Process development of cholesterol removed Pacific white shrimp lipid enriched with astaxanthin using silica column

Abstract

This study used silica column to eliminate cholesterol and to fractionate astaxanthin for production of cholesterol free shrimp lipid rich in astaxanthin. Polar fraction was loaded onto silica gel column and eluted using hexane/ acetone mixture with different ratios consecutively. The first fraction (F1) was obtained after elution with hexane. For fraction 2 and 3 (F2, F3), hexane/ acetone mixture (98: 2) and (96: 4) were used, respectively. Both fractions were rich in cholesterol, while F4 eluted with hexane/ acetone mixture (94: 6) consisted of pigments and fatty acid conjugates. Astaxanthin was found in F5, where hexane/ acetone mixture (98:2) was used for elution and it constituted 30% of total components. Cholesterol containing fractions (F2 and F3) accounting for 26% were removed and other fractions were combined with non-polar lipid. Fraction F5 was further injected into HPLC to separate astaxanthin peak from other compounds. The collected astaxanthin containing peak had 87% purity. LCMS result showed the presence of wax esters along with cholesterol in F2 and F3 and fatty acid conjugates along with astaxanthin were found in F5. Lowered cholesterol fraction had negligible wax esters. Overall, the developed method could be used for production of cholesterol removed shrimp oil.