Synergistic Effects of the Five Components from Essential Oils on Mold-resistance of Paper

• Main Authors: Yin-Jue Chang, 張銀珏
• Other Authors: Shang-Tzen Chang
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/88808635747820904955

碩士 === 國立臺灣大學 === 森林環境暨資源學研究所 === 105 === In this study, the anti-mold activities against Aspergillus niger of five components from plant essential oils, including cavacrol (Car), cinnamaldehyde (Cin), eugenol (Eug), geraniol (Ger) and thymol (Thy), and their binary combinations in three mixing ratio (1:3, 1:1, 3:1) were investigated. First of all, three methods, including agar dilution, direct contact and fumigation, were employed to determine the minimal inhibitory concentration (MIC) of each component, separately. Then, the isobologram analysis, combination index (CI) and dose reduction analysis were used to quantify the synergy and the variation in dose of each combination. The inhibitory and fungicidal effects of synergistic combinations against spores of common molds, A. niger, A. terreus and Penicillium citrinum, on paper were evaluated. Finally, the changes in properties of paper of the best formulations were also determined. According to the result of agar dilution method, carvacrol and thymol not only presented the excellent activities (MIC = 200 μg/mL) to inhibit the growth of mycelium of A. niger among these components, but also showed synergistic effects while they combined in all three ratios. These combinations could reduce 40 to 80% dose than individual. From the results of both direct contact and fumigation methods, cinnamaldehyde and thymol have the excellent activities in both methods (MIC = 100 μg/cm2, 40 mg/L), and carvacrol only has the excellent activity in the fumigation method (MIC = 40 mg/L). From the results of direct contact method, the treatment of Cin-Eug (3:1) and Cin-Ger (3:1) of paper showed the strongest synergistic effect (CI = 0.7), while the CIs of the others were 0.8; the treatment of Cin-Ger (3:1) showed the lowest minimal inhibitory dose (MID = 88 μg/cm2). From the results obtained from the fumigation method, the synergies of all synergistic formulations were equal (CI = 0.8), while the lowest MID were presented by Car-Thy (1:3), Car-Thy (1:1) and Car-Thy (3:1) (MID = 32 mg/L). According to the results of inhibitory and fungicidal effects of synergistic formulations against common mold spores on paper, the treatment of Cin-Eug (3:1) and Cin-Ger (3:1) for paper could kill the three mold spores. Although, the mechanical properties of filter papers might be slightly decreased by the treatment of Cin-Eug (3:1) and Cin-Ger (3:1), the properties of Xuan papers and wood-free papers would not change after contacted with treated papers. In conclusion, Cin-Ger (3:1) is a low dose formulation with fungicidal effect against common mold spores, and avoids affecting the properties of treated papers.