高温油热处理对竹材淀粉含量及防霉性能的影响

Effect of high temperature oil heat treatment on the starch content and mold-resistant property of bamboo

为了探索高温油热处理改性工艺对5年生新鲜毛竹材淀粉含量及防霉性能的影响,研究采用甲基硅油为加热介质,在不同热处理时间(2,4和6 h)和不同热处理温度(140,160,180和200℃)条件下对毛竹进行高温油热处理。利用分光光度计法测量竹材中的淀粉含量,采用扫描电子显微镜(SEM)观察热处理前后竹材微观结构变化,同时对比了不同油热处理工艺下竹材的防霉效果。试验结果表明:未处理竹材的淀粉含量为3.16%,经过油热处理的竹材淀粉含量均少于未处理竹材,且淀粉含量随着油热处理温度和时间的增加而逐渐降低。在200℃、6 h油热处理条件下,处理后竹材的淀粉含量为0.09%,相比于未处理竹材下降97.23%,高温油热处理能够有效降低竹材中淀粉含量;通过SEM观察发现高温油热处理后竹材薄壁细胞组织发生变形破裂,竹材的渗透性提高,细胞腔中淀粉颗粒显著减少,且竹材纹孔及表面有油介质附着提高防霉性能;在竹材防霉试验中,经过油热处理竹材的防霉能力与未处理材相比均有提高。当热处理温度大于160℃时,防霉效果显著,且竹材淀粉含量越低,对霉菌的防霉效果越好。

In order to explore the related effect of high temperature oil heat treatment modification process on the starch content and mold resistance property of 5 year old moso bamboo,in this study,methyl silicone oil was used as the heating medium,and high temperature oil heat treatment was carried out to treat the bamboo under different heat treatment times(2,4 and 6 h)and different heat treatment temperatures(140,160,180 and 200℃).In this experiment,the starch content in the bamboo before and after the oil heat treatment was mainly measured by the spectrophotometer,and the change rule was fully analyzed.The scanning electron microscope(SEM)was used to observe the changes of the microstructure and starch content of the bamboo before and after the oil heat treatment.At the same time,through the bamboo mold prevention experiment to observe the anti-mildew effect of the bamboo under different oil heat treatment processes,and explore the mold mechanism by combining the changes of starch content.The experimental results showed that the starch content of the untreated bamboo was 3.16%,while the starch content of the bamboo after the oil heat treatment was smaller than that of the untreated bamboo.Moreover,the starch content of the treated bamboo gradually decreased with the increase of the oil heat treatment temperature and time.Among them,under the condition of the oil heat treatment at 200℃for 6 h,the starch content of the treated bamboo was 0.09%,which was 97.23%lower than that of the untreated bamboo.These indicated that the high temperature oil heat treatment could effectively reduce the starch content in the bamboo.Through the SEM examination,it was found that the parenchyma cells of bamboo were deformed and broken after the heat treatment of high-temperature oil,thereby improving the permeability of the bamboo,so that the high-temperature oil medium entered the cell cavity,the starch particles were significantly reduced,and bamboo pits and surfaces were attached by oil medium to improve the mold resistance property.In the bamboo mold prevention experiment,the mold resistance property of the oil-treated bamboo was improved compared with the untreated bamboo.When the heat treatment temperature was higher than 160℃,the mold resistance was remarkable.The lower the starch content of bamboo,the better the resistance on mold was obtained.