Marcela Boroski

Combined electrocoagulation and TiO2 photoassisted treatment applied to wastewater effluents from pharmaceutical and cosmetic industries.

The treated wastewater consists of refractory materials and high organic content of hydrolyzed peptone residues from pharmaceutical factory. The combination of electrocoagulation (EC) followed by heterogeneous photocatalysis (TiO(2)) conditions was maximized. The EC: iron cathode/anode (12.50 cmx2.50 cmx0.10 cm), current density 763Am(-2), 90min and initial pH 6.0. As EC consequence, the majority of the dissolved organic and suspended material was removed (about 91% and 86% of the turbidity and chemical oxygen demand (COD), respectively). After EC, refractory residues still remained in the effluent. The subsequent photocatalysis: UV/TiO(2)/H(2)O(2) (mercury lamps), pH 3.0, 4h irradiation, 0.25gL(-1) TiO(2) and 10mmolL(-1) H(2)O(2) shows high levels of inorganic and organic compounds eliminations. The obtained COD values: 1753mgL(-1) for the sample from the factory, 160mgL(-1) after EC and 50mgL(-1) after EC/photocatalyzed effluents pointed out that the combined treatment stresses this water purification.

The effect of operational parameters on electrocoagulation-flotation process followed by photocatalysis applied to the decontamination of water effluents from cellulose and paper factories.

Cellulose and paper pulp factories utilize a large amount of water generating several undesirable contaminants. The present work is a preliminary investigation that associates the electrocoagulation-flotation (EC) method followed by photocatalysis to treat such wastewater. For EC, the experiment with aluminium and iron electrodes showed similar efficiency. Iron electrodes (anode and cathode) were chosen. By applying 30min of EC/Fe(0), 153A m(-2) and pH 6.0, the COD values, UV-vis absorbance and turbidity underwent an intense decrease. For the subsequent UV photocatalysis (mercury lamps) TiO(2) was employed and the favourable operational conditions found were 0.25g L(-1) of the catalyst and solution pH 3.0. The addition of hydrogen peroxide (50mmol L(-1)) highly increased the photo-process performance. By employing the UV/TiO(2)/H(2)O(2) system, the COD reduction was 88% compared to pre-treated effluents and complete sample photobleaching was verified. The salt concentration on EC (iron electrodes) showed that the electrolysis duration can be reduced from 30 to 10min by the addition of 5.0g L(-1) of NaCl. The biodegradability index (BOD/COD) increased from 0.15 (pre-treated) to 0.48 (after EC) and to 0.89 (after EC/photocatalysis irradiated for 6h), showing that the employed sequence is very helpful to improve the water quality. This result was confirmed by biotoxicity tests performed with microcrustaceous Artemia salina.

Quantification of essential fatty acids in the heads of nile tilapia (Oreochromis niloticus) fed with linseed oil

The objective of this study was to examine the effects of linseed oil on n-6 and n-3 polyunsaturated (PUFA) fatty acid content in the heads of Nile tilapia (Oreochromis niloticus), these are normally discarded during the filleting process. The quantification of PUFA was carried out in absolute weights through the use of methyl ester (23:0), as an internal standard, and TCFx (theoretical FID correction factor) by GC gas chromatography. Tilapias were given diets with increasing levels (0.00, 1.25, 2.50, 3.75 and 5.00%) of linseed oil as a replacement for sunflower oil (control) for a period of five months. The ingestion of LNA causes sequential desaturation and elongation in fish heads, leading to an increase in all n-3 PUFAs. This experiment demonstrated clearly that adding linseed oil to the feed of Nile tilapia can markedly increase the amounts (per 100 g-1 of head) of LNA (100.8 to 973.6 mg), EPA (4.8 to 82.1 mg), and DHA (24.0 to 125.4 mg) in their heads, and thus, may be used to help balance n-6/n-3 PUFA ratios in dietary supplements, and creating a valuable alternative food source in the human diet.

