Deodorization of food-related nuisances from a refrigerator: The feasibility test of photocatalytic system

The effectiveness of the TiO₂-UV LED system for the deodorization of food-related nuisances was evaluated by both instrumental analysis and human sensory test. Emission characteristics of volatile odorants were also investigated using the two refrigerator system (control and treatment unit) filled with 10types of food samples (raw beef, raw chicken, spam, onions, tomatoes, strawberries, boiled eggs, codfish, mackerel, and French cheese). The odorant samples collected at seven different periods (0, 3, 6, 9, 24, 72, and 120h) up to 5days were collected and analyzed. The average removal rates of sulfur compounds (H₂S, CH₃SH, DMS, and DMDS), styrene, isobutyl alcohol, and TMA were fairly high in the range of 75.2-94.2%, while CS₂, benzene, and MIBK were not removed effectively by the photocatalytic system. In light of the sensory test, the dilution-to-threshold ratio (D/T ratio) values were also evaluated in reference to odor intensity (OI) and odor activity value (OAV). In control unit, DMS, NH₃, and TMA were dominant in terms of OI, control unit, while H₂S, CH₃SH, and TMA were in terms of OAV. Despite some limitations, the photocatalytic system tested in this study was effective in removing most of these key odorants (75-94%).