Assessing the Dynamic Rheology at Various Frequencies of Surimi Paste as Affected by Heating Rates and Moisture Contents

초록

Dynamic rheological properties of Alaska pollock (AP) surimi as affected by various heating rates (1, 5, 10, 20 and 30C/min) and moisture contents (75, 78 and 81%) were investigated at different frequencies (0.1, 1 and 10Hz). Elastic modulus (G) decreased as heating rate increased regardless of frequencies applied during temperature sweep. A temperature lag between heating plate and sample specimen was found at heating rates above 5C/min. A magnitude of change in phase angle between 30 and 50C, where light meromyosin unfolds and aggregates, increased significantly as heating rates changed from 1 to 30C/min, indicating fast heating is not favored for gel formation of pollock surimi. The slowest frequency applied (0.1Hz) was more effective in examining the dynamic rheology of fish proteins. High moisture content (81%) exhibited a slowly ascending G curve after gelling point and indicated slow completion of gelation. Practical ApplicationsOur results showed that the controlling heating rates and moisture contents may be employed to optimize the gelation of Alaska pollock (AP) surimi. In addition, the low frequency (0.1Hz) well differentiated the effects of heating rate and moisture content on the rheological properties. Especially, the gelation with a slow heating rate, which significantly enhanced the rheological properties of AP surimi gels, maybe practically applied to control the heating process of various surimi seafood products, such as fish balls. Our new findings may be applied to estimate the effect of heating rate and the moisture contents on the rheological properties of surimi from other species.

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