30A-7 |
Antioxidant activity of macambo (Theobroma bicolor L.) extracts |
J. MANCINI-FILHO1, R. Pavan Torres, and D. E. Garcia Torres. (1) Depto Alimentos e Nutrição Experimental, Faculdade de Ciências Farmacêuticas, University of São Paulo, Av. Prof. Lineu Prestes, 580 - Bloco 14, São Paulo, 05508-900, Brazil Lipid oxidation is the one main changes that can occur during processing, distribution, storage and final food preparation. The oxidation can be prevented by adding synthetic or natural antioxidants. In spite of safety of synthetic ones has been questioned. This situation promotes increasing demand for food additives of natural origin. Macambo is one fruit specie from Amazonia with high content of lipids (33%) that is used as food. Macambo samples were obtained from Amazonia, dried at 60oC, milled (32 mesh sieve) and submitted to sequencial extraction using as solvent: ether, ethanol and water. The antioxidant activity in the extracts was measured by the b-carotene/linoleic acid system, at 50oC and it absorbances reading at 470nm every 15 min intervals for 120 min. Two controls were used in this determination: one with synthetic antioxidant (BHT, 100ppm) and other without antioxidant. Phenolic fractions were obtained by tetrahydrofuran extraction. The phenolic acids were identified by gas chromatography equiped with cappilary column and flame ionization detector. The phenolic acids were identified on the basis of relative retention times compared with its standards. The etheric, ethanolic and aqueous extracts inhibited the oxidative process in 47%, 68% and 67% respectively, and the control BHT inhibited in 64%. Three fractions were obtained with tetrahydrofuran: free phenolic acids, soluble phenolic esters and unsoluble phenolic esters. The fractions obtained showed the presence of following phenolic acids: salicilic, trans-cinnamic, sinapinic, chlorogenic; protocatecnic, gallic, quimic, p.hydroxibenzoic. The presence phenolic compounds in macambo fruit extracts may be responsible for its higher antioxidant activity and the results obtained are suggesting that the macambo extracts can be used as food antioxidant. Further studies are in progress to analysing the sinergic association of the extracts with synthetic antioxidants and its use in the oil shelf life.
Session 30A, Food Chemistry: Lipids
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