Foodomics reveals altered lipid and protein profiles of Antarctic krill (Euphausia superba) under different processing

Drying processing is an indispensable procedure for the application of krill. Different drying methods usually offer significant influence on the physicochemical properties of foodstuff. This study investigated the effects of freeze and hot-air drying approaches on krill using lipidomics and proteomics. Multivariate analysis indicated the dramatic differences between freeze dried and hot-air dried krill. A total of 276 lipids were observed to be changed, including phosphatidylcholines (PC), triacylglycerols (TG) as well as fatty acids (FA) and their conjugates. Interestingly, several long-chain polyunsaturated phospholipids, such as PC (20:5_22:6), PC (20:5_20:5) and PE (16:0_22:6) displayed higher contents in hot-air dried krill, suggesting that method was beneficial to the high-quality krill oil extraction. On the other hand, the levels of 13 proteins in hot-air dried krill were noted to be higher, whereas other 101 proteins were found to be higher in freeze dried krill. These results indicated that hot-air drying processing reserved more phospholipids in krill oil, but degraded lots of krill tissue proteins. The freeze drying maintained more proteins in tissue, increasing the risk of deterioration for long-term storge. Taken together, this comprehensive analysis provided novel insights into the processing of krill to facilitate the utilization of krill resource.