不同温度段苹果枝木醋液化学组成、抑菌及抗氧化活性比较

Comparison of Chemical Compositions,Antimicrobial and Antioxidant Activities of Pyroligneous Acids of Apple Branches

以苹果枝为原料,采用干馏法分3个温度段收集苹果枝木醋液。用GC-MS法分析各温度段苹果枝木醋液的有机成分,并对木醋液的抑菌活性和抗氧化活性进行测定。结果表明:3个温度段苹果枝木醋液的化学组成不同,含量差别较大,低温度段(100～200℃,AP1)中检出45种物质,占整个出峰面积的91.26%,其中酚类含量为51.33%,有机酸酸含量为18.50%,酮类含量为8.98%,呋喃类含量为7.23%;中间温度段(200～310℃,AP2)检出47种物质,占整个出峰面积的95.35%,其中酚类含量为24.69%,有机酸酸含量为40.05%,酮类含量为7.52%,呋喃类含量为12.81%;高温度段(310～500℃,AP3)检出47种物质,占整个出峰面积的93.00%,其上述物质含量依次为34.66%,28.37%,12.49%和6.93%。有机酸在中间温度段木醋液中含量最多,酚类在低温度段含量最多。3个温度段的苹果枝木醋液均有抑菌和抗氧化活性,其抑菌活性顺序为AP2>AP3>AP1,AP2的抑菌活性最强,且与AP1和AP3的差异显著,其中对植物病原菌的EC50为2.43～5.27Mg·mL-1;抗氧化活性大小顺序为AP1>AP3>AP2,且存在显著的量效关系,AP1的抗氧化活性最强,均高于抗坏血酸和BHT。初步分析AP2较强的抑菌活性和AP1较强的抗氧化活性分别与其中高含量的有机酸和酚类物质有关。

Pyroligneous acids were prepared throngh pyrolysis of apple tree branch at 3 temperature ranges.Chemical components of the pyroligneous acids were analyzed with GC-MS.Antimicrobial and antioxidant activities of the acids were tested.The results showed that pyroligneous acids derived with 3 temperature ranges were slightly different in chemical compositions,but significantly different in the contents of each chemical component.A total 45 compounds were identified from the pyroligneous acid collected from lower temperature range,100-200 ℃（AP1）,accounting for 91.26% of the total peak area.Phenols,organic acids,ketones,and furan derivatives in the pyroligeneous acids accounted for 51.33%,18.50%,8.98%,and 7.23%,respectively.A total 47 compounds were identified from the middle temperature range,200-310 ℃（AP2）,accounting for 95.35% of the total peak area.Their phenols,organic acids,ketones,and furan derivatives accounted for 24.69%,40.05%,7.52%,and 12.81%,respectively.The pyroligneous acids from the high temperature range,310-500 ℃（AP3）,had 47 compounds identified,accounting for 93.00% of the total peak area.Their phenols,organic acids,ketones,and furan derivatives accounted for 34.66%,28.37%,12.49%,and 6.93%,respectively.Organic acids had the highest content in AP2,while phenols had the highest content in AP1.All the pyroligneous acids from 3 temperature ranges exhibited antimicrobial and antioxidant activities,with different strengths.The antimicrobial activities of three pyroligneous acids were in an order of AP2〉AP3〉AP1.AP 2 exhibited the strongest antimicrobial activity,significantly different from AP3 and AP1,and the range of EC_ 50 to plant pathogens was 2.43- 5.27 mg·mL-1.Antioxidant activities of three pyroligneous acids were all higher than those of BHT and ascorbic acid,and were in an order of AP1〉AP3〉AP2.There existed a significant dose-effect relationship in the antioxidant activity.High antimicrobial activity of AP2 and high antioxidant activity of AP1 might be related to their high contents of organic acids and phenolic compounds respectively.