Effects Of Three Plant Polyphenols On Gel Properties And Preservation Quality Of Surimi-Based Products

In recent years,surimi products have been favored by consumers because of their high protein,low fat and good taste.However,there are some problems such as poor gel strength,easy spoilage and poor preservation quality of surimi,which limits its application and popularization.Plant phenolic compounds can not only enhance the gel strength of surimi as cross-linking agent but also can improve the preservation quality of surimi products as natural preservatives.It is a good choice to solve the problem of poor gel strength and poor storage resistance of surimi products.At present,although plant polyphenols have been reported to improve cross-linking ability of proteins and improve the gel properties of surimi,the mechanism of polyphenols and proteins is not yet clear,and different polyphenols have different effects on fish protein,different polyphenols also have different gel properties and preservation performances.Therefore,in this paper,frozen silver carp surimi was used as raw material,three plant polyphenols such as tea polyphenols(TP),apple polyphenols(AP),and grape polyphenols(GP)were used as additives.The effects of three plant polyphenols on color,water holding capacity,gel strength,TPA,gel strength,rheological properties,SDS-PAGE,microstructure of surimi,and the effects of three plant polyphenols on the preservation of surimi quality during cold storage in this study,which surimi product was stored at 4℃and tested for whiteness,water-holding capacity(WHC),gel strength,TBA,TVB-N,total numbers of colony and protein pattern at different storage times(0,5,10,15,20 d),were studied to explore the interaction between polyphenols and fish protein in different plants polyphenols and the different preservation effect of different plant polyphenols.The results of the study are as follows:1.The total phenol content of TP,AP,GP were 98.96%,76.11%,81.50%,respectively,and the maximum absorption wavelengths of the three were 274 nm,283 nm,and 278 nm,respectively.When the temperature was below 70℃,the thermal stability of the three kinds of polyphenols is good,and heating time has little effect on the properties of polyphenols at 70℃(P>0.05).While the temperature was above 70℃,there was a significant effect on absorbance of plant polyphenols,which may due to the structure change of polyphenols.The order of DPPH radical scavenging ability is TP>VC>GP>AP;the main components of frozen fish gills were:moisture accounted for 76.44%,salt soluble protein accounted for 10.62%,water soluble protein accounted for 2.16%,insoluble protein accounted for 5.78%,and fat content accounted for 2.53%.Surimi is rich in protein and low in fat.2.The addition of plant polyphenols could significantly decrease the whiteness value,increase the value of a~*and b~*of surimi gel,and the range of change was positively correlated with the concentration.The suitable concentration of polyphenol could improve the water holding capacity,gel strength,hardness,chewiness of surimi gel.The gel properties of the surimi gels reached the maximum with the addition of 0.1%TP,0.15%AP and 0.15%GP.At 90℃,the maximum G’values of the surimi gels and the corresponding polyphenol concentrations corresponding to the maximum gel strength were the same as those of the maximum gel strength.The addition of plant polyphenols could reduce the ionic bond and hydrophobic interaction content in the surimi gel,but could significantly increase the hydrogen bond and disulfide bond content.Plant polyphenols can enhance the gel strength by increasing the content of disulfide bond in surimi gel.Plant polyphenols could weaken the strength of MHC band in surimi gel and produce high molecular protein aggregates.More smooth and dense microstructures of surimi gel could be obtained by adding plant polyphenols.3.The addition of plant polyphenols could increase the water holding capacity and gel strength of surimi products,and significantly delay the decrease of water holding capacity and gel strength(P<0.05).The whiteness of surimi decreased as polyphenols added.During the preservation process,the control group and GP group could maintain the color and luster of surimi gel and the whiteness value of surimi products,while TP group and AP group showed a tendency of slight decrease and then a gentle trend.During preservation,plant polyphenols had little effect on the whiteness of surimi products.The quality of surimi products began to decline rapidly at 4℃to 10 days,and the addition of polyphenols could significantly inhibit or delay the increase of the value of TBA、TVB-N(P<0.05),and the growth of microbes,which indicated that polyphenols had a better fresh-keeping effect on surimi products,the order of the preservation ability is TP>GP>AP.The effect of polyphenols on fish surimi products during preservation was significant.The MHC band of surimi gel protein showed a tendency of degradation,the extent of MHC band degradation of TP in the three polyphenols was the smallest.