89B-27 |
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J. PARK1, J. W. Park1, and Y. J. Choi2. (1) Food Science and Technology & OSU Seafood Laboratory, Oregon State Univ., 2001 Marine Drive #253, Astoria, OR 97103, (2) Division of Marine Bioscience, Gyeongsang National Univ., Tong Yeong, South Korea Myoglobin is washed away during conventional surimi processing. There are two divided opinions about the effect of myoglobin on the gel forming ability of myofibrillar proteins (surimi): one side thinks it is negative, while the other side positive. With the application of a new method of fish protein isolation that retains myoglobin, there is a great need to refocus on the role of sarcoplasmic proteins such as myoglobin on the gelation properties of surimi. Our objectives were to determine the effect of myoglobin addition to the surimi gel quality and to understand the role in the gelation mechanism of myofibrillar proteins. Myoglobin was extracted from sardine (Sardinops sagax) fillet after homogenizing with 0.01 N sodium phosphate buffer (pH 6.3. The homogenate was centrifuged at 7000 rpm for 20 min and then the supernatant was treated with saturated ammonium persulfate. Precipitate was subjected to dialysis overnight. Recovered myoglobin was freeze-dried and stored at -70°ĘC until tested. Myoglobin solubility was measured in the range of pH 2 to 11. Various levels (0.2, 0.4, 0.6, and 1.0%) of myoglobin were added to Alaska pollock surimi to determine the effect oin surimi gel. Analysis included texture, color, and differential scanning calorimetry. The highest solubility was found at pH 6. Gels with 0.2% myoglobin showed the lowest force and deformation values, but both values increased as myoglobin addition increased. Color analysis showed the highest whiteness in gels without myoglobin addition and a reverse correlation was found between whiteness and myoglobin addition. DSC showed that enthalpy of denaturation of the last peak decreased as myoglobin addition decreased. The negative effect of myoglobin addition was found on color. Although inferior with regards to gel properties when replaced by myofibrillar proteins, myoglobin did show its own gel-enhancing ability.
Session 89B, Aquatic Food Products: Surimi, gels and by-products
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |