Browsing by Author "Paulo, Maria"
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- Assessment of traditional mayonnaise enriched with Aurantiochytrium sp. extractPublication . Pinheiro, Joaquina; Garcia, Adriana; Paulo, Maria; Coutinho, Joana; Baptista, Teresa; Bernardino, Susana M.; Tecelão, Carla; Gil, Maria M.; Lemos, Marco F.Mayonnaise, a food product widely consumed since the 1900s, traditionally prepared from a mixture of oil, egg yolk and vinegar, has a reduced shelf-life primarily due to lipid oxidation (Kwon et al., 2015). The addition of synthetic antioxidants like BHT (butylated hydroxytoluene), BHA (butylated hydroxyl anisole), and EDTA (ethylenediaminetetraacetic acid) has been used to control this problem (Gray, 1978). However, these synthetic antioxidants showed several disadvantages such as the easily decomposition at higher temperatures, and an increased health risk for chronic consumers (Martinez-Tome et al., 2001). Natural antioxidants, derived from marine algae, show great potential for improving oxidative stability, extending the shelf-life of stored food products with additional health-promoting benefits (Hermund et al., 2015). Since 2004, the DHA-rich oil derived from the microalgae Aurantiochytrium sp. has been recognized as safe, available for food use and for dietary supplements. In general, Aurantiochytrium sp. became a popular source of protein-rich biomass and of valuable compounds like pigments, antioxidants and essential fatty acids. The potential of heterotrophic microalgae Aurantiochytrium sp. as a source of functional ingredient applied in mayonnaise product has not been evaluated yet. The aim of this study was to evaluate the quality of mayonnaise enriched with Aurantiochytrium extract by colour (L*, a*, b*, and ºh), texture (hardness, adhesiveness, resilience, cohesion, springiness, gumminess, and chewiness) and antioxidant capacity (DPPH and total phenolics content). The mayonnaise without extract was used as control sample. Colour results indicated that the luminosity of mayonnaise enriched with extract increased and the a* and b* colour parameters decreased, promoting a colour enhancement. Also, with the addition of Aurantiochytrium extract, a decrease in all texture attributes obtained by TPA profile test, with exception of cohesion and springiness, was observed. A correlation between antioxidant activity and total phenolics content was denoted, in all samples. The high antioxidant capacity can be related to high radical scavenging activity, high total phenolic content, and high carotenoid content of the extract. This study demonstrates that Aurantiochytrium sp extracts have the potential to be used as a nutraceutical/functional ingredient in mayonnaise, a product widely consumed by different age groups.
- Bioactivity screening of Aurantiochytrium sp. for antioxidant activitiesPublication . Pinheiro, Joaquina; Garcia, Adriana; Paulo, Maria; Coutinho, Joana; Baptista, Teresa M.; Bernardino, Susana M.; Tecelão, Carla; Gil, Maria M.; Lemos, Marco F.L.Aurantiochytrium sp. is a heterotrophic microalgae that, in certain growth conditions, besides producing significant amounts of squalene, may potentially produce other bioactive compounds with high value and commercial interest such as docosahexaenoic acid (DHA), carotenoids, among others. Antioxidant compounds, naturally occurring in microalgae sources, have been identified as free radical or active oxygen scavengers, with beneficial effects on oxidation and oxidative damage inhibition in human body and foods. Several in vitro methodologies have been proposed to evaluate the antioxidant capacity, such as free radicals: 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), and reactive species including hydrogen peroxide (H2O2), singlet oxygen (O2), and superoxide anion (O2-) (Balboa et al., 2013). The main objective of the present study was to evaluate the antioxidant activity of aqueous and ethanolic extracts of Aurantiochytrium sp., by means of different methodologies: reducing and scavenging activity by total phenolics content (TPC, Singleton & Rossi, 1965), DPPH (Custódio et al., 2012), and oxygen radical absorbance capacity (ORAC, Dávalos et al., 2004). The obtained results indicated that the microalgae Aurantiochytrium sp. is rich in antioxidant compounds, by reducing activity through total phenolics and DPPH, as well as scavenging activity by ORAC. Moreover, it is evident the higher selectivity of ethanol as solvent for the extraction of antioxidants compounds. The potential of this microalgae biomass as a good, natural and sustainable source for use as a functional food ingredient is evident, representing an opportunity with additional benefits due to the antioxidant role in diseases prevention and treatment.