Effect Of Endogenous Formaldehyde On Gel Properties Of Squid Surimi

Squid has a high nutritional value,containing low fat and high protein.It has become one of China's important economic seafood,and it is increasingly favored by surimi producers because of its abundant resources,high proportion of edible parts,easy processing,non fishbone and so on.At the same time,in recent years,the problem of excessive formaldehyde content in squid is particularly prominent,affecting the formation of squid surimi gel,resulting in domestic and foreign squid production and processing enterprises suffered huge losses.Therefore,in this paper,Peru squid was as the material and the effect of endogenous formaldehyde(FA)on squid surimi gels and how to control it was explored.The main results were as follows:1.Frozen storage had an influence on the change of FA,DMA,TMA and TMAO content in squid surimi.Quality(textural properties,gel strength,T23 transverse relaxation,water hold capacity and cooking loss)of squid surimi gels by the second of the gelation method is better when the low gelation temperature(40?)and the gelation time(30 min).Microstructure of squid surimi gels under this condition were smooth and uniform distribution by Scanning electron microscope(SEM).2.Effect of the different concentrations of FA on the gel properties of myofibrillar proteins(MP)in Peru squid(Dosidicus gigas)were investigated by in vitro simulation system.The results showed that the whiteness,hardness,chewiness,breaking force and cooking loss of MP gels increased significantly with the increase of FA concentration,whereas water-holding capacity,the sulfhydryl groups and surface hydrophobicity decreased gradually,which indicated that the water holding capacity of proteins gel became worse.The chemical force(hydrogen bonds,disulfide bonds,ionic bonds,hydrophobic interactions)and peaks area proportion of transverse relaxation time T2 of treatment groups changed obviously,especially for the peaks area proportion of T23 and T24,which indicated that protein conformation was changed and water flowing of protein gels showed increasing.the microstructure of gel sample of the treatment groups were more rough,uneven,large gap and fragile,which showed that the network structure of the protein gels were damaged,became loose and easy to break with the presence of FA.3.The best condition for processing fish balls was to use the second section of the gelation method(40? 30 min,100? 4 min),when the concentration of grape seed extract(GSE)was 0.05%and egg albumin(EA)was 5%.Grape seed extract could inhibit the thermal decomposition of TMAO and reduce the FA,DMA and TMA content in fish balls during the process of production.Grape seed extract and egg albumin could increase the hardness,elasticity and gel strength,improve the water-holding capacity,decrease the T23 transverse relaxation time and water mobility.And the effect of compound group on Peru squid fish balls was better,and the whiteness of its increased.