Preparation Of Sago Fluidity Starch And Its Film Forming And Gelling Properties

Starch as a native polymer material which is abundant,renewable,biodegradable and cheap was considered as one of the most promising material in the present world.Sago starch is a new kind of starch originated from Southeast Asia,which is abundant and has great capabilities.However,till now few studies on sago starch are available.The properties of untreated native starch also have certain limitation in many aspects.Therefore,it is necessary to make a modification according to its structural characteristics and physicochemical properties,as well as to investigate its properties after modification.Firstly,we use a method of acid modification on sago starch to prepare a kind of sago fluidity starch which is thin boiling.Through characterization analysis on sago starch before and after modification,we found that after modification the starch granule became smaller,crystalline structure was changed,gelatinization temperature increased,the viscosity decreased obviously,has better film-forming and gelling properties and so on.Secondly,starch film was made by sago fluidity starch as its good film-forming properties.The orthogonal experiment was carried out by the change of starch concentration,plasticizer concentration,drying temperature,sodium alginate concentration and carrageenan concentration to determine the optimal condition to prepare a film with adequate mechanical properties.According to the fracture energy and tensile strength,the optimal solution was determined as 10%starch,25%plasticizer,50?,3%sodium alginate and 3%carrageenan.The results of the optimal solution was 491.5 ± 28,2 J/m2 fracture energy,28.36 ± 2.7 MPa tensile strength and 20.5 ± 1.8%elongation,respectively.Additionally,the primary and secondary factors were determined.Moreover,this study also investigated the influence of the variety factors on mechanical properties of film,and discussed the results from the aspects of theory.Finally,as sago fluidity starch has good gelling properties,the influence of acid modification process include starch concentration,acid amount,acid-reaction time and temperature on gel performance were also studied.The optimal solution of gel strength was obtained by the orthogonal experiment,which was found to be:40%starch,8 h,0.06 N acid,50 ?.The results of optimal solution showed that the gel strength was 54.88 ± 2.51 N.In addition,the influence of variety factors on viscosity was also investigated.Meanwhile,the biocompatibility of sago fluidity starch gel was researched,and concluded that compared with on native sago starch gel,the survival of murine bone marrow stem cells(mBMSCs)on sago fluidity starch gel was higher.Therefore,sago fluidity starch gel has better biocompatibility.