+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Nutritional and Digestive Properties of Protein Isolates Extracted from the Muscle of the Common Carp Using pH‐Shift Processing


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          This study details the nutritional and digestive properties of protein isolates that are extracted from carp ( Cyprinus Carpio L.) muscle using pH shifting methods. Alkaline (ALPI) and acid (ACPI) protein isolates exhibit higher protein yields (87.6%, 76.3%, respectively). In addition to the high recovery of myofibrillar protein, a portion of the water‐soluble proteins is also recovered. The moisture contents of ACPI and ALPI are 85.5% and 88.5%, respectively, and the crude protein contents of these two fractions are 83.20% and 83.0%, respectively, both contents of which are higher than those for fresh muscle. Most part of the ash and fat are removed in the separation process. The protein isolation is also found to be lighter and whiter than the fresh muscle and there is no difference between amino acid content of protein isolation and that of fresh muscle. The maximum solubility of water washed surimi is 73.21%, while solubility of ACPI‐2 and ALPI‐2 (pH 7.0) are 66.67% and 62.08%, respectively. The digestibility of ALPI and ACPI is improved after being treated with chymotrypsin, which is about 7–8 times as that of fresh muscle. The results indicate that the protein isolates have better nutritional and digestive properties than the fresh muscle does in food processing.

          Practical Applications

          Common carp is a lower additional value fish that exists in large amount in China. This study investigates nutritional and digestive properties of protein from carp extracted by pH shifting methods. According to the obtained data in this study, pH shifting method is a good protein recovery method that can effectively remove bone spurs, skin, fat and other impurities. In addition, sarcoplasmic proteins can also be recovered. The nutritional properties of protein isolates of carp were suitable for supplementing as an ingredient for human consumption. The pH‐shift process greatly improves the protein digestibility. Therefore, there are broad application prospects of the protein isolation as protein ingredients in food industry.

          Related collections

          Most cited references5

          • Record: found
          • Abstract: not found
          • Article: not found

          Determination of serum proteins by means of the biuret reaction.

            • Record: found
            • Abstract: found
            • Article: not found

            Changes in conformation and subunit assembly of cod myosin at low and high pH and after subsequent refolding.

            Conformational and structural changes of cod myosin at pH 2.5 and 11 and after subsequent pH readjustment to pH 7.5 were studied. Results suggest that on acid unfolding, the myosin rod may fully dissociate due to electrostatic repulsion within the coiled coil, while it does not dissociate at alkaline pH. Both pHs led to significant conformational changes in the globular head fraction of the myosin heavy chains, suggesting that it takes on a molten globular configuration. A large part of the myosin light chains are lost on both pH treatments. On pH readjustment to neutrality, the heavy chains take on a structural form similar to the native state with the coiled-coil rod reassociating from acid pH while leaving the globular head less packed, more hydrophobic and structurally less stable. The irreversible change brought about in the globular head region leads to the failure of light chains to reassemble onto it, a drastic loss in ATPase activity, and more exposure of reactive thiol groups. The acid and alkali processes therefore lead to substantial changes in the globular part of the myosin molecule and perhaps more importantly to different molecular changes in myosin, depending on which pH treatment is employed.
              • Record: found
              • Abstract: found
              • Article: not found

              Protein isolation from gutted herring (Clupea harengus) using pH-shift processes.

              Herring ( Clupea harengus ) and other pelagic fish species are mainly used for fish meal and oil production and not for human consumption. In this study, acid pH-shift processing and alkaline pH-shift processing were used to isolate proteins from whole gutted herring with the aim to investigate the potential use of herring proteins as a food ingredient. The acid and alkaline processes gave rise to similar protein yields, 59.3 and 57.3%. The protein isolates from both processes had a significantly (p 80% for both processes, with a trend (p = 0.07) toward higher removal during the alkaline process. Also, Ca and Mg removal was significantly (p < 0.05) higher during the alkaline process. The isolated proteins from the acid process contained myosin degradation products and had a lower salt solubility than proteins from the alkaline process. Both protein isolates had an amino acid profile meeting the recommendations for adults according to FAO/WHO/UNU and could produce a surimi gel of medium strength. The results show that pH-shift processing could be a valuable method for the production of functional food proteins from gutted herring.

                Author and article information

                J Food Process Preserv
                J Food Process Preserv
                Journal of Food Processing and Preservation
                John Wiley and Sons Inc. (Hoboken )
                29 April 2016
                February 2017
                : 41
                : 1 ( doiID: 10.1111/jfpp.2017.41.issue-1 )
                [ 1 ] College of Food Science and EngineeringDalian Ocean University Dalian 116023 LiaoningChina
                [ 2 ] Faculty of FisheriesKagoshima University Kagoshima 890‐0056Japan
                Author notes
                [*] [* ]Corresponding author. TEL/FAX: + 86‐411‐8476‐3552; EMAIL: ljunrong@ 123456yahoo.com
                © 2016 The Authors. Journal of Food Processing and Preservation published by Wiley Periodicals, Inc.

                This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.

                Page count
                Figures: 6, Tables: 3, Pages: 9, Words: 5294
                Funded by: National Natural Science Foundation of China
                Original Article
                Original Articles
                Custom metadata
                February 2017
                Converter:WILEY_ML3GV2_TO_NLMPMC version:5.0.5 mode:remove_FC converted:08.02.2017


                Comment on this article