Effect Of Plasma-activated Water Combined With Heat-moisture Treatment On Structure And Properties Of Starch

As an important renewable and biodegradable natural resource,starch plays an irreplaceable role in human life activities.Starch physical modification is a common modification method.As one of the most comon physical modification technology,heat-moisture treatment(HMT)has the advantages of green environmental protection,energy saving and high efficiency.In this study,potato starch,different chain/branch ratio maize starch and different relative crystallinity microcrystalline starch(MS)were selected as raw materials.The effects of plasma-activated water combined with heat-moisture treatment(PAW-HMT)on the multi-scale structure and properties of the starch were studied.The main research contents and conclusions include the following aspects:1.Effect of PAW-HMT on the structure and properties of starch under different HMT conditionsPotato starch was used as raw material,the moisture content was 25% and 30%,and the moisture temperature was 100 ? and 120 ?.Compared with DW-HMT,the crystal structure,particle structure and thermal properties of starch were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM)and differential scanning Calorimeter(DSC).Through the study of the structure and properties of starch under different HMT conditions,the optimal conditions were found.2.Effect of PAW-HMT on the structure and properties of starches with different amylose/amylopectin contentThe maize starches with different amylose/amylopectin content(waxy maize and normal maize starch)was used as starting material.The modified starch was obtained by PAW-HMT or DW-HMT through using the moisture content of 20% and the temperature of 120 ?.The modified maize starches with different amylose content was analyzed and characterized.The results showed that,compared with DW-HMT,the long-range and short-range ordered structure of the starch treated with the PAW-HMT increased,the content of RS increased and the physical and chemical properties of the starch were also obviously changed.The studyfound that PAW-HMT modification has significant differences in the structure and properties of maize starches with different amylose/amylopectin content.The most important thing was that the modified effect on RS content of waxy corn is more obvious.3?Effect of PAW-HMT on the structure and properties of MS with different crystallinityThe MS with different relative crystallinity(RC)starch was used as raw material,the modified starch was obtained by PAW-HMT or DW-HMT through using the moisture content of 25% and the temperature of 120 ?.The modified starch with different crystallinity was analyzed and characterized.The results showed that compared with DW-HMT modified starch,the average particle size of PAW-HMT modified starch particles became smaller,the long-range and short-range order of molecules increased,and the WBC and SV values increased.Comprehensive comparison found that PAW-HMT treatment has a more significant effect on the morphology,crystal structure and properties of MS particles with low crystallinity.