Optimisation of supercritical fluid extraction of astaxanthin from Penaeus monodon waste using ethanol-modified carbon dioxide

Some studies demonstrated that astaxanthin surpasses the antioxidant benefits of beta-carotene,zeaxanthin,canthaxanthin,vitamin c,and vitamin e. penaeus monodon (tiger shrimp) is one of the most valuable traded crustacean products in which astaxanthin can be found in its by-products. the extraction of thermolabile compound like carotenoids at lower temperatures through supercritical carbon dioxide (sc-co2) can reduce the potential isomerization and degradation of the extraction product. in this study,astaxanthin had been extracted using sc-co2 with 15% (v/v) ethanol as an entrainer and the recovered astaxanthin was analyzed using high performance liquid chromatography (hplc). a central composite design (ccd) was employed to study the effect of three sc-co2 parameters namely temperature (x1) from 40 to 80°c,pressure (x2) from 150 to 250 bar and extraction flow rate (x3) from 1 to 3 ml/min on the astaxanthin complex yield,(y1) and free astaxanthin content,(y2). the nonlinear regression equations were significantly (p<0.05) fitted for both responses with high r2 (>0.9261),which had no indication of lack of fit. the results indicated that a combined set of values of temperature (56.88°c),pressure (215.68 bar) and extraction flow rate (1.89 ml/min) was predicted to provide the optimum region in terms of astaxanthin complex yield,(58.50 ± 2.62 µg/g) and free astaxanthin content (12.20 ± 4.16 µg/g) studied. © school of engineering,taylor’s university.