• Treatment with hot-compressed or subcritical water is an attractive process for converting food waste into valuable materials. Water is an environmentally acceptable solvent and is cost effective; thus, hot-compressed water has recently received attention as a medium for resource recovery from waste. We chose fish gelatin as a model of marine food waste (especially fish skin fraction), and we determined the optimum conditions for the degradation of fish gelatin with hot-compressed water between 160 and 240 °C at 2 MPa. These conditions were optimized in terms of maximizing the concentrations of specific degradation products, such as peptides, and ACE inhibitory.

The disposal of fish waste has become a serious problem in marine food industries because approximately half of the fish mass, including the skin, bones, entrails, and some meat. The feasibility of converting organic waste by hot-compressed water (subcritical water treatment) into useful resources has been demonstrated together with Industry.

• hot-compressed water
• resource recovery from waste