菠萝叶片色泽、色素及抗氧化活性的关系

以菠萝22个栽培品种的叶片为实验材料,测定其5种色泽参数（L^*、a^*、b^*、c^*和h^*值）、5种色素（叶绿素、类胡萝卜素、花青苷、类黄酮和总酚）含量及3种抗氧化活性指标（ABTS、DPPH自由基和亚硝酸盐的清除能力）,并进行相关性分析。研究结果显示,色泽参数a^*和h^*值可以作为菠萝叶片指示色泽、主要色素含量和抗氧化活性变化的重要指标;菠萝叶片主要色素组成是叶绿素、类黄酮和总酚,且含有少量的花青苷,几乎不含类胡萝卜素。相关性分析结果显示,菠萝叶片类黄酮和总酚含量均与3种抗氧化活性指标极显著正相关,而叶绿素含量与其它指标相关性未达到显著水平,类黄酮和总酚是菠萝叶片抗氧化活性的主要功效成分。

Relationship among colors,pigments, and antioxidant activities of pineapple leaves

Twenty-two pineapple (Ananas comosus) cultivars were used to study the relationships among five color parameters (L^*, a^*, b^*, c^*, and h^* values), five pigment types (chlorophyll, carotenoids, anthocyanins, flavonoids, and total phenols), and three antioxidant activity indices (ABTS, DPPH, and nitrite assay) of leaves. The results indicated that color parameters a^* and h^* were important indicator indices for color, main pigment content, and antioxidant activity of pineapple leaves. The main pigment composition of the pineapple leaves was chlorophyll, flavonoids, and total phenols, with a small amount of anthocyanins and almost no carotenoids. Correlation analysis indicated that antioxidant activity was significantly positively correlated with flavonoid and total phenol content, but chlorophyll content was not significantly correlated with the other indicators. Flavonoids and total phenols were the main active compounds of antioxidant activity in pineapple leaves.