JOURNAL OF FOOD PROCESS ENGINEERING, cilt.34, sa.1, ss.108-124, 2011 (SCI-Expanded)
Adsorption of dark colored compounds onto adsorbent resin was studied for different adsorbent resin concentrations (1.5, 2.0, 3.0, 5.0, 10.0, 15.0 g resin/L apple juice) and different degrees Brix ratios of apple juice (10, 20, 30 degrees Brix). The equilibrium data obtained fitted well to Langmuir isotherm. The maximum adsorption capacity was found 0.124 1/g resin at 30C for apple juice having a degrees Brix ratio of 10. The adsorption of dark colored compounds from apple juice onto adsorbent resin followed pseudo-second-order kinetic model. The adsorption rate constants decreased as the degrees Brix ratio of apple juice increased. As it was confirmed by Bangham's equation, the rate-limiting step was intraparticle diffusion. This study showed that using adsorbent resin to improve color had no effect on organic acid and sugar composition of apple juice.