Comparative Study of Bioactive Lipid Extraction from Squid (Doryteuthis gahi) by-Products by Green Solvents

Abstract

A novel approach of bioactive lipid extraction by different green solvents was carried out on squid (Doryteuthis gahi) by-products. By-products (viscera, heads, skin, tails, etc.), considered as a single product, were subjected to the following solvent systems: ethanol, acetone, ethyl acetate, 1/1 ethanol/acetone, 1/1 ethanol/ethyl acetate, and 1/1 acetone/ethyl acetate. Analyses carried out included lipid yield, lipid class content, and fatty acid (FA) composition. Results were compared to the lipid extract obtained by the traditional procedure (1/1 chloroform/methanol). Lipid yields obtained by green solvents led to a 33.4–73.2% recovery compared to traditional extraction; the highest values (p < 0.05) were obtained by ethanol-containing systems. Compared to the traditional procedure, ethanol systems showed an 85.8–90.3% recovery of phospholipid compounds and no differences (p > 0.05) in the ω3/ω6 ratio. Green-extracting systems led to higher average values for eicosapentaenoic acid content (15.66–18.56 g·100 g−1 total FAs) and polyene index (1.93–3.29) than chloroform/methanol extraction; differences were significant (p < 0.05) for systems including acetone and ethyl acetate. No differences (p > 0.05) were detected for docosahexaenoic acid content between the traditional procedure and green systems, with all values being included in the 31.12–32.61 g·100 g−1 total FA range. The suitability of EtOH-containing green systems for extraction of bioactive lipid compounds from squid by-products was concluded.

Optimised extraction of phospholipids and omega‐3 fatty acids from Patagonian squid waste with low‐toxicity solvents

“…This higher concentration resulting from ethanol‐extracting mixtures can be explained based on a lower extraction of relatively non‐polar lipid classes like waxes or TAGs so that a relative increase of polar lipid classes like PLs in the total lipid fraction can be produced. In agreement with the current results, an increasing PL value was previously obtained by employing the following solvent sequence: acetone < ethyl acetate < ethanol during extraction of waste of the present squid species (Aubourg et al ., 2022b). This solvent sequence agrees with an increasing polarity of solvents so that a more abundant extraction of polar lipids like PL compounds would be produced.…”

“…21%–22%) during the extraction of PL compounds from krill ( Euphausia superba ) (Gigliotti et al ., 2011). Recently, a decrease of the PL content in the ethanol/acetone (1:1, v/v) lipid extract obtained from Patagonian squid waste was observed by increasing the number of extractions (Aubourg et al ., 2023); this decrease was explained on the basis of an increased extraction of less polar lipid classes such as TAGs, waxes, cholesterol esters, etc .…”

“…Based on the profile obtained, DHA, C16:0 and EPA showed to be the major FAs according to previous research regarding the waste substrate of the current species (Aubourg et al ., 2021, 2023). A similar profile was also detected in different kinds of by‐products resulting from cephalopod species such as gonad and liver of arrow squid ( Loligo bleekeri ) (Hayashi, 1996), digestive gland and ovary of common octopus ( Octopus vulgaris ) (Sieiro et al ., 2006) and squid ( Loligo formasana ) ovary (Singh et al ., 2017).…”

“…Based on the previous study carried out in our laboratory (Aubourg et al, 2022b), lyophilisation of waste was found necessary to facilitate the lipid extraction with the present solvents and, therefore, increase the lipid yield. In general, the need for moisture elimination has been reported in related research including eco-friendly solvents as the present ones (Gigliotti et al, 2011;Jiménez Callej ón et al, 2020).…”

“…Previous research has also focused on the extraction of lipid compounds from Patagonian squid waste by eco-friendly methods. Thus, the convenience of low-toxicity solvents (ethanol, acetone and ethyl acetate) was checked in preliminary trials (Aubourg et al, 2022b(Aubourg et al, , 2023. Additionally, optimisation of the total lipid and tocopherol yields was studied (Rodrıǵuez et al, 2023).…”