ねり製品の保水性に関する研究 Ｖ すり身とその加熱ゲルの保水性に及ぼすｐＨと食塩濃度の影響

Abstract

Water in Alaska pollack surimi and its gel was categorized into types Ip-A (“free water”), Ip-B (loose “entrapped water”), and IIp (tight “entrapped water”) plus IIIp (“immobilized water”) by our press method. The maximal Ip-A and the minimal Ip-B and IIP plus IIIp in amounts were estimated in both non-salt-ground and salt-ground surimi at a pH of about 5; that is, the water holding capacity (WHC) of surimi was minimal at this pH. The amount of Ip-A in salt-ground surimi with pHs below 5 was larger than in the non-salt-ground one. With the increase of pHs above 5, WHC of surimi markedly increased and the amount of Ip-A decreased more in the salt-ground surimi than in the non-salt-ground material. The amount of Ip-A in surimi at pH7, near the ordinary pH value of surimi for kamaboko, reached a minimum after the addi-tion of 2-3% NaCl.After heating surimi with pHs between 5 and 9 at 90°C for 40 min, amounts of Ip-A were also less in salt-ground surimi gels than in non-salt-ground ones. Especially small amounts of Ip-A and large amounts of Ip-B were determined in the salt-ground surimi gel at pH 7, near the ordinary pH value of kamaboko with a high WHC. The salt-ground surimi gel with large amount of Ip-A and the low gel-strength was significantly saltier than that with a small amount of Ip-A and the high gel-strength.