Abstract: Objective:The mechanism of interaction between additives especially polysaccharide gums and sweet potato starch(SPS) in the production of its noodles was investigated in order to provide a theory foundation on improving the quality of sweet potato starch noodles(SPSN).Method:Combining the assay of the glass transition temperature by differential scanning calorimetry,determination of leaching amylose amount and interaction between additives and sweet potato starch and infrared spectrum analysis of mixture systems,the mechanism of interaction between additives and sweet potato starch was studied.Result:These mixture systems contained CMC,carrageenan and SPS were incompatible,while those mixture systems contained alum,salt,soybean protein,glycerol,other polysaccharide gums and SPS were compatible.The mixture systems contained KGM,ASK and SPS were more steady than others.Additives combined with amylose in SPS.These interactions were strong or weak.The NaCl can weaken slightly the interactions between polysaccharide gums and SPS,while carbamid can weaken strongly their interactions.The-OH peaks in these infrared spectrum peaks of SPSN contained additives were displaced and other peaks were not displaced compared with the original SPSN.Conclusion:It was found out that the mechanism of interaction between KGM,ASK and SPS was described as follows:the mixture system contained KGM,ASK and SPS was compatible.There was no new functional group in this mixture system.Their amylose and exterior chains in amylopectin juxtaposed each other by hydrogen bond,which existed inner and exterior chains,and then form minicrystal zone,which acted as junctures.The net in mixture system was held together by countless junctures so that sweet potato starch gel contained KGM and ASK,thushad a strong texture.The interaction between SPS and alum mainly was static electricity.

Key words: sweet potato starch noodles, polysaccharide gums, sweet potato starch, glass transition, infrared spectrum