Abstract

The impact of solvent polarity on the kinetics, reducing capacity, antioxidant activity, and mineral composition of black locust (Robinia pseudoacacia) flowers extracts obtained by ultrasound-assisted extraction was investigated. The DPPH assay and the Folin-Ciocalteu method were applied to define the antioxidant activity and reducing capacity of the extracts, respectively. The mineral content was defined using the ICP-OES method. Ponomaryov and non-stationary diffusion models were used for modeling the extraction of antioxidants. The obtained results showed that antioxidant activity, phenolic and mineral contents of the extracts were varied significantly depending on the solvent polarity. The highest reducing capacity (3.78 g gallic acid equivalent per 100 g dry weight) had the 50% (v/v) methanol extract, while the strongest antioxidant activity (IC₅₀ = 0.3381 mg/mL) was found in the 50% (v/v) ethanol extract. HPLC analysis showed that water as a solvent had the highest extraction capacity for vanillic acid and catechin hydrate. ICP-OES analysis confirmed that the black locust flower extracts are rich in macroelements (Ca, Na, Mg, K) with low content of heavy metals (Pb, Cd). The 50% (v/v) ethanol extract had the highest amount of macroelements, predominantly potassium (10.49 g/kg). The prepared extracts due to good antioxidant activity, high phenolic and mineral content, and low heavy metal contents can be considered useful for further human uses.

摘要

溶剂极性对刺槐（刺槐）动力学、还原能力、抗氧化活性和矿物质组成的影响) 研究了通过超声辅助提取获得的花提取物。DPPH 测定法和 Folin-Ciocalteu 法分别用于确定提取物的抗氧化活性和还原能力。使用 ICP-OES 方法确定矿物质含量。Ponomaryov 和非平稳扩散模型用于模拟抗氧化剂的提取。所得结果表明，提取物的抗氧化活性、酚类和矿物质含量随溶剂极性的不同而显着变化。50% (v/v) 甲醇提取物的还原能力最高（每 100 g 干重 3.78 g 没食子酸当量），而抗氧化活性最强（IC ₅₀= 0.3381 mg/mL) 在 50% (v/v) 乙醇提取物中发现。HPLC分析表明，作为溶剂的水对香草酸和儿茶素水合物的萃取能力最高。ICP-OES分析证实刺槐花提取物富含大量元素（Ca、Na、Mg、K），而重金属（Pb、Cd）含量较低。50% (v/v) 乙醇提取物的微量元素含量最高，主要是钾 (10.49 g/kg)。由于良好的抗氧化活性、高酚和矿物质含量以及低重金属含量，制备的提取物可被认为可用于进一步的人类用途。