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Court-Saint-Étienne, Belgium

Goiris K.,Catholic University of Leuven | Goiris K.,Leuven Food Science and Nutrition Research Center oe | Goiris K.,Research Unit Aquatic Biology | De Vreese P.,Catholic University of Leuven | And 3 more authors.
Journal of Agricultural and Food Chemistry | Year: 2012

Currently, microalgae draw much attention as a promising source of natural antioxidants to replace synthetic antioxidants for food applications. In this paper, the use of voltammetric techniques as a fast alternative for chemical assays to determine the antioxidant power of microalgal biomass is discussed. It was found that antioxidant activities determined by square wave voltammetry correlate well with the results from other established antioxidant assays, such as Trolox equivalent antioxidant capacity (R2 = 0.737), ferric reducing antioxidant potential (R2 = 0.729), and AAPH-induced oxidation of linoleic acid (R2 = 0.566). Besides yielding quantitative data on the antioxidant activity, square wave voltammetry provides additional information on the antioxidant profile of microalgal biomass as the peak potentials of antioxidant components are determined. Consequently, square wave voltammetry can be used as a tool for optimizing the extraction processes to recover antioxidant components from microalgae. © 2012 American Chemical Society.

Goiris K.,Catholic University of Leuven | Goiris K.,Leuven Food Science and Nutrition Research Center oe | Goiris K.,Research Unit Aquatic Biology | Muylaert K.,Research Unit Aquatic Biology | And 5 more authors.
Journal of Applied Phycology | Year: 2012

In the past decades, food scientists have been searching for natural alternatives to replace synthetic antioxidants. In order to evaluate the potential of microalgae as new source of safe antioxidants, 32 microalgal biomass samples were screened for their antioxidant capacity using three antioxidant assays, and both total phenolic content and carotenoid content were measured. Microalgae were extracted using a one-step extraction with ethanol/water, and alternatively, a three-step fractionation procedure using successively hexane, ethyl acetate, and water. Antioxidant activity of the extracts varied strongly between species and further depended on growth conditions and the solvent used for extraction. It was found that industrially cultivated samples of Tetraselmis suecica, Botryococcus braunii, Neochloris oleoabundans, Isochrysis sp., Chlorella vulgaris, and Phaeodactylum tricornutum possessed the highest antioxidant capacities in this study and thus could be a potential new source of natural antioxidants. The results from the different types of extracts clearly indicated that next to the well-studied carotenoids, phenolic compounds also contribute significantly to the antioxidant capacity of microalgae. © 2012 Springer Science+Business Media B.V.

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