Antifungal activity of TiO2 photocatalysis against Penicillium expansum in vitro and in fruit tests

• Published in: International journal of food microbiology Vol. 107; no. 2; pp. 99 - 103
• Main Authors: Maneerat, C, Hayata, Y
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 15.03.2006
• Subjects: airborne microorganisms; Antifungal Agents - pharmacology; antifungal properties; Biological and medical sciences; catalysts; coatings; Colony Count, Microbial; decontamination; Dose-Response Relationship, Drug; food contamination; Food industries; Food Microbiology; food pathogens; food preservation; Food Preservation - methods; food surfaces; Fruit - microbiology; Fruit and vegetable industries; fruits (food); Fundamental and applied biological sciences. Psychology; Germination; in vitro studies; packaging materials; Penicillium - drug effects; Penicillium - growth & development; Penicillium - physiology; Penicillium expansum; photochemical reactions; Photosensitizing Agents - pharmacology; plastic film; postharvest diseases; Spores, Fungal - drug effects; Spores, Fungal - growth & development; Time Factors; Titanium - pharmacology; titanium dioxide; vegetables; Fungi; Penicillium expansum; Antifungal agent; Fruit; Film; TiO2 photocatalytic reaction; Fungi Imperfecti; TiO2-coated film; In vitro; Thallophyta
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2005.08.018

The antifungal activity of TiO2 photocatalytic reaction in the form of TiO2 powder and TiO2 coated on a plastic film against Penicillium expansum was investigated in vitro and in fruit tests. The mixture of P. expansum conidial suspension and TiO2 powder was added to potato dextrose agar (PDA) plates for vitro test. The TiO2 photocatalytic reaction reduced conidial germination of the fungal pathogen. It was found that the ability of the TiO2 photocatalytic reaction to suppress P. expansum growth correlated to the amount of TiO2 added. Lower numbers of viable colonies of P. expansum were observed with increasing amount of TiO2. Regardless of the kind of selected fruit inoculated with P. expansum, both TiO2 powder and TiO2-coated film exhibited antifungal activity to control fruit rot. Development of Penicillium rot in apple was significantly (P = 0.05) retarded by the TiO2 photocatalytic reaction. Similarly the TiO2 photocatalytic reaction was the only treatment where no tomato fruit rot was noticeable after 1 week of storage. TiO2-coated film also decreased brown lesions and Penicillium rot infection in lemons. The mean severity fruit rot scores (browning and softening flesh) were 3.2 and 1.9 for uncoated and TiO2-coated film, respectively. Our findings suggest that “TiO2 photocatalytic reaction” shows antifungal activity against P. expansum which may have potential for postharvest disease control.