It was found that a heating at higher temperatures (> 80 C) in
the presence of citric acid led to the acid hydrolysis of amylose and
amylopectin chains, and that affected the gel strength and the
retrogradation of cornstarch gels. Cornstarch gels in the presence of
citric acid became brittle against large deformation and hard to
deform against small deformation compared with the control.
However, in the case where samples are stored for longer time, it is
thought that the effects of adding citric acid are not necessarily
influential, because the retrogradation ratio for all samples with or
without citric acid converge to a constant value.