Abstract: Protein hydrolysate from visceral waste proteins of sea cucumber was prepared by hydrolysis with neutral protease, followed by ultrafiltration and freeze drying. The protein content in the protein hydrolysate was 73.02%, which was composed mainly of small peptides. The results of high performance liquid chromatography analysis showed that the relative molecular weight of the hydrolysate was mainly distributed in the range of 187–998 D, accounting for 77.9% of the total peak area. In vitro antioxidant experiments showed that the protein hydrolysate had significant antioxidant activity. The hydrolysate at various dosages (200, 400 and 800 mg/(kg·d)) could significantly reduce the malonaldehyde content in mouse livers, and also increase the activity of superoxide dismutase, and glutathione contents (P < 0.01). The results illustrated that the hydrolysate could effectively restore antioxidant indexes. The experiments of antifatigue activity proved that the hydrolysate had high antifatigue activity. All three dosages of the hydrolysate could significantly increase the exhaustive swimming time and liver glycogen contents of mice, and reduce the contents of lactic acid and urea nitrogen in the serum of mice (P < 0.01).

Key words: sea cucumber viscera, enzymatic hydrolysis, antioxidant, antifatigue