RESUMEN
The process-related physicochemical, digestive and rheological properties of protein prepared by subcritical dimethyl ether extraction (SDEE) were comprehensively investigated and compared with those obtained by pH-shift, to study the industrial potential of SDEE. Two different materials from tuna (meat and liver) were studied in parallel, and SDEE had similar effects on the proteins in them. The protein component was almost unchanged before and after SDEE, while the content of water-soluble protein and alkali-soluble protein was substantially reduced and increased after pH-shift, respectively. We also found that SDEE had superior ability to pH-shift to conserve light metals, remove lipids and heavy metals, and maintain protein structure. Furthermore, SDEE-produced protein powders were easier for humans to digest, and their gelation and emulsification were also superior to those prepared by pH-shift. The aforementioned results suggest that SDEE can remove more impurities, and the obtained protein has outstanding potential in industrial applications.