Physicochemical and textural properties of corn starch gels: Effect of mixing speed and time

The influence of mixing speed (15, 150 and 350 rpm) and heating time (10, 30 and 45 min) at 95 °C on physicochemical and textural properties of corn starch gels was investigated. The gels prepared at 15 rpm and 10 min had the highest hardness, cohesiveness and gumminess values whilst the gels prepared at 350 rpm had the lowest values for these parameters. Maxwell parameters showed that with increasing mixing speed and heating time, starch gels became smoother due to the depolymererisation of starch biopolymers as confirmed by intrinsic viscosity results. SEM images indicated that with increasing time and speed of mixing, air cells of sponge-like structures became larger. The results showed that the mixing speed and time determine the final textural properties of corn starch gels and therefore, to achieve optimum product consistency, it is required to control these two factors during starch pasting.