The extraction yield and TCC values for the cooked, dried and milled raw material (pre-treatment), obtained by means of the different extraction techniques are presented in Table 2, together with the solvent polarity index, the solvent/solid ratio and the extraction time. Comparing the conventional method of carotenoid extraction (Table 1 ) with other extraction techniques (Table 2) we observed that only the Soxhlet with ethanol method presented an extraction yield much higher than the conventional method, with values of 68 ± 6% and 23.5 ± 0.5%, respectively. Alternatively, when we compare the results in terms of TCC values, the data from Table 2 indicate that several procedures were more efficient in obtaining
carotenoid compounds, with values up to 253 ± 7 g g−extract1 for the maceration with acetone, compared to the value of 29.2 ± 0.3 g g−extract1 for the conventional result (Table 1 ). The conventional method (Table 1 ) requires high amount of solvent and 24 h of extraction time to obtain yield and carotenoid values inferior to the ones reached by other non conventional extraction procedures (maceration with hexane, hexane:isopropanol, acetone, ethanol; Soxhlet with: hexane, hexane:isopropanol, isopropanol, acetone; and ultrasound with ethanol – Table 2). The results from Table 2
show the importance of the optimization of the extraction techniques to achieve the maximum TCC value. Furthermore, because of the considerable quality of the extracts (high TCC values) obtained by the extraction methods listed in Table 2, we suggest that pink shrimp residue is a suitable raw material to obtain valuable byproducts.