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The fish skin gelatin hydrolysates were produced using a continuous two-stage membrane (MWCO 10,000, MWCO 5,000) reactor, and molecular weights. amino acids and functional properties of the hydrolysates were investigated. The major molecular weights distribution of the major fractions were 8∼10 KDa and 4.5∼6.5 KDa in the 1st-step hydrolysates, 2∼6 KDa and 0.5∼2 KDa in the 2nd-step hydrolysates. Among the amino acids in the hydrolysates, glycine, proline, serine, alanine, hydroxyproline, glutamic acid and aspartic acid having sweet taste were responsible for 68∼72% of the total amino acids. But valine, methionine, isoleucine, leucine, phenylalanine and histidine having a bitter taste were only 23∼25%. Taste evaluations show that the gelatin hydrolysates have a brothy and sweet taste, 2nd-step hydrolysate have more a favorable taste than 1st-step hydrolysate. The hydrolysates were completely soluble and clear over the entire pH range. Moisture sorption at intermediate water activities of the 2nd-step hydrolysate was much higher than the unmodified fish skin gelatin, but foaming and emulsification properties were poor. Buffer capacity of the 2nd-step hydrolysate was higher thin the fish skin gelatin and 1st-step hydrolysate, while viscosities of the hydrolysates were lower than the fish skin gelatin.
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