Physicochemical Properties and Their Correlation of Starches from Eight Sweet Potato Cultivars

The starches obtained from 8 different sweet potato cultivars were used as materials,the structural characteristics(the shape and size of granule,and crystallization)was explored. Simultaneously,the functional properties(pasting properties,gel texture,solubility,swelling ability and freeze-thaw stability)were investigated. Subsequently,the correlation between them was analyzed. Results showed that,the amylose contents of sweet potato starch(SPS)samples were different among cultivars. There was no significant difference in particle morphology among different varieties,and they all had typical A-type diffraction patterns. The starches differed in their mean granule sizes and gelatinization parameters. The solubility and swelling power of SPS increased along with the increasing of temperature. With the increasing of freeze-thaw cycles,the syneresis of starch gel rose. Pearson’s correlation analysis indicated that amylose content was positively correlated to setback,hardness,gumminess,chewiness,and syneresis(r=0.807,0.721,0.722,0.734 and 0.803,respectively,P<0.05). While it was much negatively correlated to resilience(r=-0.832,P<0.05). The average size of starch granules was negatively correlated tocohesiveness and swelling power(r=-0.762,-0.775,respectively,P<0.05).In addition,setback of pasting was positively significantly(P<0.05)correlated to the hardness,gumminess,and chewiness of gel,while it was negatively significantly(P<0.05)correlated to cohesiveness. These results could provide some scientific basis for the deep-processing and the selection of SPS in specific application fields.