Rapid Separation of Free Fatty Acids in Vegetable Oils by Capillary Zone Electrophoresis

Sato, Renata Takabayashi; Castro, Renata de Jesus Coelho; Barra, Patrícia Mendonça de Castro; Oliveira, Marcone Augusto Leal de

doi:10.1002/pca.2499

Cited by 15 publications

(24 citation statements)

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“…22 Do ponto de vista formal, pressupostos como independência, homocedasticidade e normalidade devem ser verificados, a fim de garantir a confiabilidade das informações a serem inferidas. Dentro deste contexto, no intuito de verificar se o modelo proposto apresenta comportamento linear adequado, todos os experimentos na etapa descritiva foram realizados aleatoriamente a partir de uma solução padrão estoque de concentração definida (independência), e as respostas de sinais obtidas a partir das leituras submetidas ao teste de Cochran (teste de homocedasticidade), verificação da falta de ajuste do modelo através do teste ANOVA a priori e, por fim, avaliação da normalidade nos resíduos (teste de Shapiro-Wilk).…”

Section: Resultados E Discusão Ajuste Dos Modelos Para Quantificação unclassified

“…Métodos espectrofotométricos têm sido usualmente utilizados para determinação de alguns constituintes químicos em matrizes alimentícias [4][5][6][7][8][9][10][11] devido à fácil aplicação, eficácia e eficiência aceitáveis, e baixo custo quando comparados a métodos analíticos mais sofisticados como, por exemplo, cromatografia à líquido de alta eficiência (CLAE), 12,13 cromatografia a gás (CG), [14][15][16] cromatografia por fluido supercrítico (CFS) [17][18][19] e eletroforese capilar (EC) [20][21][22][23] associados a detectores compatíveis com cada sistema de separação.…”

Section: Introductionunclassified

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Spectrophotometric Determination of Wpni and HMF in Uht Milk Through the Principal Components Analysis

Neves¹,

Silva²,

Oliveira³

2016

Química Nova

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SPECTROPHOTOMETRIC DETERMINATION OF WPNI AND HMF IN UHT MILK THROUGH THE PRINCIPAL COMPONENTS ANALYSIS.During heat treatment milk suffers changes among which whey proteins insolubility and Maillard reaction can be monitored using spectrophotometric methods by determining the whey protein nitrogen (WPNI) and 5-hydroxymethylfurfural (HMF). The aim of this work was the evaluation of heat treatment in commercial UHT milk samples through HMF and WPNI determination by spectrophotometric methods in visible region, using chemometric tools in data analysis. The regression models were fitted and statistical assumptions were tested. The WPNI confidence interval (CI) was (0.91; 3.73) mg mL -1 showing the heat treatment severity and classifying the samples as "medium heat treatment" according to American Dairy Products Association. For free HMF index, the CI were: (2.39; 3.27) and (6.01; 6.89) µmol L -1 for regular and low lactose content samples, respectively; while these two samples group presented CI of (11.67; 12.39) and (132.28; 143.22) µmol L -1 for total HMF index, respectively; showing the influence of lactose content in total HMF index. Descriptive statistical analysis associated with principal component analysis demonstrated a lack of standardization in the current Brazilian UHT process. The spectrophotometric methods allowed obtaining further inferences about the product quality associated to its heat treatment.Keywords: Maillard reaction; denaturation; chemometric; quality control. INTRODUÇÃODurante o processamento térmico o leite sofre modificações devido à ação do calor, dentre as quais tem-se a insolubilização das soroproteínas e a reação entre proteínas e lactose, denominada reação de Maillard (RM).1 Especificamente estas duas modificações químicas causadas pela ação do calor geram compostos capazes de serem determinados através de métodos espectrofotométricos, 2,3 permitindo monitorar e controlar a severidade do tratamento térmico aplicado ao produto.Métodos espectrofotométricos têm sido usualmente utilizados para determinação de alguns constituintes químicos em matrizes alimentícias 4-11 devido à fácil aplicação, eficácia e eficiência aceitáveis, e baixo custo quando comparados a métodos analíticos mais sofisticados como, por exemplo, cromatografia à líquido de alta eficiência (CLAE), 12,13 cromatografia a gás (CG), 14-16 cromatografia por fluido supercrítico (CFS) 17-19 e eletroforese capilar (EC) 20-23 associados a detectores compatíveis com cada sistema de separação.A metodologia proposta por Kuramoto et al. 2 para determinação do índice de soroproteína não desnaturada ou whey protein nitrogen index (WPNI) via turbidimetria utiliza o princípio de "salting out" com adição de cloreto de sódio em excesso. Sabe-se que ao aumentar a força iônica de um meio há a tendência na redução da capacidade solvente da água e, consequentemente, da espessura da dupla camada elétrica que envolve as proteínas. A redução de tais efeitos estabilizadores proporciona uma efetiva perda de solubilidade protéica gerando preci...

