CONICET | Buscador de Institutos y Recursos Humanos

The demand for natural products with functional activities has been the subject of many recent studies. In the agro-food sector, several materials are eliminated (such as skins, seeds and pulp remnants) as waste throughout production and processing chain.These residuescontainhigh contentof bioactive compounds, but in generally not directly available, and for that reason is necessary to extract and characterize the feasible bioactive compounds(Santo et al., 2012).Therefore, the study of the wastes and by-products generated during pineapple production and post-harvest processing is relevant and interesting in order to valorize them and reduce their environmental impact.Pineapple (Ananas cosmosus) is a popular fruit, which grows in the tropics and sub-tropicsand belongs to the Bromeliaceae family. The fruit can be marketed to be natural or industrially processed, generating waste such as peels, stems, crowns and cylinder, which correspond to 35% of raw material processed (Erukainure et al., 2011).Frozen pineapple wastes were submitted to a milling and pressing processes, creating a pineapple juice and a solid semi-dried extract. Characterization of both parts comprised proteins, sugars, fibers, lipids and polyphenol contents. Additionally the total extraction yields were calculated.The solublefraction was fractionated by centrifuge tubes with cut-off of 50 KDa and after by cut-off of 3 KDa, and three fractions were obtained: above 50 KDa, between 50 and 3 KDa and below 3 KDa. Besides compositional analysis the fractionswere also evaluated concerning antioxidant activityassessed through ABTS colorimetric assay and by ORAC fluorometric assay. The fraction with MW between 50 and 3 KDa were constituted mainly by soluble proteins (proteases), such as bromelain, ananain and comosainand characterized byUreia ? gel electrophoresis. On the other hand, the proteolytic activity of bromelain and the others was accessed by a modified in vitro microplate assay using a model with different types of substrates (Hale et al., 2005). The insoluble part was submitted to hot aqueous extraction during 1 hour at 80 ºC with uniformstirring (100 rpm), promoting a hot solubilisation; the mixture was cooled and centrifuged (12000 g for 20 min).In the supernatant were present the soluble polysaccharides and in the pellet pineapple ligninocellulosic material. The soluble fraction was precipitated with 3 volumes of ethanol and evaluated the presence of the differentpolysaccharides. The solid fraction was re-dissolved and treated with commercial enzymes (cellulases, pectinases and hemicellulases). The solution was centrifuged andseparated by membranes with cut-off of50 and 3KDa, and the fractions were evaluated by SDS-PAGE, FPLC and HPLC method.Acknowledgements: The authors would like to thank to the FP7 project BiValBi - Biotechnologies to Valorise the regional Biodiversity in Latin America (Refª PIRSES-GA-2013-611493) and project PEst-OE/EQB/LA0016/2011, administrated by FCT.References:1.Erukainure, O. L., Ajiboye, J. A., Adejobi, R. O., Okafor, O. Y., Adenekan, S. O. (2011). Protective effect of pineapple (Ananas cosmosus) peels extract on alcohol-induced oxidative stress in brain tissues of male albino rats. Asian Pacific Journal of Tropical Disease 1(1):5-9.2.Santo, A. P. E., Cartolano, N. S., Silva, T. F., Soares, F. A. S. M., Gioielli, L. A., Perego, P., Converti, A., Oliveira, M. N. (2012). Fibers from fruit by-products enhance probiotic viability and fatty acid profile and increase CLA content in yoghurts. International Journal Food Microbiology 154(3):135-44.3.Hale, L. P., Greer, P. K., Trinh, C. T., James, C. L. (2005). Proteinase activity and stability of natural bromelain preparations. International Immunopharmacology 5: 783-793.

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