| In this paper,Dioscorea alata L.was used as raw material,and its starch was extracted by NaOH soaking.The physicochemical properties,gelatinization and texture properties of the starch were studied.The Dioscorea alata L.juice after starch extraction was used in the development of Dioscorea alata L.jelly.The main research contents are as follows:(1)Dioscorea alata L starch extracted by NaOH soaking was used as raw material,and the physical and chemical properties of the starch were analyzed by comparing with wheat,mung bean and potato starch.The results showed that the amylopectin content of different types of starch was different,the content of amylose was 17.98% to 37.71%,the amylose content of the starch was lower than that of wheat starch and mung bean starch;the transparency,sedimentation,water holding and heat stability of the starch were better,but the freeze-thaw stability was poor,which was not suitable for the frozen products;different types of starch The solubility and swelling power of the starch were potato starch >Dioscorea alata L.starch > mung bean starch > wheat starch,and all increased with the increase of temperature.The gelatinization temperature of the starch was 84.58 ?,which was difficult to paste,but the thermal stability was better.(2)The changes of properties of the compound system of xanthan gum,guar gum,Arabic gum and Dioscorea alata L.starch in the gelatinization process were studied.The results showed that the effect of different concentrations of xanthan gum on the viscosity of Dioscorea alata L.starch was not significant,but the addition of xanthan gum enhanced the stability of the compound system.Guar gum and Arabic gum improved the peak and final viscosity,the regeneration value and disintegration value of the system,and delayed the gelatinization of the starch of the Dioscorea alata L.When the amount of guar gum was5%,the effect was the most obvious;xanthan gum had the most effect on the starch of the Dioscorea alata L.,but the gelatinization effect of guar gum and Arabic gum on the starch was not obvious;When the amount of xanthan gum and Arabic gum was 5%,guar gum was 4%,the effect on the freeze-thaw stability of the starch was the greatest;the transparency of the starch paste was higher than that of the sole starch paste,and guar gum had the greatest effect on the starch of the Dioscorea alata L.starch The transparency effect is the best,when the amount of addition is 5%,it reaches 8.4%.The results of electron microscopy showed that the compound system changed greatly after adding colloid.The natural starch paste presents thin,fragile and uneven twisted particle fragments.Starch paste containing guar gum and its hydrolysate showed thick,compact and shrinkage starch structure granular residue.(3)The effects of citric acid,xanthan gum concentration,salt,sucrose and potassium sorbate on the compound system of Dioscorea alata L.starch and xanthan gum were studied.The results showed that xanthan gum enhanced the texture properties of the compound system;citric acid had little effect on the hardness of the compound system,and the rising trend of chewiness and adhesion was slowed down after 0.04% and 0.06%,respectively.At 0.08%,the elasticity and cohesion were improved The value is the largest.From the point of view of the whole system,the influence of salt on the gel structure of the system enhanced the texture characteristics of the system at low concentration.After more than 0.06%,the addition of salt reduced the texture characteristics of the system;the hardness and chewiness of the composite system increased with the addition of sucrose,reaching the maximum value at 0.6%,and the hardness and chewiness of the gel system decreased after 0.6%.The gel elasticity and cohesiveness reached the maximum value at0.6% and 0.8% respectively.When 0.2%-1.0% was applied,the effect of sucrose on the adhesion of the system was not significant.The addition of potassium sorbate greatly reduced the hardness and chewiness of the composite system,reached the maximum value at 0.04%,and had the lowest value at 0.08%.The maximum and minimum values of cohesiveness appeared at 0.06% and 0.08% respectively.With the increase of potassium sorbate concentration,the adhesion first increased and then decreased,and the maximum value appeared at 0.08%.(4)The juice of the starch extracted from the Dioscorea alata L.was filtered with two layers of gauze,and the upper juice was put into the production of the jelly.The best ratio of the jelly was determined by single factor and orthogonal experiment: 14% of the Dioscorea alata L.extract,9% sucrose,1% compound gum,0.1% citric acid. |
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