Preparation Of Cold Water Soluble Potato And Tapioca Starch And Its Structures And Properties

Starch is a natural polysaccharide polymer, can be widely used in food andother industries process. However, the insolubility, high viscosity and high degreeof retrogradation of defects are the serious impediments to processing andapplication of starch. In this paper, potato and cassava starch are the raw materials,and the ball-milling is used for the preparation of cold soluble starch to study thetwo materials’ structure and properties.Using ball milling method can significantly improve the cold water solubilityof the potato starch and cassava starch. As the ball speed, grinding time, input rate,and the ball to powder ratio of starch concentration increase, the cold watersolubility of starch exhibit the tendency of different rise. Different cold watersolubility is obtained from the comparative preparation of potato and cassava starchand it is found that, with the increasing of cold water insolubility, there is also anincrease in water holding capacity, and the turbidity and freeze-thaw stability of thetwo starches are decreased, while the double refraction of the two starchescompletely disappeared.By using Box-Behnken design model, and undergone through the responsesurface method optimization, the best obtained granular cold water soluble potatostarch is: milling time (X1)3.7h, filling rate (X2)27%, the ball feed ratio (X3) is6.2:1. From this optimum condition,80.2%of the cold water solubility of granularcold water soluble potato starch is obtained. Double refraction of the starchdisappeared, X-ray diffraction shows the high dispersed peaks, starch particles’ sizebecome large, the particles have rough surface due to cracks, flat in non-uniformform and have complete granule surface with average diameter increased to68.24μm. Such starch, without generating new group; it starch do not havegelatinization peak, all the viscosity will go down, solubility of starch, swellingpower and water holding capacity increases up to29.6times,9.5times and4.4times respectively. Freeze-thaw stability and turbidity of potato starch is lower thanoriginal potato starch.By using Box-Behnken design model, and undergone through the response surface method optimization, the best obtained granular cold water soluble cassavastarch is: milling time (X1)4h, filling rate (X2)14%, the ball feed ratio (X3) is6.5:1. From this optimum condition,72.6%of the cold water solubility of granularcold water soluble cassava starch is obtained. Double refraction of the starchdisappeared, X-ray diffraction shows the high dispersed peaks, starch particles’ sizebecome large, the particles have rough surface due to cracks, have regular flat shapeand have complete particle shape with average diameter up to48.21μm. Such starch,without generating new group; it does not have gelatinization peak, all the viscositywill be reduced, solubility of starch, swelling power and water holding capacityincreases up to40times,11.8times and1.5times of the original starch respectively.Freeze-thaw stability and turbidity of cassava starch is lower than original cassavastarch.