TY - JOUR TI - Effect of controlled release of tocopherol on lipid oxidation DO - https://doi.org/doi:10.7282/T3S75FCV PY - 2012 AB - Lipid oxidation is one of the major problems affecting the shelf life of fatty foods. Controlled release packaging (CRP) is an innovative packaging technology that incorporates antioxidants into packaging materials and releases them in a controlled manner to food products thus providing continuous replenishment of antioxidants to food. The objective of this research is to study the release behaviors of tocopherol (antioxidant) in CRP films and simulate these release behaviors with different initial concentrations to examine the effect of controlled release of tocopherol on lipid oxidation. Low density polyethylene (LDPE), polypropylene (PP) and LDPE/PP blend films were manufactured by extrusion process to contain 3000 ppm of tocopherol. Release behaviors of tocopherol in the package films were studied and diffusivity values of tocopherol in above three films were estimated from the release study at different temperatures, which ranged from 2.04*10-16 m2/s to 2.39*10-13 m2/s. Release profiles of tocopherol from LDPE and LDPE/PP films were simulated in a syringe pump using estimated diffusivities and two initial tocopherol concentrations (100 and 300 ppm) to inhibit lipid oxidation of linoleic acid at 40 ÂșC. The induction period of lipid oxidation was determined to evaluate the antioxidant effectiveness of tocopherol with different release profiles. Induction period changed significantly with controlled release compared to instant addition. For releasing of 100 ppm tocopherol, release by DLDPE, the induction period was 73 hours, longer than that of instant addition (57 hours). For releasing by DLDPE/PP, the induction period was 47 hours, shorter than instant addition. For releasing of 300 ppm tocopherol, release by DLDPE, the induction period (213 hours) was twice of that from instant addition (91 hours). This work demonstrated that controlled release of tocopherol from CRP films has great impact on induction period extension of lipid oxidation. Less tocopherol can be applied to achieve longer induction period compare to instant addition. However, too slow diffusion of tocopherol in certain polymer may not have the effect to prevent lipid oxidation. This work provides partial quantitative information to help researchers and packaging manufacturers select suitable initial concentration and polymer types based on required shelf life. KW - Food Science KW - Lipids--Research KW - Controlled release technology KW - Food--Preservation KW - Food--Vitamin E content LA - eng ER -