Effect of Extraction Solvent on the Ultrasound-Assisted Enzymatic Hydrolysis of Extraction Residue of Ceylon Olive (Elaeocarpus Serratus L.) Leaves

萃取溶劑對錫蘭橄欖（Elaeocarpus Serratus L.）葉萃餘物超音波輔助酵素水解之效應

陳潁軒(Ying-Hsuan Chen) ； 楊珺堯(Chun-Yao Yang)

《臺灣農業化學與食品科學》 57卷3期 (2019/06) Pp. 143-153

https://doi.org/10.6578/TJACFS.201906_57(3).0004

摘要

The ultrasound-assisted enzymatic hydrolysis of extraction residues from Ceylon olive (Elaeocarpus serratus L.) leaves after solvent extraction was investigated in this study, and the fermentable sugars were produced for the valorization of the extraction residues. The effect of types of extraction solvent on the structure and enzymatic hydrolysis of the extraction residue was explored. The analysis for the functional groups and the crystallinity of the leaves before and after solvent extraction was performed. The morphological structure and elemental changes of the extraction residues before and after the enzymatic hydrolysis were observed and analyzed. The total reducing sugars (TRS) production of enzymatic hydrolysis of the extraction residue was measured with or without ultrasound. Using 95% ethanol as the extraction solvent, the ratio in crystallinity increase of the extraction residue was the largest (44.15%), thus facilitating the reaction of enzymatic hydrolysis. Using the extraction residue from 95% ethanol extraction as the substrate in 4 hour of enzymatic hydrolysis with ultrasound (40 kHz/300 W) at 50°C, the high TRS production was obtained as 121.35 mg/g-extraction-residue, which was 2.65 times of that (45.74 mg/g-extraction-residue) using the extraction residue from water extraction with shaking (120 rpm), displaying that the ultrasound was able to greatly enhance the efficiency of enzymatic hydrolysis of the solid substrates. Besides, the kinetic model with two parameters by considering the impeded effect in a heterogeneous system was used to describe the enzymatic hydrolysis of the solid substrate, and the initial observed rate coefficient and the deactivation coefficient for different extraction residues were correlated from nonlinear regression. In this study, the effective method to produce the reducing sugars from the extraction residue of Ceylon olive leaves is provided, and the produced fermentable sugars can be separated for further use.

關鍵字

Ceylon olive leaf ； Ultrasound ； Enzymatic hydrolysis ； Extraction solvent

並列摘要

本研究探討錫蘭橄欖（Elaeocarpus serratus L.）葉經溶劑萃取後的萃餘物之超音波輔助酵素水解反應來生產可發酵糖，以提升萃餘物之利用價值。本研究深入探索萃取溶劑種類對萃餘物結構及其酵素水解之影響，進行葉子在溶劑萃取前後之官能基與結晶度變化之分析，觀察葉子萃餘物在酵素水解前後之形態結構及分析元素比例的改變，量測葉子萃餘物在有無使用超音波之酵素水解的總還原糖（TRS）產量。結果顯示，使用95%乙醇之溶劑萃取可得萃餘物之最大結晶度增加率（44.15%），因此有利於酵素水解反應。使用95%乙醇萃取之萃餘物為基質，在超音波（40kHz/300W）於50oC經4小時酵素水解反應，可得高TRS產量為121.35mg/g-extraction-residue，其為使用水萃取後之萃餘物在震盪攪拌（120rpm）下TRS產量（45.74mg/g-extraction-residue）的2.65倍，顯示超音波能大幅促進固體基質的酵素水解效率。此外，本研究以非勻相系統考量阻礙效應的雙參數動力學模式來描述固體基質之酵素水解反應，並由非線性迴歸獲得不同萃餘物的酵素水解初始觀測速率係數與衰退係數。本研究提供以錫蘭橄欖葉萃餘物生產還原糖之有效方法，其產生之可發酵糖經分離後可進一步利用。

並列關鍵字

錫蘭橄欖葉 ； 超音波 ； 酵素水解 ； 萃取溶劑