甘蔗不同组织中游离态和结合态酚酸的分布及抗氧化活性

Distribution and Antioxidant Activity of Free and Bound Phenolic Acids in Sugarcane Tissues

摘要:

为了探讨甘蔗不同组织中酚酸的存在形式，本文利用反相高效液相色谱法（RP-HPLC）对蔗汁、蔗叶及蔗渣三个组织中游离态和结合态的酚酸进行了定性和定量检测分析。结果表明，甘蔗组织中的酚酸主要以结合态形式存在，但其在甘蔗三个组织中的含量和存在形式有差别。甘蔗叶、蔗渣中游离的酚酸含量最高，蔗汁较低。蔗汁、蔗叶及蔗渣中总游离态酚酸含量分别为317.18 mg/kg（干固物），1568.37 mg/kg（干基）及1504.57 mg/kg（干基）；总结合态酚酸含量分别为740.32 mg/kg（干固物），2725.41 mg/kg（干基），2452.13 mg/kg（干基）。在蔗汁中，咖啡酸、没食子酸主要以游离态存在，阿魏酸、香豆酸主要以结合态存在，而在蔗叶和蔗渣中，咖啡酸、阿魏酸、香豆酸主要以结合态形式存在。甘蔗不同组织中游离态酚酸的DPPH和ABTS自由基清除活性优于结合态酚酸，不同组织中的游离态酚酸和结合态酚酸含量分别与抗氧化活性呈正相关性。

Abstract:

In order to explore the different forms of phenolic acids in the tissues of sugarcane, qualitative and quantitative analyses of free and bound phenolic acids in the cane juice, leaves, and bagasse of sugarcane were performed using reversed-phase high-performance liquid chromatography (RP-HPLC). The results showed that phenolic acids primarily existed in the bound form in sugarcane; however, the content and form were different in the three different tissues. The leaves and bagasse had higher phenolic acid content than cane juice. The free phenolic acid content in cane juice, leaves, and bagasse was 317.18 mg/kg (dry solids), 1568.37 mg/kg (dry basis), and 1504.57 mg/kg (dry basis), respectively. The bound phenolic acid content in cane juice, leaves and bagasse was 740.32 mg/kg (dry solids), 2725.41 mg/kg (dry basis), and 2452.13 mg/kg (dry basis). In cane juice, caffeic acid and gallic acid were primarily in the free form, whereas ferulic acid and coumaric acid were primarily in the bound form. Caffeic acid, ferulic acid, and coumaric acid were primarily in the bound form in cane leaves and bagasse. In the different sugarcane tissues, free phenolic acids exhibited better free-radical removal activities towards DPPH and ABTS than bound phenolic acids. The free and bound phenolic acid content in sugarcane tissues was positively correlated with antioxidant activity.