Dual modification of native white sorghum (Sorghum bicolor) starch via acid hydrolysis and succinylation

Abstract

The present study investigated the effect of succinylation, acid-thining and combination of both on functional, textural and storage characteristics of starch isolated from white sorghum (Sorghum bicolor) grains. Prior to succinylation, native sorghum starch (NS) was acid-thinned with 0.1 M, 0.5 M and 1.0 M HCl solutions, separately. Succinylation of both NS and acid-thinned starches reduced percent retrogradation in starches while peak, cold paste and setback viscosities increased significantly. The extent of changes in various textural attributes like gumminess, hardness and chewiness were significantly reduced on refrigerated storage of starch gels. Similarly, decline in paste clarity was less pronounced in dual modified and single modified succinylated starches on cold storage. The results suggested that Su-At0.1M and Su-At0.5M starches showed lower percent retrogradation than At0.1M and At0.5M starches. Also they produced less gummy and chewy textures on storage which imply their application in puddings, custards and dairy desserts where weak gel formation is desirable. Also it was observed that Su-At1.0M gels had high degree of clarity, low hot paste viscosity and lower retrogradation tendency than At1.0M starches, which makes former extremely important in preparation of frozen pie fillings where high degree of clarity and storage stability is required combined with low hot paste viscosity.