A study of diffusion of dyes in model foods using a visual method

► The diffusion of dyes in gels was visualised in situ for 10 min. ► Agar and alginate gels were used with rhodamine 6G and methylene blue dyes. ► Experiments were performed at 30, 50, and 70 °C and 0, 167, 333, 500, 667 V m−1. ► Limitations of Fickian analysis led to the penetration model for data analysis. ► Gel, gel/salt concentration, dye charge/mass, electric field effects were examined.