Trabalho 19 – Adriana Pereira dos Santos Marques – USE OF POLYSACCHARIDES TO STABILIZE BARU OIL MICROEMULSIONS

poster 19

USE OF POLYSACCHARIDES TO STABILIZE BARU OIL MICROEMULSIONS

A.P.S. Marques1*, W.H. Ferreira2, E.G. AZERO3, G.H. Silva4, A.G. TORRES1 AND

C.T. ANDRADE2

1Universidade Federal do Rio de Janeiro, Instituto de Química

2Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas

3Universidade Federal do Estado do Rio de Janeiro, Instituto de Biociências

4Universidade Federal do Rio de Janeiro, Faculdade de Farmácia

E-mail: adriana_marques@id.uff.br

Nuts from the native Brazilian shrub baru (Dipteryx alata Vog.) have been found to be of high nutrition value. However, not much attention has been given to the oil extracted from those nuts. In this work, natural baru nuts and nuts roasted at 105ºC for 25 and 35 s were submitted to cold extraction under compression. The oil samples, obtained at 31 – 35% yield, were characterized and used to prepare emulsions. The roasting conditions affected (P < 0.5) the acidity, peroxide and refractive indexes, as well as the density of the samples. The chemical structure was characterized by infrared spectroscopy (FTIR), and the characteristic absorptions, attributed to out-of-plane cis-olefinic C-H bending vibrations, were observed in the spectra. The fatty acid and tocopherol compositions were investigated. Polyunsaturated fatty acids reached a high content, around 79% of fatty acids. The contents of total tocopherol varied between 28 and 30%, and a-tocopherol was determined at concentrations that varied between 14 and 20%. To prepare o/w emulsions, the recommended total concentration (0.5% m/m) of the synthetic surfactants Tween 20 and Span 80 was used, together with polysaccharides. Complex coacervation between the polycationic chitosan and polyanionic sodium alginate was used to encapsulate the baru oil, with efficiencies of 78 -85%. High-methoxyl pectin was added as a stabilizing agent at 0.1 – 0.5% concentrations. The resulting microemulsions, maintained stable for at least 70 days, were characterized by rheological measurements. Dynamic oscillatory experiments revealed a solid-like behavior, whereas steady state measurements showed the characteristic pseudoplastic feature.

Financial Support: FAPERJ, CAPES and CNPq  Area: Food Science

Download: Resumo Adriana Marques (formato pdf)

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