前處理對木質纖維素生物質防曬效果之影響

Abstract

本研究旨在探討不同木質纖維素生物質經過不同前處理，其化學組成成分、木質素含量、粒徑大小與防曬效果之間的關係，用以評估經過前處理之木質纖維素生物質作為防曬成分的潛力。本實驗將木質纖維素生物質材料柳杉樹皮木粉（CJB）及台灣櫸心材木粉（ZSHW）進行亞氯酸鹽法去木質素、硫酸水解及纖維素酶水解，並將柳杉樹皮木粉、台灣櫸心材木粉及黃檗樹皮木粉（PCB）以熱水萃取製得熱水萃取液。將上述處理後的木質纖維素生物質顆粒及熱水萃取液進行粒徑分布分析及紫外線（UV）吸收值測試。 研究結果顯示，經過亞氯酸鹽法去木質素後，木質纖維素生物質可以透過硫酸水解或纖維素酶水解減小粒徑，並提升紫外線吸收值。木質素含量在20%至45%時，木質素含量對紫外線吸收值的影響較大，木質素含量越高，紫外線吸收值及防曬係數（SPF）值越高。反之，木質素含量在10%以下時，粒徑大小對紫外線吸收值的影響較大，粒徑越小，紫外線吸收值及防曬係數值越高。 經過前處理之木質纖維素生物質顆粒，其防曬係數值可由未處理之1.34提升至5.08，可達到同等重量二氧化鈦（TiO2）防曬係數值的17.99%。木質纖維素生物質之熱水萃取液也有良好的防曬係數值，尤其是黃檗樹皮木粉之熱水萃取液，其防曬係數值為22.40，可達到同等重量二氧化鈦防曬係數值的79.37%。因此，經過本研究前處理的木質纖維素生物質顆粒及其熱水萃取液皆有應用於防曬成分的潛力。

This study investigates the relationship between the chemical composition, lignin content, particle size and sun-blocking property of various lignocellulosic biomass after different pretreatments. In this study, the wood flour of bark of Cryptomeria japonica (CJB) and the wood flour of heartwood of Zelkova serrata (ZSHW) were subjected to acidified sodium chlorite method delignification, sulfuric acid hydrolysis and cellulase hydrolysis. CJB, ZSHW and the wood flour of bark of Phellodendron chinense (PCB) were subjected to hot water extraction to obtain the hot water extracts. Particle size distribution analysis and the UV absorbance test of pretreated biomass particles and hot water extracts were conducted. Result shows that after delignification by acidified sodium chlorite method, the particle size of lignocellulosic biomass decreased and the UV absorbance value increased by sulfuric acid hydrolysis or cellulase hydrolysis. When the lignin content was about 20% to 45%, the lignin content had a greater impact on the UV absorbance value. The higher the lignin content, the higher the UV absorbance value and SPF value were demonstrated. On the contrary, when the lignin content was below 10%, the particle size had a greater impact on the UV absorbance value. The smaller the particle size, the higher the UV absorbance value and SPF value will be. SPF values of lignocellulosic biomass particle increased from 1.34 to 5.08 after pretreatments, can reach 17.99% of weight based SPF value of titanium dioxide (TiO2). Hot water extracts from lignocellulosic biomass also have great UV absorbance value, especially the hot water extract from PCB. Its SPF value is 22.40, able to reach 79.37% of weight based SPF value of TiO2. Therefore, both the lignocellulosic biomass particles and hot water extracts in this study have the potential to be applied to sunscreen agents.