Nutritional evaluation after copper cloud point extraction in spirulina (Arthrospira sp.) samples with determination by digital image colorimetry

Uillian Mozart Ferreira Mata Cerqueira; Rebeca Moraes Menezes; Leane Santos Nunes; Valfredo Azevedo Lemos; Cleber Galvão Novaes; Marcos Almeida Bezerra

doi:10.1016/j.foodchem.2024.142592

Nutritional evaluation after copper cloud point extraction in spirulina (Arthrospira sp.) samples with determination by digital image colorimetry

Food Chem. 2024 Dec 26:470:142592. doi: 10.1016/j.foodchem.2024.142592. Online ahead of print.

Authors

Uillian Mozart Ferreira Mata Cerqueira¹, Rebeca Moraes Menezes², Leane Santos Nunes³, Valfredo Azevedo Lemos¹, Cleber Galvão Novaes³, Marcos Almeida Bezerra⁴

Affiliations

¹ Universidade Estadual do Sudoeste da Bahia, Campus de Jequié, Departamento de Ciências e Tecnologias, Rua José Moreira Sobrinho s/n, 45208-091 Jequié, Bahia, Brazil; Universidade Federal da Bahia, Instituto de Química, Campus da Federação/Ondina, Rua Barão de Geremoabo s/n, 40.170-115, Salvador, Bahia, Brazil.
² Universidade Estadual de Feira de Santana, Departamento de Exatas, Av. Transnordestina s/n, 44036-900 Feira de Santana, Bahia, Brazil.
³ Universidade Estadual do Sudoeste da Bahia, Campus de Jequié, Departamento de Ciências e Tecnologias, Rua José Moreira Sobrinho s/n, 45208-091 Jequié, Bahia, Brazil.
⁴ Universidade Estadual do Sudoeste da Bahia, Campus de Jequié, Departamento de Ciências e Tecnologias, Rua José Moreira Sobrinho s/n, 45208-091 Jequié, Bahia, Brazil; Universidade Federal da Bahia, Instituto de Química, Campus da Federação/Ondina, Rua Barão de Geremoabo s/n, 40.170-115, Salvador, Bahia, Brazil. Electronic address: mbezerra@uesb.edu.br.

PMID: 39787767
DOI: 10.1016/j.foodchem.2024.142592

Abstract

This study presents the development of a procedure based on copper preconcentration at the cloud point of commercial spirulina dietary supplements, with determination by digital image colorimetry. A fractional factorial design 2^4-1 and Doehlert matrix were applied in the method optimization. The developed method presented 0.062 and 0.20 mg kg^-1 Cu as limits of detection and quantification, respectively. The main advantages of this procedure come from the pre-concentration and the speed resulting from its direct determination in the surfactant-rich phase, eliminating the stage of discarding the original bulky aqueous phase. The found precision values, expressed as repeatability, were 2.8 % (5.0 μg L^-1) and 2.2 % (20 μg L^-1). Trueness was assessed using spike test and analysis of certified reference materials (Apple leaves and Oyster tissue), demonstrating that the method presents adequate trueness. Copper concentrations in the analyzed samples ranged from 19.92 to 55.32 mg kg^-1, representing a low nutritional contribution of 0.66-1.54 %, considering this supplement's recommended intake of 3 g day^-1.

Keywords: Cloud point extraction; Copper; Digital image colorimetry; Doehlert design; Nutritional assessment.