Phytochemical analysis and biological activity of Lupinus luteus seeds extracts obtained by supercritical fluid extraction

The article describes a possible application of Sc-CO2 extraction for isolation of polyphenols from germinated lupin seeds. Efficiency of germination duration was valorized, and the obtained results suggest that six-day-long germination process provides samples with the highest polyphenolic yield. Optimization of extraction parameters was done by using response surface methodology (RSM). Extracts obtained under optimal extraction conditions (73 degrees C, 147 bar, 16.1% of co-solvent) were characterized in terms of their chemical composition and biological activity. The yield of extraction was 3.25% while total phenolic content was 14.56 mg GAE/g. HPLC-ESI-MS/ MS analysis confirmed the presence of different polyphenolic compounds in which apigenin and fisetin were proven to be dominant compounds. The GC-MS analysis revealed that the obtained extract is also rich in fatty acids, phytosterols and lupeol. Further tests determined the antioxidant, antiradical, antimicrobial and cytotoxic potential of samples. Fluorescence investigation was used to visualize the effect of Lupinus luteus extract on viability of bacterial cells. In addition, it has been shown that the extract tested in anti-bacterial concentrations does not exhibit cytotoxicity.