Combination model for the spatial partition of surimi protein and hydroxylpropylmethylcellulose

The objectives of this study were to investigate the combination model of hydroxylpropylmethylcellulose (HPMC) added with surimi protein gel. HPMC forms and addition timing apparently affected the structural geometry of the combination gel matrix and resulted in the variation in rigidity, thermal stability and gel strength. Upon viewing of the scanning electron microscopy (SEM) photographs, the horse mackerel surimi displayed a large holes and smooth protein matrix, while, the HPMC added surimi displayed a porous or rough structure. According to thermal gelation and microstructure analysis, the filling effect existed in HPMC added surimi. HPMC existed as dispersed particles in HPBC (HPMC powder added before chopping) and HPDC (HPMC powder added during chopping) surimi. HPMC remained soluble in the interstitial fluid of the surimi gel matrix in HGBC (HPMC gel added before chopping) and HGDC (HPMC gel added during chopping) surimi. These four 'simple' filled gels turned to 'complex' filled gels during the process of thermal gelation caused by certain interaction of the gelled HPMC and protein gel matrix. HGAC (HPMC gel added after chopping) surimi formed an interpenetrating structure together with a gelling protein and a gelling HPMC.