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Thermal Syneresis Affected by Heating Schedule and Moisture Level in Surimi Gels
Author(s) -
Park Y.D.,
Yoon K.S.,
Lee C.M.
Publication year - 2008
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2007.00644.x
Subject(s) - syneresis , chemistry , moisture , thermal stability , water content , thermal , chromatography , food science , thermodynamics , organic chemistry , physics , geotechnical engineering , engineering
The extent of thermal syneresis in protein gelation is indicative of thermal and freeze‐thaw stability as well as the network integrity of a protein gel. Thermal syneresis in Alaska pollock surimi gels was examined under different heating schedules (40 °C/20 min to 90 °C/30 min, 60 °C/20 min to 90 °C/30 min, and 90 °C/20 min to 90 °C/20 min) at varying moisture levels (80%, 82%, and 84%). The extent of syneresis and gel firming was monitored by centrifugation expressible moisture and penetration force, respectively. The occurrence of 2 distinct peaks as a function of time for both thermal syneresis and gel firming suggests that a multistage aggregation is involved in the formation of gel network. All syneresis preceded gel firming upon protein aggregation. Increasing the moisture content in the gel delayed the 2nd stage of protein aggregation. The 60 °C/20 min preheating followed by 90 °C/30 min postheating resulted in significantly greater thermal syneresis and gel weakening compared to 40 and 90 °C preheating. Changes of gel structure clearly reflected thermal syneresis when the size of water pores became smaller with initiation of network formation and progressively larger upon further heating. Thermal syneresis history during protein gelation can be used to predict thermal and freeze‐thaw stability.