To preserve the high anti-oxidant activity of resveratrol for a long period of time, porous particles were utilized. The porosity of these substrate particles was controlled by DVB content and toluene/heptane ratios in the seeded polymerization. The influence of porosity on the anti-oxidant activity of the immobilized resveratrol was investigated. From SEM and CLSM analysis, it was confirmed that the resveratrol was stabilized in the porous particles after the immobilization process. The resveratrol has a crystalline structure, which was maintained even after immobilization; however, the resveratrol exhibited an amorphous form in the case of the smallest pore size and the highest specific surface area. Although the loading capacity of resveratrol was largely affected by the hydrophobicity and the specific surface area of porous particles, the anti-oxidant activity of immobilized resveratrol was preserved in over 93% in comparison to the raw resveratrol. In addition, the bioactivity of resveratrol immobilized in the porous particles was sustained for 5 weeks. (c) 2005 Elsevier Ltd. All rights reserved.