Haematococcus pluvialis is the richest biological source of astaxanthin under unfavorable growing conditions. Many reports have discussed the optimal astaxanthin extraction methods. Free-astaxanthin could be still hindered by microalgae extracts composition or by prolonged extraction times. In this study we evaluated the effect of enzymolysis and saponification deesterification processes of astaxanthin and its carotenoid precursors under high irradiance and nitrogen deprivation stress time conditions. Results showed that cholesterol esterase facilitated astaxanthin deesterification (975.65 μg mg−1 DW) while saponification positively affected zeaxanthin (1038.68 μg mg−1 DW).