Validação de métodos cromatográficos por clae para análise das vitaminas B1, B2, B6 e niacina naturalmente presentes em farinha de cereais

Abstract

Complex B vitamins are present in some cereal foods and the ingestion of enriched products contributes to the recommended dietary intake of these micronutrients. To adapt the label of some products, it is necessary to develop and validate the analytical methods. These methods must be reliable and with enough sensitivity to analyze complex B vitamins naturally present in food at low concentration. The purpose of this work is to evaluate, with validated methods, the content of vitamins B 1 , B 2 , B 6 and niacin in five cereal flours used in food industry (oat, rice, barley, corn and wheat). Figura 5.Cromatogramas de niacina: solução padrão e amostra de farinha de aveia (Fase móvel: tampão fosfato (0,954% KH 2 PO 4 ) em solução de 0,76% de peróxido de hidrogênio 30 e 0,1% de solução de sulfato de cobre 5 mM, Fluxo: 1,1 mL/min, Coluna: C 18 de fase reversa Nucleosil 100-5 C 18 , marca Macherey-Nagel, Volume de injeção: 20 µL, Reator composto por 12 m de tubulação de tetrafluoretileno (TFE), 0,5 mm de diâmetro interno, enrolada em uma lâmpada negra que emite radiação entre 300 a 400 nm e detecção por fluorescência: Ex 322 nm; Em 380 nm)

Methods for analysis of thiamin and folic acid by HPLC—DAD in fortified rice pure and mixed to milled rice before and after different cooking techniques

“…These values are within the range of 80 to 110% set by the AOAC [28]. Studies were found in the literature with similar percentages for the recovery of thiamin, of between 73 to 106% [21,23,24] and 81 to 103% for folic acid [25,27,29]. …”

“…The value found for thiamin was lower than the limits of detection found by Hucker et al [24], Presoto and AlmeidaMuradian [25], and San José Rodriguez [22], being 0.02 μg, 0.03 μg, and 0.06 μg, respectively. In relation to folic acid, values of 0.003 μg, 0.0013 μg, and 0.06 μg were found by Boen et al [26], Lebiedziñska et al [27], and Alaburda et al [28], respectively.…”

“…The coefficient of determination for thiamin and folic acid was 0.9998 and 0.9997, respectively. Studies analyzing these vitamins found coefficients of determination for thiamin of 0.9957 [21], 0.9967 [22], 0.9998 [23], and 0.9950 [24] and for folic acid of 0.9838 [22], 0.9997 [25], 0.9980 [26], and 0.9999 [27].…”

Processing and characterization of extruded breakfast meal formulated with broken rice and bean flour

“…The following determinations were also performed for the breakfast flake: water activity (direct measurement using a water activity analyzer DECAGON, model Pawkit, Pullman USA); thiamine (vitamin B1) content (EUROPEAN…, 2003a), pre-column derivation by thiochrome according to Presoto and Almeida-Muradian, 2008;and Riboflavin (vitamin B2) (EUROPEAN…, 2003b) by High Performance Liquid Chromatography (HPLC), according to methods standardized by the European Commission for Standardization.…”

Vitamin and bioactive compound diversity of seven fruit species from south Brazil

“…For the riboflavin, a linear mobile phase [a mixture of potassium phosphate buffer pH 7.2 with dimethylformamide 85:15 ( v / v )] was used for 10 min, with excitation of 450 nm and emission of 530 nm. For pyridoxine analysis the mobile phase consisted of potassium phosphate buffer pH 2.5 and acetonitrile 94:4 ( v / v ) for 6 min, with an excitation of 296 nm and emission of 390 nm . The thiamine and niacin were separated using as mobile phase a linear gradient initial elution of sodium phosphate buffer pH 3.0/methanol at 98:2 ( v / v ) to 40:60 ( v / v ) over 9 min, and 98:2 ( v / v ) for up to 15 min.…”