EFFECT OF UV IRRADIATION ON STORAGE OF RIVIERA OLIVE OIL IN GLASS BOTTLES COATED WITH BNNSS/PVB MULTILAYER THIN FILM

Abstract

UV absorbers are used to reduce the harmful effects of UV rays and to ensure that the properties of the materials are adequately protected. To protect against UV rays, one of the UV absorber molecules can reduce the combined energy of radiation to thermal energy that provides less energy in a photophysical process. Inorganic materials such as metal oxide semiconductors can effectively absorb UV irradiation and exhibit good heat-resistance properties. TiO2, CeO2, and ZnO are inorganic compounds with UV protective properties. Since some of these compounds are colored, their use is limited. Boron nitride nanosheets (BNNSs) are alternative UV inhibitors to these inorganic compounds. In this study (BNNSs)/PVB multilayer thin films were produced for the protection of glass packages using the dip-coating method. Riviera olive oil (RO-oil) samples in the both coated and uncoated bottle were exposed to UV irradiation for different times (75, 170, 360 and 720 hours). After the UV irradiation at different times, the total phenol and antioxidant contents in RO-oil were determined by Folin Ciacalteu and DPPH methods. The color change of RO-oil after UV irradiation was determined by UV visible spectrophotometer. Specific absorption coefficients K232 and K270 (specific extinction) in the ultraviolet region were measured for estimating the oxidation stage of RO-oil after degradation. Free fatty acid (FFA) of RO-oil after UV irradiation was determined by the titration method. According to the results of the analysis, the acidity values of RO-oil were preserved 20 times compared to the uncoated glass bottle after 720 hours UV. BNNSs/PVB coating was also effective in preserving total phenol, antioxidant contents and oxidation state of RO-oils under long term UV irradiation.