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Prelac M, Major N, Cvitan D, Anđelini D, Repajić M, Ćurko J, Kovačević TK, Goreta Ban S, Užila Z, Ban D, Palčić I. Valorization of Olive Leaf Polyphenols by Green Extraction and Selective Adsorption on Biochar Derived from Grapevine Pruning Residues. Antioxidants (Basel) 2023; 13:1. [PMID: 38275621 PMCID: PMC10812658 DOI: 10.3390/antiox13010001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/15/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024] Open
Abstract
Given today's increasingly intensive agriculture, one key problem area considers the valorization and reuse of wastes from food and agricultural production with minimal impact on the environment. Due to its physicochemical characteristics, biochar (BC) derived from grapevine pruning residue has shown considerable potential for use as an adsorbent. High-value phytochemicals found in abundance in the olive leaf (OL) can be employed in many different industrial sectors. The potential application of BC in the removal of specific polyphenolic components from OL extracts has been investigated in the present study. Water, as the most available and greenest of solvents, was investigated as to its use in the extraction of polyphenols, which was carried out by comparing maceration, ultrasound-assisted extraction, and microwave-assisted extraction, considering different temperatures and solid-to-liquid (s/l) ratios. The BC adsorption capacity of selected polyphenols was fitted with both the Langmuir and Freundlich isotherm models. The Freundlich model fitted better relative to OL polyphenols adsorption. Oleuropein was the most abundant compound identified in the extracts, obtaining the highest Kf value (20.4 (mg/g) × (L/g)n) and R2 coefficient (0.9715) in the adsorption on the biochar's surface. The optimum conditions in the dosage experiment suggest the use of 0.5 g of BC using 3 g/L extracts, with an exception for oleuropein and hydroxytyrosol, for which the highest biochar dose (2.5 g) performed better. Considering the compounds' concentrations and the BC dose, BC from grapevine pruning residues demonstrated a potential use in the uptake of specific polyphenols from olive leaves, making it a promising adsorbent for such applications.
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Affiliation(s)
- Melissa Prelac
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Nikola Major
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Danko Cvitan
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Dominik Anđelini
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Maja Repajić
- Department of Food Engineering, University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia; (M.R.); (J.Ć.)
| | - Josip Ćurko
- Department of Food Engineering, University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia; (M.R.); (J.Ć.)
| | - Tvrtko Karlo Kovačević
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Smiljana Goreta Ban
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Zoran Užila
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Dean Ban
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
| | - Igor Palčić
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (I.P.)
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Prelac M, Palčić I, Cvitan D, Anđelini D, Repajić M, Ćurko J, Kovačević TK, Goreta Ban S, Užila Z, Ban D, Major N. From Waste to Green: Water-Based Extraction of Polyphenols from Onion Peel and Their Adsorption on Biochar from Grapevine Pruning Residues. Antioxidants (Basel) 2023; 12:1697. [PMID: 37760000 PMCID: PMC10525769 DOI: 10.3390/antiox12091697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/23/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Onion peels (OP) are rich in bioactive compounds with a plethora of benefits for human health, but this valuable material is often wasted and underutilized due to its inedibility. Likewise, grapevine pruning residues are commonly treated as agricultural waste, but biochar (BC) obtained from this material has favorable characteristics as an adsorbent. This study investigated the potential of BC in removal of targeted polyphenolic compounds from OP extracts. The OP extracts were obtained adhering to green chemistry principles using deionized water amplified by three methods: maceration (MAC), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE). The extraction efficiency on the polyphenolic profile and antioxidant capacity was investigated with different extraction temperatures and solid-to-liquid (s/l) ratios. For further analysis, UAE at 90 °C with an s/l ratio of 1:100 was used due to higher polyphenolic compound yield. The BC adsorption capacity of individual polyphenols was fitted with the Langmuir and Freundlich isotherm models. Quercetin-3,4'-diglucoside obtained the highest R2 coefficient in both models, and the highest qmax value. The optimum conditions in the dosage experiment suggested an amount of 0.5 g of BC using 3 g/L extracts. The studied BC showed a high affinity for targeted phytochemicals from OP extracts, indicating its potential to be applied for the green adsorption of valuable polyphenolic compounds.
