Haematococcus pluvialis Flotow is a microalga used as a nutraceutical, due to its high content in bioactive compounds, mainly carotenoids, in which astaxanthin stands out [1]. Furthermore, H. pluvialis has shown a high antioxidant potential and combined to its intense red colour, this microalga could have a dual functionality, as a colourant, and a bioactive ingredient [2]. The process to obtain this ingredient involves several transformation steps, such as lyophilization and saponification, that raise the development costs, to obtain free astaxanthin, that paradoxically presents greater instability and solubility than its esterified counterpart [3]. Thus, this work provides an alternative approach for the application of red, astaxanthin-rich, H. pluvialis wet paste as a partial substitute for wheat flour (7% and 13% w/w) in the preparation of filloas (Galician pancakes), a typical dessert from the northwestern region of the Iberian Peninsula. To evaluate its power as a natural pigment, the stability of colour over time (3, 6 and 9 days) was measured in contrast to a commercial colourant. At the same time, its physicochemical properties were measured, such as the microbiological profile to determine its functionality as a food preservative. As a result, a redness stability (a*), 8% higher than the commercial colourant, was obtained for the maximum concentration of H. pluvialis analysed. The texture showed a significant response (p<0.02), improving its properties as the concentration of the microalga increased, showing during the first 6 days a tenacity of 3.23 N and an extensibility of 15.10 mm, which represents a 52 and 19% improvement respectively, in relation to the control group. In turn, an enrichment of carotenoids, fatty acids, and phenolic compounds in combination with a potential moderator of microbiological degradation by this unicellular organism gives added value to this food matrix.

References

1. Castillo, A.; Pereira, S.; Otero, A.; Fiol, S.; Garcia-Jares, C.; Lores, M. Matrix Solid-Phase Dispersion as a Greener Alternative to Obtain Bioactive Extracts from: Haematococcus pluvialis. Characterization by UHPLC-QToF. RSC Advances 2020, 10, 27995–28006, doi:10.1039/d0ra04378h.

2. Udayan, A.; Arumugam, M.; Pandey, A. Nutraceuticals from Algae and Cyanobacteria. Algal Green Chemistry: Recent Progress in Biotechnology 2017, 65–89, doi:10.1016/B978-0-444-63784-0.00004-7.

3. Rodríguez-Sifuentes, L.; Marszalek, J.E.; Hernández-Carbajal, G.; Chuck-Hernández, C. Importance of Downstream Processing of Natural Astaxanthin for Pharmaceutical Application. Frontiers in Chemical Engineering 2021, 0, 29, doi:10.3389/FCENG.2020.601483.

Acknowledgements

This research was funded by project ED431 2020/06 (Galician Competitive Research Groups Xunta de Galicia). This work was supported by project EQC2018-005011-P (Ministry of Science, Innovation and Universities, Spain). All these programmes are co-funded by FEDER (EU). The authors are also grateful to Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); to FCT for S. Heleno (CEECIND/03040/2017) and L. Barros contracts through the individual and institutional scientific employment program-contract, respectively.