Abstract: Bighead carp bone protein was first pretreated by steam explosion or thermally, and then hydrolyzed with trypsin. The resultant hydrolysates were designated as SFBPH and HFBPH, respectively, and their free amino acids, volatile components and relative molecular mass distribution were analyzed and compared with each other. The results showed that the hydrolysis degree of SFBPH was higher than that of HFBPH. In SFBPH and HFBPH, small molecular components with molecular mass less than 1 000 Da accounted for 73.78% and 66.56% of the total amount, respectively. The total amount of free amino acids in SFBPH was 28.36 mg/mL, which was 1.3 times higher than that of HFBPH. In SFBPH and HFBPH, the amount of bitter amino acids accounted for 64.88% and 64.23% of the total amino acids, respectively. The overall taste of the two hydrolysates was dominated by bitterness. A total of 77 volatile components were detected by gas chromatography-mass spectrometry analysis, of which, 61 were detected in SFBPH, and 47 in HFBPH, with hydrocarbons and aldehydes being the most abundant ones.

Key words: steam explosion treatment; thermal treatment; fish bone; enzymatic hydrolysate; free amino acids; volatile components