1
|
de Souza PG, Pallone JAL, Orlando EA, Costa-Santos AC, Ayres EMM, Rosenthal A, Teodoro AJ. Evaluation of oxalic acid extraction and quantification methods in the different purslane ( Portulaca oleracea L.) matrices and spinach ( Spinacea oleracea). MethodsX 2024; 13:102863. [PMID: 39157815 PMCID: PMC11326941 DOI: 10.1016/j.mex.2024.102863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 07/12/2024] [Indexed: 08/20/2024] Open
Abstract
Purslane (Portulaca oleracea) and spinach (Spinacea oleracea) are species with elevated levels of oxalic acid, an antinutrient that interferes in the bioaccessibility of minerals such as calcium and iron. Evaluating methods to determine oxalic acid content with reduced matrix interference, such as employing Flame Atomic Absorption Spectrometry (FAAS), can enhance the specificity of determinations. The different matrices of purslane (whole plant, leaves, and juice) and spinach (whole plant) were tested using three extraction methods (M1, M2, and M3). The oxalic acid content was evaluated by UV-vis spectrophotometry and FAAS (Flame Atomic Absorption Spectrometry). The absence of the precipitation step in M1 resulted in high levels of oxalic acid in the investigated matrices. The quantification of oxalic acid by FAAS for M2 (6M HCl for 1 hour at 100°C) and M3 (0.25N HCl for 15 minutes at 100°C) in the samples of purslane leaves and spinach whole plants yielded statistically similar results. However, the analysis by UV-vis spectrophotometry for M2 and M3 showed significant discrepancies in all evaluated samples, suggesting interference from colored compounds in the food matrix.•Comparison of methods of extraction•Comparison of UV-vis spectrophotometer and FAAS in the quantification of oxalic acid•Analysis of antinutrients in plant matrices.
Collapse
Affiliation(s)
- Pâmela Gomes de Souza
- Laboratory of Food Analysis, Graduate Program in Food Nutrition, Fluminense Federal University, Rua Mário Santana Braga, 30 - Niteroi, RJ, Brazil
| | - Juliana Azevedo Lima Pallone
- Laboratory of Food Analysis by Spectroscopy, Faculty of Food Engineering, State University of Campinas, Rua Monteiro Lobato, 80 Barão Geraldo, Campinas, SP, Brasil
| | - Eduardo Adilson Orlando
- Laboratory of Food Analysis by Spectroscopy, Faculty of Food Engineering, State University of Campinas, Rua Monteiro Lobato, 80 Barão Geraldo, Campinas, SP, Brasil
| | - Augusto César Costa-Santos
- Laboratory of Food Analysis by Spectroscopy, Faculty of Food Engineering, State University of Campinas, Rua Monteiro Lobato, 80 Barão Geraldo, Campinas, SP, Brasil
| | - Ellen Mayra Menezes Ayres
- Sensory and Consumer Science Laboratory, Postgraduate Program in Food and Nutrition, Federal University of the State of Rio de Janeiro Laboratorio, Av. Pasteur -Urca, 29, Rio de Janeiro, Brazil
| | - Amauri Rosenthal
- Embrapa Food Technology, Av. das América, 29501, Guaratiba, Rio de Janeiro, RJ, Brazil
| | - Anderson Junger Teodoro
- Laboratory of Food Analysis, Graduate Program in Food Nutrition, Fluminense Federal University, Rua Mário Santana Braga, 30 - Niteroi, RJ, Brazil
| |
Collapse
|
2
|
Salgado N, Silva MA, Figueira ME, Costa HS, Albuquerque TG. Oxalate in Foods: Extraction Conditions, Analytical Methods, Occurrence, and Health Implications. Foods 2023; 12:3201. [PMID: 37685134 PMCID: PMC10486698 DOI: 10.3390/foods12173201] [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: 07/31/2023] [Revised: 08/19/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
Oxalate is an antinutrient present in a wide range of foods, with plant products, especially green leafy vegetables, being the main sources of dietary oxalates. This compound has been largely associated with hyperoxaluria, kidney stone formation, and, in more severe cases, systematic oxalosis. Due to its impact on human health, it is extremely important to control the amount of oxalate present in foods, particularly for patients with kidney stone issues. In this review, a summary and discussion of the current knowledge on oxalate analysis, its extraction conditions, specific features of analytical methods, reported occurrence in foods, and its health implications are presented. In addition, a brief conclusion and further perspectives on whether high-oxalate foods are truly problematic and can be seen as health threats are shown.
Collapse
Affiliation(s)
- Neuza Salgado
- Research and Development Unit, Department of Food and Nutrition, National Institute of Health Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal (T.G.A.)
- Faculty of Pharmacy, University of Lisbon, Avenida Professor Gama Pinto, 1649-003 Lisbon, Portugal
| | - Mafalda Alexandra Silva
- Research and Development Unit, Department of Food and Nutrition, National Institute of Health Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal (T.G.A.)
- REQUIMTE-LAQV/Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Maria Eduardo Figueira
- Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Avenida Professor Gama Pinto, 1649-003 Lisbon, Portugal
| | - Helena S. Costa
- Research and Development Unit, Department of Food and Nutrition, National Institute of Health Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal (T.G.A.)
- REQUIMTE-LAQV/Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Tânia Gonçalves Albuquerque
- Research and Development Unit, Department of Food and Nutrition, National Institute of Health Dr. Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal (T.G.A.)
- REQUIMTE-LAQV/Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| |
Collapse
|
3
|
Rapid Optimization of Reaction Conditions Based on Comprehensive Reaction Analysis Using a Continuous Flow Microwave Reactor. CHEM REC 2018; 19:77-84. [DOI: 10.1002/tcr.201800048] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/19/2018] [Indexed: 01/24/2023]
|