超高压提取蓝莓渣花色苷的工艺优化及其抗氧化活性

本文旨在优化蓝莓渣花色苷的超高压提取工艺并考察其抗氧化活力。本文以蓝莓渣为原料，采用单因素实验和Box-Behnken响应面分析法对蓝莓渣花色苷的提取工艺进行优化，以维生素C（V_C）为阳性对照，通过DPPH自由基清除率、羟基自由基清除率和FRAP铁离子还原能力的测定，评估蓝莓渣花色苷的体外抗氧化活性，并采用高效液相色谱法（HPLC）对蓝莓渣花色苷组分进行分析。结果表明:蓝莓渣花色苷的最佳提取工艺条件为:提取压力400 MPa，提取时间9 min，乙醇浓度60%，料液比1:20 g/mL，此条件下花色苷的提取量为5.93±0.06 mg/g，与传统溶剂浸提法（CSE）、超声波辅助提取法（USE）相比，超高压辅助提取（UPE）法的提取效果更好，花色苷提取量分别提高25.11%、10.02%；蓝莓渣花色苷对DPPH?清除能力最强，与同浓度的V_C相比，无显著性差异（P>0.05）；其对?OH的清除率以及FRAP铁离子还原能力则显著弱于同浓度V_C（P<0.05）；HPLC分析结果表明，蓝莓渣花色苷包含13种花色苷单体，其中锦葵色素-3-半乳糖苷含量最高。因此，超高压辅助提取是一种高效的蓝莓渣花色苷提取方法，且蓝莓渣花色苷因其较强的抗氧化活性具有较好的应用价值。

Optimization of Ultra-high Pressure Extraction and the Antioxidant Activity of Anthocyanins from Blueberry Pomace

The objective of this study was to optimize the ultra-high pressure extraction (UPE) process of anthocyanins extracted from blueberry pomace and to investigate the antioxidant activity of the anthocyanin extracts. In the present study, the extraction process of anthocyanins was optimized by single factor experiments and Box-Behnken response surface methodology, using blueberry pomace as raw extraction material. The DPPH free radical scavenging rate, hydroxyl radical scavenging rate, and FRAP iron ion reducing ability of the extracts were determined to evaluate the in vitro antioxidant activity of blueberry pomace anthocyanins, with vitamin C (V_C) used as a positive control. The components of anthocyanins extracted from blueberry pomace were analyzed by high performance liquid chromatography (HPLC). The optimum conditions of the anthocyanins extraction from blueberry pomac were as follows: extraction pressure at 400 MPa, extraction time for 9 min, 60% ethanol concentration, solid-liquidratio at 1:20 g/mL. Under these conditions, the extraction yield of blueberry pomace anthocyanins was 5.93±0.06 mg/g. Compared to conventional solvent extraction (CSE) and ultrasonic-assisted extraction (USE), ultra-high pressure-assisted extraction (UPE) had the better extraction effect, with the extraction yield of blueberry pomace anthocyanins increased 25.11% and 10.02%, respectively. Blueberry pomace anthocyanins had strong DPPH free radical scavenging effect, which was comparable to the same concentration of V_C (P>0.05). However, the hydroxyl radical scavenging activity and the FRAP iron ion reducing ability of blueberry pomace anthocyanins were significantly lower than those of V_C at the same concentration (P<0.05). The 13 peaks of the anthocyanin extracts from blueberry pomace were tentatively identied by HPLC analysis, among which the content of malvidin-3-galactoside was the highest. These results indicated that UPE was an efficient method for extracting blueberry pomace anthocyanins which have potential application value to be used as a functional food ingredient or nutraceutical due to their antioxidant activity.