Conventional and pressurized ethanolic extraction of oil from spent coffee grounds: Kinetics study and evaluation of lipid and defatted solid fractions

Author(s)

Toda, Tatiane Akemi ^[1] ; Visioli, Paola de Cassia Franco ^[1] ; de Oliveira, Alessandra Lopes ^[2] ; Rodrigues, Christianne Elisabete da Costa ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Zootec & Engn Alimentos FZEA, Lab Engn Separacoes LES, Dept Engn Alimentos ZEA, POB 23, BR-13635900 Pirassununga, SP - Brazil

^[2] Univ Sao Paulo, Fac Zootec & Engn Alimentos FZEA, Lab Tecnol Alta Pressao & Prod Nat LTAPPN, Dept Engn Alimentos ZEA, POB 23, BR-13635900 Pirassununga, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF SUPERCRITICAL FLUIDS; v. 177, NOV 2021.
• Web of Science Citations: 0

Abstract

Extraction kinetics of spent coffee grounds (SCG) soluble in absolute (ET0) and hydrous ethanol (ET6) in the temperature range of 60-150 celcius, under atmospheric and pressurized conditions, are discussed in this work. Solvent hydration negatively impacted oil extraction, while an increase in temperature led to higher relative yields (< 96.8%) during SCG oil (SCGO) extraction. At 150 <degrees>C, ET0 and ET6 exhibited similar SCGO extraction efficiencies. Free fatty acids and chlorogenic acid were extracted in less amounts. Thus, a change in the physicochemical characteristics of ET6 was observed at high temperatures. The solvent became less polar. Low (< 3.49%) average relative deviation values were obtained via mathematical modeling considering washing and diffusion steps. This helped in the estimation of SCGO diffusion coefficients. The values of the diffusion coefficients increased with temperature. The values were comparable to the values obtained when hexane was used as the extraction solvent. These findings reveal the SCGO extraction efficiency of ethanol, mainly under conditions of high pressure. (AU)

• FAPESP's process: 14/21252-0 - Equilibrium and production processes of biofuels and bioproducts
• Grantee: Antonio José de Almeida Meirelles
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 17/20840-4 - Valorization of agroindustrial coproducts through obtaining vegetable oils and minority compounds by extraction with solvents
• Grantee: Christianne Elisabete da Costa Rodrigues
• Support type: Regular Research Grants
• FAPESP's process: 17/12015-3 - Multi-user equipment approved in grant 2014/21252-0: professional IC vario two SeS/PP - ion chromatography
• Grantee: Antonio José de Almeida Meirelles
• Support type: Multi-user Equipment Program
• FAPESP's process: 17/10034-0 - Spent coffee grounds oil extraction using ethanol: Kinetics extraction, equilibrium data and process intensification
• Grantee: Tatiane Akemi Toda
• Support type: Scholarships in Brazil - Doctorate