Abstract
Huge amount of shrimp waste are produced annually in Denmark. This is a natural source of carotenoids and particularly astaxanthin (ASX). In this study, supercritical fluid extraction (SCFE) was used as a green technique and the effects of pressure (200, 300, and 400 bar), temperature (35, 45, and 55 °C), and three green co-solvents (ethanol (EtOH), sunflower oil (SF), and its methyl ester) on ASX yield and total extract yield were investigated. The results showed that high temperature and pressure had a positive influence on ASX yield and total extract yield. Conducting the process at 400 bars and a temperature of 55 °C resulted in ASX yield of about 23 mg/ kg of dried shrimp waste (DW). This amount is comparable to the ASX extraction yield obtained by the conventional organic solvents; however, the total extract yield was significantly lower. Adding 5 % EtOH increased the ASX concentration in the extract almost twice, while the total extract yield did not changed significantly. In addition, by using SF and its methyl ester as alternative co-solvents ASX yields of about 25 and 35 mg/ kg of DW, respectively, were achieved.
