higher content of chlorogenic acid isomers than unfermented SCG. The fermented SCG exhibited significantly higher 2,2-diphenyl-2-picrylhydrazyl hydrate (half maximal inhibitory concentration: IC50, 0.37 mg/mL) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50, 0.93 mg/mL) radical scavenging activities than those of the control (0.54 mg/mL and 1.20 mg/mL, respectively; p < 0.05). The fermented SCG stimulated macrophages and promoted the production of various immunostimulatory cytokines (IL-12, IL-6, and TNF-α) compared to control; therefore, microbial fermentation of SCG using C. sinensis is an effective means of generating antioxidant and immunostimulatory materials.

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“…Indeed, the extraction from grape pomace with the use of supercritical mixtures of CO 2 and water/ethanol (57% v / v ) as co-solvent was shown to give yields of 71.32 mg GAE (Gallic Acid Equivalents) per g of dry weight enriched in flavanols [ 96 ]. The increase of ethanol concentration added within (5–10%) increased the final yield and significantly decreased the extraction time from 100 to 58 min [ 103 ]. However, higher ethanol concentrations could hinder the extraction of the target compounds, since the hydrogen from the ethanol molecule may form hydrogen bonds with the oxygen of other molecules, increasing the required energy to separate ethanol molecules, causing a decrease in the process yield [ 103 ].…”

Section: Green Extraction Process: Synergism Between Solvents and Technologymentioning

confidence: 99%

Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

et al. 2021

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Nowadays, the food industry is heavily involved in searching for green sources of valuable compounds, to be employed as potential food ingredients, to cater to the evolving consumers’ requirements for health-beneficial food ingredients. In this frame, agri-food by-products represent a low-cost source of natural bioactive compounds, including antioxidants. However, to effectively recover these intracellular compounds, it is necessary to reduce the mass transfer resistances represented by the cellular envelope, within which they are localized, to enhance their extractability. To this purpose, emerging extraction technologies, have been proposed, including Supercritical Fluid Extraction, Microwave-Assisted Extraction, Ultrasound-Assisted Extraction, High-Pressure Homogenization, Pulsed Electric Fields, High Voltage Electrical Discharges. These technologies demonstrated to be a sustainable alternative to conventional extraction, showing the potential to increase the extraction yield, decrease the extraction time and solvent consumption. Additionally, in green extraction processes, also the contribution of solvent selection, as well as environmental and economic aspects, represent a key factor. Therefore, this review focused on critically analyzing the main findings on the synergistic effect of low environmental impact technologies and green solvents towards the green extraction of antioxidants from food by-products, by discussing the main associated advantages and drawbacks, and the criteria of selection for process sustainability.

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Supercritical CO2 extraction of spent coffee grounds. Influence of co-solvents and characterization of the extracts

Cited by 39 publications

References 58 publications

Supercritical Carbon Dioxide Extraction, Antioxidant Activity, and Fatty Acid Composition of Bran Oil from Rice Varieties Cultivated in Portugal

Supercritical Carbon Dioxide Extraction, Antioxidant Activity, and Fatty Acid Composition of Bran Oil from Rice Varieties Cultivated in Portugal

Antioxidant and Immunostimulatory Activities of a Submerged Culture of Cordyceps sinensis Using Spent Coffee

Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

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