Study On The Preparation Of Cassava Resistant Starch And Mechanism

Along with the living standard upturning, people pay more attention to thefunction of food. Resistant starch is used on food processing to raise fibercontent and improve the quality of food, what is better than traditional dietaryfibers. Therefore, resistant starch as composition of functional food containinglow caloric, high dietary fibers will have important application value.We adopt single factor experiments in order to study the influence of starchpastes concentration, gelatinization temperature, pullulanase quantity, reactiontime, storage time, zymolysis temperature on resistant starch content. On thisfoundation, we chose the Starch pastes concentration, quantity of the pullulanase,the time of the reaction, zymolysis temperature as factors of orthogonalexperiment. The experiment results show that starch pastes concentration hasstrong influence on the content of RS. Zymolysis temperature has little influenceon the content of RS. The optimum reaction conditions is showed as follows: thestarch pastes concentration is 20%, the pullulanase quantity is 4u/g starch, thereaction time is 6 hours, the zymolysis temperature is 600C, the content of RSamounts to 13.36%.Through carried on take-off and non take-off treatment on starch, wediscover take-off treatment is advantageous to the formation of RS. Theprocessing of zymolysis by Pullulanase makes amylose taken off, and theresistance of moving diminishes, movement of chain is more easily, that is good for crystallization, and accelerate returning of starch, increase the content of RS.Through discussing the relationship between amylose content and resistantstarch content, conclusions indicate that the increase of amylose content isadvantageous for increasing the content of resistant starch.The analysis results of XRD and SEM indicate that resistant starch isformatted by recrystallize, and its grain surface structure is different withoriginal starch. The sample that contains more resistant starch, contains morecrystal, and grains arrange more close. The results of water-holding capacitydetermination indicate: The water-holding capacity of resistant starch is greaterthan original starch, but smaller than other dietary fibers.