Effects Of Rice Dreg And Protein Isolate From Rice Dreg On The Gel Properties And Freeze-Thaw Stability Of Silver Carp Surimi

Recently, surimi products have become greatly popular with consumers for its low fat, high quality protein, easy digestion and absorption, good balance nutrition as well as taste delicious. This research investigated the effects of rice dregs (RD) and protein isolates from rice dreg (RDPI) on characteristic of silver carp surimi, including color, water holding capacity (WHC), gel strength and dynamic rheological properties. In addition, the influence mechanism was also been studied by the method of SDS-PAGE, intermolecular chemical interactions, fourier transform infrared spectrometer and microstructure. On the basis of the above research, the changes of surimi gels’ freeze-thaw stability were also investigated as the increasing of RD and RDPI content. This study could provide theoretical guidance and technical for the application of RD and RDPI in surimi-based products. The results were as follows:Firstly, as the content of RD increased, WHC, L*value and whiteness, breaking force and breaking deformation, texture properties and dynamic rheological properties of surimi gels were significantly decreased (P<0.05), while a*value and b*value increased (P<0.05). Sensory scores of surimi gels also decreased with the increasing of RD contents, but the scores were above4when the RD was at a lower content (<1%), which indicated consumers could accept the products.Secondly, the WHC, breaking force and breaking deformation, and texture properties of surimi gels increased with the addition of RDPI up to1.0%, but decreased as more addition of RDPI (>1%)(P<0.05); there was no significantly effects on spring when the addition of RDPI under1.0%(P<0.05), but followed a decrease (P<0.05). Beside, as the increasing of RDPI contents, L*value and whiteness, dynamic rheological properties decreased while a*value and b*value increased. Therefore, on the whole,1.0%RDPI was the suitable addition in surimi products. In addition, sensory scores of surimi gels also decreased with the increasing of RD contents, but the scores were all above4when RDPI added. Thirdly, SDS-PAGE, intermolecular chemical interactions, fourier transform infrared spectrometer and scanning electron microscopy results indicated that there was little interaction between RD/RDPI and fish proteins. Therefore, RD/RDPI was used as functional fillers in surimi products.Finally, during the freeze-thaw process, WHC, L*value and whiteness, breaking force and breaking deformation, and texture properties of surimi gels significantly decreased (P<0.05), while TBA value, a*value and b*value increased (P<0.05). The addition of RD decreased the WHC, whiteness, breaking force and breaking deformation, and texture properties of surimi gels, but there were no significantly changes on the above properties when RDPI added. Therefore, temperature variation should be greatly controlled for keeping the qualities of surimi products in circulation.Results of the research have certain reference significance on the application of RD/RDPI into surimi products. Meanwhile, it also analyzed the influence mechanism, so there were important references to further academic rearch.