Microalgae biomass incorporation in salted cookies (“crackers”) increases their functional properties

In a previous work [1], microalgae sweet cookies were developed, but microalgae savoury foods might be more easily accepted due to their characteristic marine flavour. This study evaluated salted cookies (“crackers”) with 2% and 6% (w/w) of Arthrospira platensis F&M-C256, Chlorella vulgaris Allma, Tetraselmis suecica F&M-M33 and Phaeodactylum tricornutum F&M-M40 biomass, in terms of physicochemical properties, in vitro digestibility (IVD) and radical scavenging activity (RSA). Microalgae crackers showed significantly higher (p<0.05) protein content than the control (9.8% dw), with the highest values (>14% dw) for 6% A. platensis and C. vulgaris. The highest total dietary fiber (6.7% dw) was found for 6% A. platensis cracker while the control had 5.0% (dw). The addition of algae did not significantly increase the salt content in relation to the control (1.9% dw), except for 6% T. suecica (2.6% dw). Microalgae crackers showed high IVD, with values ranging from 81.9% to 85.8%, with the highest value for A. platensis. These values are within the IVD range of commercial salted crackers. The highest RSAs (24.4-24.6%, which corresponds to 0.25 mg/galga of vitamin C equivalent antioxidant capacity) were found for A. platensis and P. tricornutum both at 6% incorporation. Total phenolics in microalgae crackers ranged from 1.1 to 2.4 mg of gallic acid equivalent per g of algal biomass, with the highest value for T. suecica 6%.