Esterified And Cross-linking Potato Starch: Synthesis And Application In Stirred Yogurt

The purpose of the article is synthetizing modified potapo starch which can be used in stirred yogurt. Using potato starch as main raw material, acetic and succinic anhydride as esterifying reagent, sodium trimetaphosphate as cross-linking agent, the reactive conditions of modified potato starch have been tested in experiments. Physical and chemical properties of production have been analyzed; its effects in the application of stirred yogurt have been tested.Effects of temperature, time, pH and amounts of modifying agent on modified potato starch have been studied. Based on orthogonal experiments, substituted degree as indexes, the optimum conditions of succinic acid -esterified potato starch are resulted as follows: pH9.0, amounts of succinic anhydride 4%, time 1h and temperature 30℃for esterification reaction, substituted degree is 0.0372; the optimum conditions of acetic acid -esterified potato starch are resulted as follows: pH9.0, amounts of acetic anhydride 10%, time 1.5h and temperature 25℃for esterification reaction, substituted degree is 0.0950; sediment volume as indexes, the optimum conditions of cross-linking potato starch are resulted as follows: pH11, time 3h, amounts of sodium trimetaphosphate 2% and temperature 45℃for cross-linking reaction, sediment volume is 1.99. The results of substituted degree and sediment volume are ideal.Base on review of esterification and cross-linking reactions, we studied the preparation of complex modified starch by continual reactions in one-step synthesis way. Moreover, the transparency, viscosity, viscosity stability and ageing resistance have been analyzed. The results show that succinic acid -esterified complex modified potato starch has higher stability in viscosity, heat stability and ageing resistance; acetic acid -esterified complex modified potato starch has higher transparency; the two complex modified potato starch has same stability in shearing stress and acidoresistance.At last, the effect of succinic acid -esterified complex modified potato starch as additive in stirred yogurt has been studied. The results show that adding the product can reduce educe ratio of whey, raise viscosity and structural condition of stirred yogurt. When the amount of succinic acid -esterified complex modified potato starch is 0.3% and the amount of xanthan gum is 0.04%, the qualities of stirred yogurt are optimization. Hoping the succinic acid -esterified complex modified potato starch will be used in stirred yogurt and replace the imports.