kappa-Carrageenan gels prepared with various carrageenan concentrations in pure water were completely dried and then swelled in pure water. Photon transmission measurements were performed using a UV-Vis (UVV) spectrometer during the swelling of kappa-carrageenan gels. Transmitted photon intensity, I-tr, increased exponentially as swelling time is increased for all gel samples. The behaviour of I-tr was interpreted by Monte-Carlo Simulation. The increase in I-tr was quantified by employing Li-Tanaka equation, from which time constants tau(l) and collective diffusion coefficients, D-O were determined for the gels in various carrageenan concentrations. Gravimetric and volumetric measurements were also carried out during swelling of gels. It is observed that gel with high carrageenan content possess more double helices and more lattice dislocations and swell slower than gels with low carrageenan content which may contain less double helices and less lattice imperfections. Increase in I-tr was interpreted by the homogeneous distribution of double helices in the carrageenan gel system. (C) 2003 Elsevier B.V. All rights reserved.