Study On The Properties Of Compound Gel Based On Tremella Polysaccharides And Its Application In Jelly

Tremella is an edible fungus with homology of medicine and food,and its functional component Tremella polysaccharide（TPS）is an acidic heteropolysaccharide with good antioxidant activity.However,there are few reports on the gel properties of Tremella polysaccharide compound gums.Therefore,in this paper,Tremella polysaccharides were extracted and physicochemical properties were measured.And the gel characteristics of tremella polysaccharide-konjac glue（KGM）and tremella polysaccharide-whey separation protein（WPI）were studied under different conditions.In addition,based on the research on Tremella polysaccharide compound gel combined with practical application,Tremella polysaccharide jelly was developed.The main results are as follows:1.After the fresh Tremella was dried,the Tremella polysaccharide was extracted by water extraction and alcohol precipitation,and the properties of the freeze-dried Tremella polysaccharide were analyzed.The neutral sugar content of Tremella polysaccharide is 71.53%,uronic acid content is 22.82%,mainly composed of mannose（19.70±0.56%）,other monosaccharide content is galacturonic acid（10.92±0.25%）,glucuronic acid（8.63±0.39%）,xylose（7.08±0.28%）,fucose（6.94±0.26%）,and glucose（5.02±0.34%）.TPS has good antioxidant activity,and the scavenging rates of DPPH radical,hydroxyl radical and ABTS radical at the concentration of 5 mg/m L are 26.13%,38.11%and 93.98%,respectively.The rheological results show that the apparent viscosity and modulus increase with the increase of TPS concentration.TPS cannot form gel in the low frequency region,but can form weak gel in the high frequency region.small,indicating that TPS has good acid-base stability.2.The effects of KGM addition,p H and cations on the properties of TPS-KGM gel were studied.The increase in the amount of KGM added increased the density of molecular chains,enhanced the hydrogen bonding,and increased the viscosity and modulus of the TPS-KGM gel and improved thermal stability.The viscoelasticity of the TPS-KGM gel was the best at p H 6.This may be due to the hydrolysis of polysaccharides at p H 4,and the partial deacylation of KGM induced under alkaline conditions,which affects the molecular conformation,resulting in a decrease in viscosity and modulus.The addition of cations can shield the electrostatic effect and enhance the gel performance,but too much cations will lead to self-aggregation between polysaccharides,thus affecting the gel stability.Compared with the TPS-KGM gel without cations,the viscosity and modulus of the TPS-KGM gel were slightly reduced with the addition of cations,and the thermal stability of the TPS-KGM gel was more sensitive to Ca²⁺than Na⁺.3.The effects of WPI addition,p H and cation on the properties of TPS-WPI composite gel were studied.The interaction between TPS and WPI was gradually enhanced with the increase of the amount of WPI added,forming a dense gel network structure and restricting the flow of water.The results of protein solubility analysis showed that hydrophobic interaction,disulfide bond and hydrogen bond were the main forces of TPS-WPI gel.The viscosity,modulus and water holding capacity increased with the increase of p H,the molecular arrangement in the gel was more orderly to form low-crystalline complexes,and the gel network was denser to limit the migration of water.The addition of cations changed the spatial structure of WPI,and TPS competed with WPI for salt ions,resulting in phase separation of the mixed system.4.Based on the research of Tremella polysaccharide compound gel,Tremella polysaccharide jelly was developed.The optimal formula obtained by single factor and orthogonal experiment optimization is:the ratio of carrageenan-konjac gum compound is 3:2,the concentration is 2.5%;the additionof WPI is 2%;the addition of TPS is 0.5%;The addition of sucrose is 8%;the addition of citric acid is 0.1%;the addition of Ca Cl₂is 0.1%.The sensory and texture properties of the optimized Tremella polysaccharide jelly and the commercial jelly were compared.The sweetness and sourness were moderate,which met the national standard and met the sensory preferences of most people.