Effects Of ?-carrageenan/k~+ Gel System On The Properties And Structure Of Surimi

Surimi technology can transform low-value small fish into high-value products with commercial value.Myofibrillar protein is largely responsible for structural and functional characteristics of muscle tissue,changes in functional characteristics and spatial structure,and plays a vital role in the quality and yield characteristics of processed meat products.Because ?-carrageenan has ideal stability,thickening and gelling properties,it has been widely used in food processing in recent years under the premise of meeting the use standards.The previous researches mainly focused on the research on the heating method of surimi,the optimization of processing parameters,and the addition of foreign substances to improve the gel properties of surimi.?-carrageenan can enhance the cross-linking between proteins,and ?-carrageenan itself can form a gel,forming a network structure different from surimi gel.Therefore,in this experiment,?-carrageenan/K+gel system was added to surimi and surimi myofibrillar protein to study the quality characteristics,rheology and structure of surimi gel,and the effects of the nature and structure of myofibrillar protein.It aims to provide theoretical guidance and suggestions for the development and utilization of low-value fish and the production and processing of recombinant products.1.The effects of ?-carrageenan/K+gel system on the quality and properties of surimi gel was first studied:The results showed that the ?-carrageenan/K+gel system can increase the surimi gel strength,and it increased with the increase of the addition level.When the addition level was the same,?-carrageenan+KCl improved the gel strength more significantly than ?-carrageenan;The water holding capacity of gel increased with the increase of the addition level.When the addition level was the same,?-carrageenan+KCl had a more significant improvement in gel water holding capacity than ?-carrageenan;However,the cooking loss of gel decreased as the addition level of?-carrageenan/K+gel system increased.The addition of KCl made the cooking loss drop even more;The whiteness of surimi gel was not affected by the ?-carrageenan/K+gel system.2.Secondly,the effects of ?-carrageenan/K+gel system on the rheology and structural properties of surimi gel were studied:The results showed that the ?-carrageenan/K+gel system can increase the storage modulus G'of surimi gel,and it increased with the increase of temperature or angular frequency.The presence of K+made the increase of G' more significant;The addition of ?-carrageenan/K+gel system made the surimi gel network structure smooth,orderly and dense,and the surimi gel network structure was enhanced,thereby increased the surimi gel strength;SDS-PAGE electrophoresis images showed that after the surimi gel with ?-carrageenan/K+gel system was heated,the MHC disappeared and the actin bands did not change significantly.3.Finally,the effects of ?-carrageenan/K+gel system on the gel properties of surimi myofibrillar protein was studied:The results showed that the addition of ?-carrageenan/K+gel system improved the gel strength of myofibrillar gel significantly,and the gel strength also increased significantly with the increase of the addition level.The gel strength of myofibrillar gel with ?-carrageenan+KCl was higher than that of myofibrillar gel with ?-carrageenan.This is because K+increased the gel strength of ?-carrageenan,and the ?-carrageenan gel fragments were embedded in the three-dimensional network structure,so the gel strength can be further increased;The addition of ?-carrageenan/K+gel system significantly improved the water holding capacity of myofibrillar gel.Cross-linking between proteins and colloids leaded to changes in the spatial structure of proteins.The three-dimensional network structure of the protein became denser and the voids became smaller,so that more water was retained in the gel network structure.K+can help improve the gel properties of ?-carrageenan,and further combine more moisture,thereby further improving the water holding capacity of myofibrillar protein gel;In frequency sweep and temperature sweep,G' of myofibrillar protein added with ?-carrageenan/K+gel system has the same trend as G' of the control group,and both increased with frequency or temperature;The addition of ?-carrageenan/K+gel system can change the secondary structure of myofibrillar protein,so that the content of ?-sheet increased with the increase of the addition level,and the content of ?-helix and random curl decreased as the amount of addition increased.The increase of ?-sheet content made the gel network more dense,thereby increased the strength of the gel network.