麻竹笋笋壳醋酸木质素结构特性及抗氧化性

Structural Characteristics and Antioxidant Activities of Acetic Acid Lignin from Bamboo Shell

采用醋酸法提取大叶麻竹笋笋壳中木质素,并对得到的醋酸木质素进行表面微观特性、结晶特性、热稳定性、吸湿特性及抗氧化能力测定,同时与相同来源的纤维残渣和粗膳食纤维进行对比实验。结果表明,醋酸木质素表面呈球形且结构粗糙多孔,以无定形结构存在,热稳定性较好,最大失重速率为0.34%/℃,吸湿率较低(5.21%)。DPPH自由基清除能力和亚铁离子还原能力(FRAP)测定结果表明,醋酸木质素抗氧化能力高于人工合成的抗氧化剂BHT,其ABTS自由基清除能力与BHT相当,无显著差异。并且醋酸木质素的抗氧化能力显著高于相同来源的纤维残渣和粗膳食纤维。

Lignin was extracted from bamboo（ Dendrocalamus latiforus Munro） shoot shell by acetosolv process. The surface microscopic characteristic,crystalline characteristic,thermostability,moistureabsorbing characteristic and antioxidant activities of acetic acid lignin（ AL） were investigated and compared with that of the same source of cellulose residue and coarse dietary fiber. The results showed that the surface of AL was spherical,coarse and porous. The amorphous acetic acid lignin had better thermal stability and the maximum weight loss rate was 0. 34%/℃ with a low moisture absorption（ 5. 21%）. In terms of the DPPH radical scavenging activity and ferric reducing antioxidant power（ FRAP）,AL showed stronger antioxidant activity than the commercial synthetic antioxidant BHT. But there was no significant difference in the ABTS free radical scavenging capacity between AL and BHT.The antioxidant capacity of AL was significantly higher than that of the same source of cellulose residue coarse dietary fiber.