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Section: Resultados E Discusão Ajuste Dos Modelos Para Quantificação unclassified

Section: Introductionunclassified

Spectrophotometric Determination of Wpni and HMF in Uht Milk Through the Principal Components Analysis

Neves¹,

Silva²,

Oliveira³

2016

Química Nova

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“…For example, the established value for olive oil acidity is 1.0% (1 g/100 g). 14 However, there is no legislation regarding the free acidity in pequi oil, but this oil is widely used in food preparation and in traditional dishes. According to Table 2, of the four different samples of pequi oil tested, oil 1 presented the best quality over the others, due to the lowest levels of FFA, while oil 4 presented the highest concentration of all the analyzed FFA and the highest acidity (highest oleic acid concentration).…”

Section: Resultsmentioning

confidence: 99%

“…12 In recent years, capillary zone electrophoresis (CZE) has been applied to the determination of major FA in samples such as edible oils, olive oil, soy oils, butter and margarine, with faster and simpler analytical methods since the derivatization reaction is not required during sample preparation. 12,14,15 However, there have been no studies in the literature involving the determination of FA in pequi oil by CZE. Furthermore, the free acidity, expressed according to the free fatty acid (FFA) content, is an important quality parameter of oil samples.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the free acidity, expressed according to the free fatty acid (FFA) content, is an important quality parameter of oil samples. 14 The pequi fruit is also an important source of micronutrients essential to human health, such as Cu, Fe, Mn e Zn. 16,17 These micronutrients, known as trace elements, can be ingested through food and water and have a variety of biochemical functions in living organisms, but they can be toxic when taken in excess.…”

Section: Introductionmentioning

confidence: 99%

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DETERMINATION OF Cu, Fe, Mn, Zn AND FREE FATTY ACIDS IN PEQUI OIL

Mimura¹,

Faza²,

Marques³

et al. 2016

Química Nova

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Recebido em 31/08/2015; aceito em 04/02/2016; publicado na web em 15/04/2016 Pequi (Caryocar brasiliense Camb.), a typical fruit of the Brazilian Cerrado, is an important source of micronutrients and fatty acids. In this work, a new approach for the acid digestion (using H 2 SO 4 , HNO 3 and H 2 O 2 ) of pequi oil samples and the determination of Cu, Fe, Zn and Mn by flame atomic absorption spectrometry (F AAS) was employed. Capillary zone electrophoresis (CZE) was used for free fatty acid (FFA) determination after simple and fast extraction with heated ethanol. Good results regarding precision (RSD < 10%, in most cases), sensitivity and adequate LOD and LOQ values were obtained. The accuracy was evaluated using spike tests and the recoveries were from 97 to 107%. The analytes were investigated in four different pequi oil samples. Fe was the trace element with the highest concentration (from 1.99 to 10.3 mg/100 g), followed by Zn, Mn and Cu (1.15 to 3.19, 0.42 to 0.91 and 0.31 to 0.56 mg/100 g, respectively). The main FFA found were oleic acid and palmitic acid (1.61 to 10.7 and 0.82 to 2.69 g/100 g, respectively), while linoleic acid (0.50 g/100 g) was detected in only one sample. The pequi oil chemical composition showed good characteristics to be used as a food additive, in cosmetic formulations and for traditional medicine.

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Classification of Tunisian extra virgin olive oils according to their genetic variety and maturity index using fatty acid profiles established by direct infusion mass spectrometry

Abdallah

Vergara‐Barberán²,

Lerma‐García³

et al. 2015

Euro J Lipid Sci & Tech

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The usefulness of fatty acid profiles established by direct infusion mass spectrometry (DIMS) as a tool to discriminate between seven genetic varieties of Tunisian extra virgin olive oils (EVOOs) was evaluated in this work. Moreover, the discrimination of EVOOs from the genetic varieties Chemchali, Fouji, and Zarrazi, characterized with different maturity indices, was also studied. For DIMS, EVOO samples were diluted with an 85:15 propanol/methanol (v/v) mixture containing 40 mM ammonia and directly infused into the mass spectrometer using a syringe pump. The establishment of ratios of the peak abundances of the free fatty acids followed by linear discriminant analysis was employed to predict both genetic variety and maturity index. In all cases, an excellent resolution between all category pairs was achieved, which demonstrated that fatty acid profiles are a good marker of both genetic variety and maturity index of EVOOs.Practical applications: As EVOO quality can be affected by different parameters, such as cultivar and maturity index, among others, it is necessary to develop analytical methods able to verify EVOO quality, and also to control its origin as olive oil producers have to include in their manufactured products the cultivar (monovarietal oils) from which the oil was obtained. Currently, almost all the research related to Tunisian EVOOs has been mainly focused on the improvement and characterization of the two main cultivars (Ch etoui and Chemlali). Thus, to diversify Tunisian olive oil resources and improve the quality of olive oil produced in Tunisia, research on additional cultivars needs to be conducted. Thus, the present method could be used as an authentication tool for olive oil industry to asses both cultivar and maturity index of Tunisian EVOO, which could be extended to EVOO from all around the world.

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Rapid Separation of Free Fatty Acids in Vegetable Oils by Capillary Zone Electrophoresis

Abstract: The main advantage to the proposed method is the possibility to observe the individual amount of the free fatty acids, which would be useful for researchers interested in studying the effect of the free fatty acids profile on oxidative process in food.

Cited by 15 publications

References 22 publications

Spectrophotometric Determination of Wpni and HMF in Uht Milk Through the Principal Components Analysis

Spectrophotometric Determination of Wpni and HMF in Uht Milk Through the Principal Components Analysis

DETERMINATION OF Cu, Fe, Mn, Zn AND FREE FATTY ACIDS IN PEQUI OIL

Classification of Tunisian extra virgin olive oils according to their genetic variety and maturity index using fatty acid profiles established by direct infusion mass spectrometry

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