Evaluation of beetroot (Beta vulgaris L.) leaves during its developmental stages: a chemical composition study

Beetroot leaves (Beta vulgaris L.) are commonly cut off and discarded before using its bulb due to lack of knowledge of how to use them. Aiming at using these leaves, in the present study, in natura and dehydrated beetroot leaves were chemically characterized in terms of fatty acid composition, proximate composition, minerals, total phenolic compounds (TPC), and antioxidant activity by DPPH• in different stages (60, 80, and 100 days) of development. The beetroot leaves showed significant levels of protein and lipids in all developmental stages, and all proximate composition nutrients decreased during these maturation stages; the highest content was observed at 60 days. The Fe content decreased during the developmental stages (from 342.75 to 246.30 mg.kg-1), while the content of K increased (from 13,367.64 to 20,784.90 mg.kg-1). With regard to to fatty acid composition, linolenic acid was present in the greatest quantity, and it increase up to 2.58 mg.g-1 (in natura) and 40.11 mg.g-1 (dehydrated) at 100 days of development. The n-6/n-3 ratios were low in all stages. The TPC and antioxidant activity by DPPH• changed during the developmental stages. The TPC was highest in the 100-day dehydrated leaves (15.27±0.12 mg GAE.g-1 FW), and the 50% inhibition of DPPH• (IC50 89.52 µg.mL-1) were better in the 60-day in natura leaves. This study shows that all developmental stages produced satisfactory results, and therefore, these leaves can be reused as food. The antioxidant activity and the chemical constituents, mainly the ω-3fatty acid, increased during the stages of development.

Chemical characterization of leaves of organically grown carrot (Dacus carota L.) in various stages of development for use as food.

In Brazil, street markets and vegetable distributors discard vegetable leaves and stems, including those of carrot (Dacus carota L.). Seeking to reduce the waste of vegetable parts, this study characterized chemically the leaves of organically grown carrot in three stages of development to determine the best time for their removal and consumption as food. The leaves were dehydrated in an oven at 70 °C for 43 hours and analyzed for chemical composition, antioxidant activity, chlorophyll content, fatty acid composition, and also calcium (Ca), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), iron (Fe), zinc (Zn), and copper (Cu) contents. The analyses indicated 100 days of development as the ideal stage for the removal and consumption of carrot leaves with good antioxidant activity requiring only 63.78 ± 0.5 mg.L-1 methanol leaf extract to inhibit 50% of the concentration of the free radical DPPH (2,2-diphenyl-1picrilidrazil), and total protein and alpha-linolenic acid (18:3 n-3/LNA) contents of 18.23% ± 2.8 and 876.55 ± 20.62 mg.100 g-1 of dry matter, respectively.

Quantification of EPA and DHA in seafood of the south coast of Brazil

Purpose – The increase in seafood trade in recent years motivates more detailed studies of different species, as well as evaluation of the nutritional quality of their lipid content. Thus, the purpose of this paper is to evaluate the fatty acid composition, especially the concentrations and fractionation of omega‐3 essential fatty acid in classes of mussels (male and female), oysters, squid, and octopus captured on the south coast of Brazil.Design/methodology/approach – Fatty acid methyl esters were prepared by methylation of total lipids and were separated by gas chromatography. Quantification of LNA, AA, EPA, and DHA was done against tricosanoic acid methyl ester as an internal standard. Total lipids were fractionated into neutral lipids and polar lipids by classical column chromatography.Findings – The results of this study were as follows: the female mussel had the highest lipid content (3.52 per cent), followed by the male mussel (2.70 per cent), squid (1.05 per cent), octopus (0.79 per cent), and oy...