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Affiliation(s)
- Melissa Prelac
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Igor Palčić
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Danko Cvitan
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Dominik Anđelini
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Maja Repajić
- Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia; (M.R.); (J.Ć.)
| | - Josip Ćurko
- Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia; (M.R.); (J.Ć.)
| | - Tvrtko Karlo Kovačević
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Smiljana Goreta Ban
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Zoran Užila
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Dean Ban
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
| | - Nikola Major
- Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia; (M.P.); (D.C.); (D.A.); (T.K.K.); (S.G.B.); (Z.U.); (D.B.); (N.M.)
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García-Rocha R, Durón-Torres SM, Palomares-Sánchez SA, Del Rio-De Santiago A, Rojas-de Soto I, Escalante-García IL. Effects of Heat Treatment on the Physicochemical Properties and Electrochemical Behavior of Biochars for Electrocatalyst Support Applications. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5571. [PMID: 37629862 PMCID: PMC10456742 DOI: 10.3390/ma16165571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/22/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023]
Abstract
The present work reports the synthesis and the physicochemical characterization of biochar from the organic wastes of nopal (Opuntia Leucotricha), coffee grounds (Coffea arabica) and Ataulfo mango seeds (Mangifera indica) as alternative electrocatalyst supports to Vulcan XC-72 carbon black. The biochars were prepared using pyrolysis from organic wastes collected at three temperatures, 600, 750 and 900 °C, under two atmospheres, N2 and H2. The synthesized biochars were characterized using Raman spectroscopy and scanning electron microscopy (SEM) to obtain insights into their chemical structure and morphological nature, respectively, as a function of temperature and pyrolysis atmosphere. A N2 adsorption/desorption technique, two-point conductivity measurements and cyclic voltammetry (CV) were conducted to evaluate the specific surface area (SSA), electrical conductivity and double-layer capacitance, respectively, of all the biochars to estimate their physical properties as a possible alternative carbon support. The results indicated that the mango biochar demonstrated the highest properties among all the biochars, such as an electrical conductivity of 8.3 S/cm-1 at 900 °C in N2, a specific surface area of 829 m2/g at 600 °C in H2 and a capacitance of ~300 mF/g at 900 °C in N2. The nopal and coffee biochars exhibited excellent specific surface areas, up to 767 m2/g at 600 °C in N2 and 699 m2/g at 750 °C in H2, respectively; nonetheless, their electrical conductivity and capacitance were limited. Therefore, the mango biochar at 900 °C in N2 was considered a suitable alternative carbon material for electrocatalyst support. Additionally, it was possible to determine that the electrical conductivity and capacitance increased as a function of the pyrolysis temperature, while the specific surface area decreased for some biochars as the pyrolysis temperature increased. Overall, it is possible to conclude that heat treatment at a high temperature of 900 °C enhanced the biochar properties toward electrocatalyst support applications.
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Affiliation(s)
- Rocío García-Rocha
- Doctorado Interinstitucional de Ingeniería y Ciencias de Materiales, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, Lomas 2da. Sección, San Luis Potosí 78210, Mexico;
| | - Sergio M. Durón-Torres
- Unidad Académica de Ciencias Químicas, Universidad Autónoma de Zacatecas, Campus Siglo XXI, Ed. 6, km. 6 Carr. Zacatecas-Guadalajara, Zacatecas 98160, Mexico;
| | | | - Antonio Del Rio-De Santiago
- Unidad Académica de Ingeniería Eléctrica, Universidad Autónoma de Zacatecas, Ramón López Velarde 801, Zacatecas 98000, Mexico; (A.D.R.-D.S.); (I.R.-d.S.)
| | - Ivone Rojas-de Soto
- Unidad Académica de Ingeniería Eléctrica, Universidad Autónoma de Zacatecas, Ramón López Velarde 801, Zacatecas 98000, Mexico; (A.D.R.-D.S.); (I.R.-d.S.)
| | - Ismailia L. Escalante-García
- Unidad Académica de Ciencias Químicas, Universidad Autónoma de Zacatecas, Campus Siglo XXI, Ed. 6, km. 6 Carr. Zacatecas-Guadalajara, Zacatecas 98160, Mexico;
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