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

Abstract

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.

Fatty acids analysis by capillary electrophoresis: Fundamentals, advantages and applications

“…Focusing on the use of TSH capillary, combined with the BGE composition of 15 mM NaH 2 PO 4 /Na 2 HPO 4 buffer (pH 7), 4 mM SDBS, 8.3 mM Brij R 35, 45% v/v ACN, and 2.1% v/v 1-octanol, this methodology was applied to determine FAs over the years. Hydrogenated vegetable fat, butter, margarine, and filled cookies [11], pequi fruits [30,34], extra virgin olive oil, virgin olive oil, soybean oil, and biodiesel [11,32,36], forages [29], analysis of FAs in liver rats submitted to a specific diet [31], chocolates [33], milk adulteration [35], and bottled butter [10], have been analyzed by CE, showing the potential of this method for the determination of a range of FAs in challenging samples and different applications. However, some works used the same BGE with TSP capillary for analysis of FAs in olive oil [26], in hydrogenated vegetable fat, and in spreadable processed cheese [27,28], in pumpkin seed oil and moisturizing cream with this oil in its composition [6], in encapsulated vegetable oil supplements [7], and in hops [38].…”

“…Considering the wide variety of samples, an essential step is their preparation, as mentioned previously. In this context, in 2016, Mimura et al performed ethanolic extraction as a simple sample preparation, which is suitable for determining C16:0, C18:1c, and C18:2cc free FA content in pequi oil samples [34]. Extraction with EtOH was also carried out in the works of Balesteros et al and Sato et al for the determination of the same analytes in different oils [26,32], all that considering the quantitative evaluation of the free acidity in terms of FAs, which means, the FA content is not associated with glycerol, therefore, saponification is not required.…”

“…Illustrating this relevance, the review papers of Klampfl et al and Amorim et al covered the use of this technique for the determination of FAs in food and beverage samples, and in vegetable and marine oils, respectively [37,39]. In addition, developing fast and easy-to-treat sample methods is essential for determining FAs because this content can serve as an important parameter for the quality control of many products [6,34,35]. Therefore, in 2016, Mendes et al showed the possibility of detecting fraud in milk by adding protein powder, commonly known as whey protein, using the difference in the FAs profile in milk and whey [35].…”

“…In this context, in 2016, Mimura et al. performed ethanolic extraction as a simple sample preparation, which is suitable for determining C16:0, C18:1c, and C18:2cc free FA content in pequi oil samples [34]. Extraction with EtOH was also carried out in the works of Balesteros et al.…”

Revisão integrativa do uso do óleo do pequi (Caryocar brasiliense) no processo de cicatrização de feridas cutâneas em ratos

“…O resultado desses processos, são sinais clínicos que possuem como características calor, rubor, edema, dor, perda de função. O óleo de pequi tem como principal ação farmacológica de inibir esses processos metabólicos (Mimura, A. et al 2016).…”