Simultaneous Extraction of Oil, Protein, and Polysaccharide From Antarctic Krill Using Three‐Phase Partitioning

ABSTRACT Antarctic krill, known for its abundant reserves and high nutritional content, represents a valuable resource for humanity. The purpose of this study was to explore the feasibility of simultaneous extraction of Antarctic krill oil (AKO), Antarctic krill protein (AKP), and Antarctic krill polysaccharides (AKS) from krill by three‐phase partitioning (TPP) method and the optimal extraction conditions of AKO. The fatty acid composition of AKO and the structural characteristics of AKP and AKS were analyzed and compared with the experimental results obtained by other methods. Response surface optimization results showed that under the conditions of 50% (w/v) (NH 4 ) 2 SO 4 , 1:1 (v/v) ratio of slurry to t ‐butanol, pH 5.10, extraction temperature 50°C, and extraction time 2 h, the optimal extraction yield of AKO (EY AKO ) was 17.65%. Under these conditions, the extraction yields of AKP (EY AKP ) and AKS (EY AKS ) were 9.44% and 0.25%, respectively. Additionally, AKO extracted by TPP method was rich in more polyunsaturated fatty acids (PUFAs) than traditional methods, especially n ‐3 PUFAs. The structure of AKP was analyzed by Fourier transform infrared (FTIR) and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), showing that it is not damaged. The FTIR results show that AKS has the characteristic structure of homologous marine sulfated polysaccharides, indicating it is maybe a sulfated polysaccharide. This study shows that it is feasible and efficient to extract AKO, AKP, and AKS simultaneously by TPP methods. Our research provides a new way to extract nutrients from Antarctic krill. Practical Applications : This study facilitates the comprehensive utilization of the substantial Antarctic krill resource, significantly enhancing their economic value and utilization efficiency. The optimized TPP method yields AKO with both high extraction efficiency and a rich content of n ‐3 PUFAs. These two advantages combine to enable its use in high‐end AKO production while simultaneously laying the technical groundwork for valorizing AKP and AKS as main products, thereby providing more options for the Antarctic krill industry. It also serves as a valuable reference for researchers engaged in the comprehensive utilization of other marine biological resources. The preliminary structural analyses (FTIR, SDS–PAGE) of AKP and AKS provide essential preliminary data to support deeper investigation into these molecules and lay a scientific foundation for the subsequent development and application of AKP and AKS.