Evaluation of Active Packaging based on PET Containing ZnO and TiO2 Nanoparticles on Mayonnaise Shelf-Life

In food industries, nanotechnology can potentially provide solutions to food packaging with short shelf life. Nowadays, there has been an increasing interest in nanocomposites for many advantages in food packaging. Polymers have a wide range of applications in food packaging, and many studies have been conducted on the simultaneous use of nanoparticles and polymers in food packaging, which can be attributed to the synergistic effect of these nanoparticles. One of the most important goals is to increase the safety and quality of food during storage, transportation and protection against adverse factors such as chemical, moisture, light and external forces. The aim of this study was to investigate the effect of film prepared from PET containing nanoparticles of ZnO, TiO2 and TiO2 + ZnO nanoparticles in quantities 0.25, 2 and 2.25%. Weight is based on the physicochemical properties of mayonnaise.

The PET-based nanocomposites containing 2% by weight of TiO2 nanoparticles and 0.25% by weight of ZnO nanoparticles were prepared by melt mixing using an extruder. Mixtures of PET nanoparticles were dried in the oven at 170 ° C before loading in the extruder and fed simultaneously from the feeder to the extruder. The material was melted and thoroughly mixed as it passed through the extruder. The melt from the extruder was cooled by passing through a pool of cold water and entered the granule mill to make granules. Pure PET samples were molded as control and PET-based preforms containing nanoparticles. At the end of the molding stage, chillers were used to cool the preforms. PET-based bottles containing nanoparticles were produced by blowing preforms at appropriate temperatures and pressures for 120 to 140 seconds. The morphology and particle size of the bottle layers were investigated using FE-SEM. Then physicochemical properties including colorimetry, pH and acidity of mayonnaise, oxidative and peroxide stability, acidity of the extracted oil and migration of Zn +2 and Ti +2 ions from mayonnaise during 90 days at room temperature (22 ± 2 ° C) Celsius) was examined.

Based on FE-SEM images, the films of polymer bottles containing ZnO and TiO2 nanoparticles showed a smoother surface than the films of polymer bottles of ZnO + TiO2 nanoparticles. Moreover, the results of physicochemical properties showed that the reduction of brightness index as well as pH, acidity number, peroxide number and oxidative stability of mayonnaise sample during 90 days of storage in a bottle containing nanoparticles had a significant decrease compared to the control sample. According to the results of the present study, mayonnaise shelf life indices can be increased.

Due to the importance of food emulsions such as mayonnaise, it is necessary to pay attention to the quality characteristics and shelf life of this popular condiment. The use of these nanocomposites could be a promising approach to creating new active packaging in the food industry.