title: Investigation of protocols to extraction and quantification of folates in vegetables matrices split into liquor and fiber fraction using factorial design.
abstract: The main protocols of extraction were investigated for the six folate forms in vegetable matrices, treated in two fractions, liquor and fiber. In a pilot study, it was used ammonium acetate added of 2-mercaptoetanol and ascorbic acid as extraction solution. The condition of use of protease and folate conjugase was evaluated, besides alternative treatments without enzyme use. Based on the results of this stage, it was built the factorial design 2(4), with three replications at the central point, using the following variables: temperature, time for reaction, molar concentration of the extraction solution and ratio sample/solution as independent variables and dependent variable, the amount of each folate form extracted as well as spectral and chromatographic parameters. In the pilot study it was verified that the enzyme use can cause an increase in the variability of the folate content, which enabled to build the factorial design without the enzyme use. The binomial time and temperature showed greatest impact on the extraction profile, besides high concentrations of ammonium acetate resulting in bifurcation of some peaks. 5-Methyltetrahydrofolate was extracted primordially in the liquor fraction, indicating that this treatment on the matrix provoked suitable extraction condition to this folate.
authors.affiliation: Departamento de Tecnologia Rural, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos, 52171-900 Recife, PE, Brazil. paiva.ufrpe@gmail.com
authors.forename: Emmanuela
authors.initials: E
authors.lastname: Prado de Paiva
authors.forename: Clayton
authors.initials: C
authors.lastname: Anderson de Azevedo Filho
authors.forename: Sabrina Gomes
authors.initials: SG
authors.lastname: Ferreira
authors.forename: Tânia Lucia Montenegro
authors.initials: TL
authors.lastname: Stamford
authors.forename: Jose Almiro
authors.initials: JA
authors.lastname: da Paixão
mesh_terms: D000085:Acetates / Q000737:chemistry; D000704:Analysis of Variance; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004043:Dietary Fiber / Q000032:analysis; D057230:Limit of Detection; D010936:Plant Extracts / Q000737:chemistry*; D015203:Reproducibility of Results; D012107:Research Design; D013763:Tetrahydrofolates / Q000032:analysis* / Q000302:isolation & purification*; D014675:Vegetables / Q000737:chemistry*
chemical_list: D000085:Acetates; D004043:Dietary Fiber; D010936:Plant Extracts; D013763:Tetrahydrofolates; C018824:ammonium acetate