Influence of selected storage temperatures on wood properties and its biological resistance after the use of methylxanthines

Methylxanthine’s fungicidal properties were investigated, with attention to the temperature of treatment. Caffeine and theophylline treatments of beech and spruce woods were applied for three months in the temperature range of -20 to 40 °C, simulating potential weather conditions in the European region and temperatures specific for various wood applications (cellars, wine cellars, room indoor temperatures, interior trusses). Effects of the selected temperatures were considered without the influence of the other possible factors, which have been considered in previous studies (e.g. effects of temperature in combination with other factors such as UV radiation, humidity, and chemical or biological degradation). Then, the specimens were exposed to a mix of molds and fungi for three months under controlled laboratory conditions in order to analyze a possible subsequent biological attack. The results did not show any effect of temperature of the methylxanthine treatment within the studied range on the organismal activity. Caffeine exhibited a better protective potential than theophylline and was more effective for spruce than for beech. The results indicated the suitability of caffeine for protection of spruce and spruce-based materials in interior applications at a stable temperature without significant effects of UV and humidity.