Abstract Hydrocolloids of Pereskia aculeata Miller (OPNH) are potential ingredients in food industry as emulsifiers and stabilizers. The extraction process of OPNH requires the removal of pigments with activated carbon. Because this step is critical to the quality of the ingredient and has an impact on costs, a new activated carbon has been developed with residues from the same process. Residues activated with NaOH and H3PO4 (300 °C, 1 h) were subjected to batch adsorption tests in model solutions of malachite green (MG), carbohydrate and protein. Residue treated with 85% H3PO4 (OPNAC) had higher productivity and MG adsorption capacity, displaying a predominantly microporous surface (MEV/BET) with chemical activation confirmed by TG/FTIR. OPNAC showed higher MG and protein adsorption capacity than the commercial activated carbon (CAC) did. Results for MG-adsorption capacity by OPNAC did not show significant differences in the presence of protein and carbohydrate, presenting the higher affinity of the adsorbent for the dye. Adsorption isotherms showed OPNAC to be more favorable to MG adsorption than CAC, and to have a good fit to Langmuir-Freundlich model. OPNAC made it possible to reduce costs and allowed the sustainability of the process, leading to increased efficiency in selective pigment removal compared with CAC.

As alterações na concentração de cálcio ionizado (iCa) ocorrem nos recém-nascidos quando a fonte de cálcio proveniente da mãe é removida no momento do nascimento, resultando em hipocalcemia. Portanto, a verificação de iCa é de particular importância no recém-nascido. O objetivo deste estudo foi comparar dois métodos de determinação de iCa utilizados em laboratórios. Foram utilizadas 50 amostras de recém-nascidos que obtiveram valores de iCa pela medida direta e também pelo método indireto. Existe uma correlação significativa entre os valores de iCa obtidos utilizando Omni C e aqueles com o método calculado.

Changes in ionized calcium (iCa) concentration seem to occur in newborns when the calcium supply from the mother is disconnected at birth, and a related hypocalcemia is produced. Thus, measurement of iCa is of particular importance in newborns. The aim of this study was to compare two methods of iCa measurement. We collected 50 samples from newborns in which we obtained values of iCa using both the direct and the indirect measurement. There is a significant correlation between iCa values obtained from Omni C and those obtained from the calculated method.