Eco-Innovative Approach for the Extraction of Arthrospira platensis to Enhance Antioxidants and Nutritional Value

The microalgae Spirulina (Arthrospira platensis) is cultivated on a large scale, with a global production of approximately 18,000 tons year-1. Its high nutritional content and health-promoting properties have led to its establishment as a key ingredient in dietary supplements. However, the efficient extraction of its bioactive compounds remains challenging. The present study aims to develop an eco-innovative method to enhance spirulina’s antioxidant and nutritional values. The extraction protocol involved a maceration step in phosphate-buffered saline (PBS, pH 7.4) at 5 °C for 48 hours, followed by ultrasound-assisted extraction (UAE) at 400 W, 30 kHz, 30 cycles/min (with cycles of 1 sec. on/ off, for a total of six extraction cycles). This method substantially improved APC (+41.41%) and PE (+81.42%) yield. The lipid fraction exhibited an increase of 20.29%, including carotenoids (+30.84%), total fatty acids (60.48%), and polyphenols (+65.99%), allowing an increased antioxidant activity (+42.95%). On the contrary, proteins (–16.65%), carbohydrates (-18.84%), and PC (-0.77%) showed decreased recovery rates. This study provides a promising approach for extracting high-value compounds from spirulina, supporting its potential applications in the dietary supplement sector.