Proximate composition and quantification of fatty acids in breaded chicken steak

O objetivo deste estudo foi analisar a composicao centesimal e de acidos graxos de cinco marcas de steak empanado de frango (A, B, C, D e E). As analises de acidos graxos foram realizadas por cromatografia gasosa e tecnicas de quantificacao absoluta. Os resultados experimentais foram comparados com valores constantes nos rotulos. Os valores encontrados para proteina de todas as marcas estavam em acordo com o estabelecido pela legislacao brasileira, exceto o da amostra E, a qual apresentou o maior teor lipidico. Treze acidos graxos foram identificados nas marcas avaliadas, sendo os majoritarios os acidos: oleico, linoleico e palmitico. As razoes dos acidos graxos poli-insaturados/acidos graxos saturados encontraram-se dentro dos valores considerados adequados para a saude humana, porem, as elevadas razoes n-6/n-3 encontradas podem resultar em um desequilibrio na ingestao destes acidos graxos. Apenas amostras D e E podem ser consideradas livres de trans de acordo com a legislacao vigente. A comparacao entre os resultados das analises e os valores constantes nos rotulos apresentaram pequenas variacoes nos teores de proteina, entretanto, a maioria das marcas subestimou os teores de lipidios e valor energetico. Os rotulos das marcas B e C declaravam-se livre de trans, entretanto os resultados obtidos apontam teores acima dos valores permitidos pela legislacao para serem consideradas livre de trans.

Evaluation of omega-3 fatty acids content and antioxidant activity in wheat (Triticum aestivum L.) leaves

Conduziu-se este estudo, com o objetivo de quantificar o acido alfa-linolenico (LNA, 18:3n-3) em folhas de trigo secas e colhidas em diferentes estadios de desenvolvimento (20, 40 e 80 dias), determinar o potencial antioxidante e o conteudo de fenolicos totais em folhas colhidas aos 80 dias, assim como realizar a analise de minerais (Na, K, Fe, Ca, Mg, P, Zn, Cu e Mn). Foi verificada uma predominância de acidos graxos poli-insaturados (AGPI) comparado com os acidos graxos saturados (AGS) na fracao lipidica das folhas. As folhas colhidas em todos os periodos apresentaram razoes de AGPI/AGS e de acidos graxos omega-6 e omega-3 (n-6/n-3), dentro dos valores considerados adequados para a alimentacao. O maior teor de LNA foi encontrado nas folhas colhidas aos 60 dias, correspondendo a 2.146,72 mg 100 g-1 de materia seca. Entre 60 e 80 dias, observou-se uma queda de cerca de 30% na concentracao de LNA. A fracao acetato foi eficiente na inibicao do radical DPPH, apresentando valor de IC50 de 154 µg mL-1, e o teor de compostos fenolicos foi de 615,4 ± 36,4 mg EAG L-1, ambas as analises para as folhas colhidas aos 80 dias. Nesse estadio de crescimento, as folhas apresentaram consideraveis teores dos minerais P, Zn, Cu e Mn. Tais resultados reforcam a importância do uso de folhas de trigo para alimentacao humana, em funcao de seu potencial antioxidante e consideraveis teores de LNA.

Quantificação de ácido alfa-linolênico em caules e folhas de linho (Linum usitatissimum L.) colhidos em diferentes estágios de desenvolvimento

O objetivo deste estudo foi quantificar o acido alfa-linolenico [LNA, 18:3 (n-3)], avaliar a composicao centesimal das folhas e caules de linho (Linum usitatissimum L.) submetidos a secagem e colhidos em diferentes estagios de desenvolvimento (40, 80 e 120 dias), e determinar o potencial antioxidante das folhas colhidas aos 80 dias atraves do teste com o radical DPPH. As folhas obtiveram maiores teores de cinzas, proteina e lipidios totais em relacao aos caules. Tanto as folhas quanto os caules apresentaram razoes de AGPI/AGS e n-6/n-3 dentro dos valores considerados adequados para a alimentacao. Os caules colhidos nos diferentes tempos nao apresentaram diferencas significativas (P<0,05), quanto ao teor de LNA. As folhas colhidas aos 80 dias apresentaram a maior concentracao de LNA, correspondendo a 1,262,36 mg/100g de folhas desidratadas. Os diferentes extratos (metanolico, butanolico, acetato e aquoso) foram eficientes na inibicao do radical DPPH, com destaque para as fracoes butanolica e acetato, sendo os valores de IC50 de aproximadamente 42ppm para as duas fracoes. Tais resultados evidenciaram a atividade antioxidante e potencial nutritivo das folhas e caules de linho para futuro uso na alimentacao animal e humana.