Bamboo materials contain a large amount of starch,protein,and sugars,which are essential nutrients for the growth of mildew,causing bamboo and its products to be susceptible to mildew contamination and eventually losing their value and being discarded.This results in a significant waste of resources and economic losses,hindering the high-quality development of the bamboo industry to some extent.At present,the issues of mildew and mildew prevention in bamboo materials have received much attention and research,including the study of environmentally friendly,natural antimildew agents,which have gained significant attention and have gradually become a research hotspot.Phenolic extracts from traditional Chinese medicine are natural antimildew agents that possess good environmental performance,broad-spectrum antimildew properties,and high antimildew activity.They have broad research and application prospects in the field of bamboo material mildew prevention.Therefore,this thesis takes eugenol,Carvatrol,and paeonol as the research objects to investigate their antimildew properties and mechanisms on common bamboo mildew species such as Penicillium citrinum,Trichoderma viride,and Aspergillus niger.The best-performing extract was used to prevent mildew on planed thin bamboo,and the mildew prevention mechanism and performance were discussed.The main results and conclusions are as follows:(1)The Oxford Cup method and the double dilution method were used to study the antimildew effects and mechanisms of eugenol,Carvatrol,and paeonol on bamboo mildew.The results showed that all three phenolic substances had antibacterial effects,with carvacrol showing the strongest antimildew activity,with minimum inhibitory concentration(MIC)and minimum fungicidal concentration(MFC)values of 1.56 mg/m L and 1.76 mg/m L,respectively,followed by eugenol and paeonol.At a concentration of 25 mg/m L,eugenol and apiole both had an inhibition rate of more than50% against various mildews.In addition,the three phenolic substances at different concentrations can destroy the mycelial morphology and structural integrity of mildews,and the degree of damage increases with the concentration and treatment time.At the same time,they also have a certain impact on the extracellular p H value of molds.(2)The single-factor method and orthogonal test method were used to explore the process of Carvatrol mildew prevention treatment on planed thin bamboo and the mildew prevention performance of Carvatrol-treated planed thin bamboo.The results show that the optimal process parameters for Carvatrol mildew prevention treatment on planed thin bamboo are: planed thin bamboo size of 350 mm × 350 mm,immersion time of 2.5 hours,and Carvatrol concentration of29.25 mg/m L.Among these,Carvatrol concentration is the main factor affecting the mildew prevention performance of the treated planed thin bamboo.When the Carvatrol concentration reached29.25 mg/m L,the mildew prevention levels of Penicillium citrinum,Trichoderma viride,and Aspergillus niger reached grade 0(strong mildew prevention)and grade 1 for mixed mildews.(3)The efficacy of compound phenolic substances in preventing and controlling mildews was studied,specifically investigating the antimildew effects of eugenol and carvacrol compound in a ratio of 2:1,1:1,and 1:2 on sliced bamboo vaneers.The results showed that the antimildew properties of PC,TV,and MM were enhanced to varying degrees when eugenol and carvacrol were compounded in a ratio of 1:2 and used to treat sliced bamboo vaneers,indicating that compound phenolic substances could achieve more effective prevention and control of mildews.At the same time,comparative analysis of FT-IR spectra revealed that the chemical structure of the sliced bamboo veneers treated with a complexing agent and that treated solely with carvacrol had little difference. |