Effect of pre-treatments on yield and properties of lipid extracted from cephalothorax of Pacific white shrimp (Litopenaeus vannamei) by ultrasonic assisted process

Abstract

Impacts of different pre-treatments of cephalothorax from Pacific white shrimp before ultrasound assisted extraction (UAE) on yield and characteristics of lipids were studied. Autolysis at 50 °C for 3 h in the absence and presence of 0.1% tannic acid (TA), a lipase inhibitor, was implemented. Pre-heating of cephalothorax containing 0.1% TA at 95 °C for different times (15–45 min) was also carried out. When UAE was used to extract the lipids at the ultrasonic amplitude of 80% for 25 min in continuous mode, samples with pre-heating rendered the highest lipid yield (13.3g-14.1 g/100 g sample). Pre-heating along with TA addition resulted in suppression of lipid oxidation as evidenced by decrease in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Free fatty acid (FFA) content was also found to be lower, whereas the control (without pre-treatment) had higher FFA. Fourier transform infrared (FTIR) spectra confirmed lower oxidation in lipid from pre-heated samples added with TA. Lipid contained astaxanthin, astaxanthin monoester, astaxanthin diester, canthaxanthin and β-carotene. Overall, the combination of pre-heating and addition of TA was a promising means to increase the yield and maintain the quality of lipid from cephalothorax using UAE.