The effect of concentration and botanical source on the gelation and retrogradation of starch

Abstract

Abstract The changes in shear modulus of pea, wheat, maize and potato starch gels with time, at concentrations between 10 and 40% w/w, were followed. In this range, the cooling of gelatinised dispersions of starch resulted in turbid, elastic gels. The initial rate of development of stiffness of the gels followed the order: pea>maize>wheat>potato, and was related to the amount of amylose solubilised during gelatinisation. The initial gelation was not reversed on heating to 100° C. There was also a long‐term increase in gel stiffness, which was thermally reversible. This long‐term increase, linked to a crystallisation involving amylopectin, followed the order: pea>potato>maize>wheat. With increasing starch concentration this latter process becomes more important.