Validação de métodos para determinação dos ácidos fítico e oxálico em multimistura

Nappi, Giancarlo Ubaldo; Ribeiro-Cunha, Mariem Rodrigues; Coelho, José Virgílio; Jokl, Lieselotte

doi:10.1590/s0101-20612006000400016

Cited by 11 publications

(8 citation statements)

References 31 publications

(33 reference statements)

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“…The flours had higher oxalic acid content when compared to their in natura products. Nappi et al (2006) analyzed the level of oxalic acid in multimixtures (wheat, maize flour, egg shell, and manioc leaf) and obtained the value of 510 mg. sample kg -1 , an amount smaller than that found in the present study in yacon peel flour (PeF). However, the manioc leaf had high concentration of oxalic acid, between 444 mg.kg -1 and 570 mg.kg -1 of whole matter (WOBETO et al, 2007), which is higher than the levels found for the yacon and derived products in the present study, except for yacon peel flour.…”

Section: Resultsmentioning

confidence: 99%

Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

et al. 2013

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Due to the importance of studies on yacon related to health, its in natura pulp, in natura peel, pulp flour, and peel flour were chemically analyzed in terms of its centesimal composition, specific minerals, total dietary fiber and fractions, pH, total soluble solids, total titratable acidity, tannins, oxalic acid, and nitrate. The polyphenoloxidase and peroxidase enzymatic activities were evaluated for in natura pulp and peel only. Yacon pulp and peel flour presented average yield of 7.94% and 10.86%, respectively. The in natura pulp presented a higher moisture and carboydrate content and lower lipid, protein, total dietary fiber, and ash than those of the peel flour. The same pattern was observed for pulp flour when compared to peel flour. The highest tannin, nitrate, and oxalic acid levels were found in the peel flour, 15,304.5 mg.kg-1, 1,578.3 mg.kg-1, and 7,925.0 mg.kg-1 (wet weight), respectively. The polyphenoloxidase and peroxidase enzymes presented higher enzymatic activity in the yacon peel. Based on the results obtained, it can be said that the yacon and its derivatives are important dietary carbohydrate and mineral sources and contain antinutritional substance contents lower than those harmful to health.

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Section: Resultsmentioning

confidence: 99%

Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

et al. 2013

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“…The methodology was developed according to Nappi, Ribeiro‐Cunha, Coelho, and Jokl (). For IPs extraction, 0.5 g sample was mixed with 20 ml of an aqueous solution of 0.5 mol L −1 HCl and stirred for 2 hr at room temperature.…”

Section: Methodsmentioning

confidence: 99%

Modification of nutritional properties of whole rice flours ( Oryza sativa L. ) by soaking, germination, and extrusion

et al. 2019

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Modifications of nutritional properties (amino acids, available lysine, protein digestibility, fatty acids, fiber, inositol phosphate (IPs), free and bound phenolics, and antioxidant properties) of whole rice ingredients processed by soaking, germination, and/or extrusion cooking were evaluated. Soaking and germination reduced proteins by lixiviation and hydrolysis, respectively. Lysine was the limiting amino acid. Polyunsaturated fatty acids increased after germination. Protein digestibility was 100% for germinated rice, decreased to 75% after the extrusion process. Fiber content decreased around 73% after the extrusion of soaked and germinated flours. Soaking‐extrusion combined processes produces >50% IPs reduction. Germination‐extrusion produced flours with the highest antioxidant capacity (54 µmol trolox g−1), which was in accordance with the highest content of free and bound phenolics (66 and 69 mg GA 100 g−1, respectively). Grain treatments changed nutritional properties of flours resulting in low antinutrient whole grain ingredients, which could be used to develop whole grain‐based foods. Practical applications Phytic acid (PA) is an antinutrient having negative effects on mineral bioavailability and protein digestibility. There are processes such as soaking, germination, and extrusion, which alone or combined can decrease PA. However, nutritional composition and functionality of flours can change. We observed PA was highly reduced by soaking or germination combined with extrusion and antioxidant capacity and phenolic content increased in germinated and germinated‐extruded flours compared to the other treatments. These modified whole grain rice flours low in anti‐nutrients could be used in the production of expanded products or pre‐cooked ingredients to develop whole grain based foods nutritionally improved.

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“…Ultra-pure water and mobile phase have been used as sample diluent for HPLC analysis [46,47]. However, in the proposed method, the mobile phase with 32.5% methanol used as sample diluent presented a better chromatographic profile, obtaining a new profile with two peaks (3.27 and 6.24 min retention times) and a vacancy between them (Figure 3c).…”

Section: Organic Modifier (Methanol) As Mobile Phase and Sample Diluentmentioning

confidence: 98%

Chromatographic conditions evaluation for phytic acid (IP6) determination in rice bran samples by HPLC

Canan¹,

Delaroza²,

Kalschne³

et al. 2019

Br J Anal Chem

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Phytic acid (PA) or myo-inositol-1,2,3,4,5,6-hexakisphosphoric acid (IP6) can be hydrolyzed into inositol phosphates, such as inositol pentaphosphate (IP5), inositol tetraphosphate (IP4), inositol triphosphate (IP3) and possibly inositol di-and monophosphates (IP2 and IP1) by phytases (enzyme) during grains and seeds storage and fermentation. Chromatographic conditions of mobile phase, sample diluent, column and ionic par, for IP6 determination in defatted rice bran and purified PA from rice bran, were studied in this research. Linearity, repeatability, recovery, and limit of detection (LOD) and limit of quantification (LOQ) of the method were evaluated. The best resolution occurred with the use of both C18 columns (Shim-pack CLC-ODS and Novapak) at a 45 °C oven temperature and mobile phase A (32.50% methanol and 1.45% TBAH) and sample diluent da (32.50% methanol and 1.45% TBAH) and db (32.10% methanol and 1.20% TBAH). The R 2 of calibration curve was 0.9988, confirming the linearity in the PA range of 1.5 to 10 mg mL-1 (r = 0.9993; p < 0.0000). Intra-day repeatability presented relative standard deviations (RSD) of 3.43, 2.37 and 1.88% for 8, 5, and 3 mg mL-1 of PA concentrations, respectively. Inter-day intermediate precision RSD values were 0.93, 1.38, and 3.50% for each PA concentration, 8, 5, and 3 mg mL-1 respectively. RSD values were lower than 4% for both studies, demonstrating adequate repeatability and intermediate precision for the analytical method proposed. A 91% IP6 recovery was obtained and the LOD and LOQ were 0.05 and 0.15 mg mL-1 , respectively. The IP6 content in defatted rice bran and purified PA from rice bran samples were 3.90 and 420 mg 100 g-1 , respectively.

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Validação de métodos para determinação dos ácidos fítico e oxálico em multimistura

Cited by 11 publications

References 31 publications

Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

Studies of chemical and enzymatic characteristics of Yacon (Smallanthus sonchifolius) and its flours

Modification of nutritional properties of whole rice flours ( Oryza sativa L. ) by soaking, germination, and extrusion

Chromatographic conditions evaluation for phytic acid (IP6) determination in rice bran samples by HPLC

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