Abstract:

Proteins were extracted from the homogenized mantle of scallop (Patinopecten yessoensis) by pH adjustment inthe range of 1.5－12.0 with an interval of 0.5 unit using 2 mol/L HCl or 2 mol/L NaOH. The pH-dependent solubility andrecovery by isoelectric point precipitation of scallop mantle proteins were investigated. The acid-extractable and alkaliextractableproteins from scallop mantle were analyzed for physiochemical and functional properties. The results showed thatscallop mantle proteins had an isoelectric point in the range of pH 4.5－5.0 and exhibited a significant correlation betweenrecovery and solubility (R2 = 0.998 7). The recovery rates of alkali-soluble and acid-soluble proteins were 90.75% and83.31%, respectively. SDS-PAGE analysis suggested that most protein components could be effectively recovered by acid oralkali extraction. Both acid-soluble and alkali-soluble proteins were of high purity degree (80.21% and 84.28%, respectively)and contained significantly reduced amounts of fat than the starting raw material (1.02% and 0.80% vs. 3.55%). Furthermore,the whiteness scores of acid-soluble and alkali-soluble proteins were respectively 66.49 and 64.91, which were considerablyhigher than that (58.40) of the starting raw material. Neither of the protein isolates was significantly superior to soybean proteinisolate in terms of water-holding capacity, oil-holding capacity, foaming capacity, and emulsifying activity index.

Key words: Patinopecten yessoensis, mantle, protein isolate, functional properties