Effects Of Critical Heating And Freeze-thawing Treatment On The Stabilization Of Synergistic Effect Of Potato Starch/Xanthan Gum Mixture System

Starch has some problems such as unstable paste viscosity,poor gelatinization characteristics and poor heat resistance after gelatinization,which can not meet the requirements of quality characteristics of starch-based food processing.Hydrocolloids as a functional polysaccharide commonly used in food processing,which can effectively improve the processing and quality characteristics of starch-based foods.Starch simple mixed with hydrocolloid is currently the most commonly used method,But the interaction between starch and hydrocolloid are mostly limited on the outside of the starch granules.In addition,starch and hydrocolloid have strong interaction,and there are many problems such as poor stability of compound system and large randomness of synergistic effect in practical application.Therefore,critical heating and freeze-thawing treatment was used to control the interaction mode between potato starch and xanthan gum and enhance their interaction.By studying the physical and chemical properties,structure properties,functional properties and digestive properties of the complex,the steady-state mechanism of potato starch/xanthan gum complex system was clarified,and the prepared complex was applied to the processing of chicken meatballs to improve the texture and quality characteristics of chicken meatballs.The main results are as follows:(1)The apparent storage stability test showed that the potato starch/xanthan gum(PS/XG)compound water system did not appear delamination after critical heating and freeze-thaw(CHFT)treatment,and the dry matter had no peeling phenomenon.The PS/XG composite granula can be observed by microscope to aggregate,and the polarized cross structure is weakened,but the granule morphology remains intact.Native potato starch(NPS)has high WSI,SP,WHC and transmittance.After adding XG and physical treatment,the properties of PS/XG composite are significantly reduced.And with the increase of XG addition,it showed a decreasing trend,among which CHFT treatment decreased the most significantly.At the same time,CHFT treatment resulted in the dissolution of soluble starch components and increased the interaction sites with XG molecules,thereby significantly increasing the water and oil absorption capacity of starch.Therefore,the critical heating and freeze-thawing treatment significantly improved the apparent properties of the PS/XG compound aqueous system and the physicochemical properties of the dry matter.(2)SEM images showed that CHFT treatment significantly changed the surface microstructure of potato starch granula,which were partially fused and adhered together.The results of XRD,FTIR and NMR showed that CHFT treatment reduced the relative crystallinity and order degree of potato starch while maintaining the crystal structure.According To the results of thermal properties,the To of natural potato starch was 62.79? which increased To 67.65? after CHFT treatment.The addition of XG and physical treatment significantly increased the To,Tp and Tc of starch,and the gelatinization enthalpy decreased from 15.95 J g-1 to 11.79 J g-1.Therefore,CHFT treatment enhanced the synergistic effect with XG by inducing the dissolution of components in starch particles,and formed a composite matrix attached to the surface of starch particles,thus stabilizing and strengthening starch granula.(3)RVA experiment showed that CHFT treatment significantly changed the gelatinization behavior of PS/XG composite in pH 3 and pH 7 environments and 0.1 mol/L CaCl2 environment,significantly reduced the PV and disintegration value of the composite,and significantly increased the TV,BD,FV,PT1 and PT2.The PS/XG composite treated by CHFT showed clear grain contours at 50?,70? and 90?,indicating that the rigidity/compactness of starch granula was significantly increased.The PS/XG composite with gel hardness,springness,chewiness,cohesiveness and resilience also significantly increased?The surface of the gel degree of adhesion is reduced,and CHFT treatment significantly reduced the syneresis,the compact structure of the gel network,the preparation of the gel after 5 times of freezing and thawing can still maintain its internal microstructure.This indicates that the prepared gel has good freeze-thaw stability.In addition,CHFT treatment significantly reduced the content of RDS and increased the content of SDS and RS.(4)The prepared PS/XG composite was added to the chicken meatball to improve its quality characteristics.The conclusions are as follows:the chicken meatballs treated with CHFT starch have good water retention,the cooking loss rate is the lowest(as low as 6.16%),and the meatballs have compact,elastic and smooth section.The color and pH of meatballs did not change much after starch was added.The hardness(2311.95 g)and chewiness(1112.23 g)of pure chicken meatballs were higher,but the elasticity(0.78)and resilience(0.29)were worse,and the taste was worse.The hardness(2920.30 g),elasticity(0.86),chewiness(1775.36 g)and resilience(0.38)of chicken meatballs treated with CHFT starch were significantly increased.In addition,the sensory score of chicken meatballs with CHFT-treated PS/XG composite was the highest,indicating that CHFT-treated PS/XG composite significantly improved the texture and quality characteristics of chicken meatballs.