米糠提取物超声辅助提取工艺及抗氧化活性

以乙醇为提取溶剂，采用响应面法对米糠提取物的超声辅助最佳提取工艺进行探讨。米糠提取物的总酚含量及抗氧化活性分别采用Folin-Ciocalteu 法和 Trolox 等价抗氧化能力(TEAC)方法测定。结果表明：总抗氧化活性随着总酚含量的增加而增大，但其活性高低并不完全取决于总酚物质。米糠提取物最佳提取工艺条件为乙醇体积分数90%(V/V)，提取温度55℃，提取时间97min。在此条件下，米糠提取物的总酚含量为(2.76 ± 0.17)mg GAE/g米糠(n=3)，总抗氧化活性为(2.99 ± 0.24)μmol TEAC/g 米糠(n=3)。

Response Surface Methodology for Optimizing the Ultrasonic-assisted Extraction of Rice Bran Extract with Both High Total Phenolic Content and Total Antioxidant Capacity

Response surface methodology was employed to optimize the process conditions for the ultrasonic-assisted extraction of rice bran extract with ethanol as the extraction solvent for achieving both high total phenolic content (TPC) and total antioxidant capacity (TAC). The determinations of TPC and TAC were performed using Folin-Ciocalteu method and trolox equivalent antioxidant capacity (TEAC) assay, respectively. The rice bran extract with higher showed higher TPC showed higher TAC. However, there was no absolutely dependent relationship between the two parameters. The optimal conditions for extracting rice bran extract with both high TPC and TAC were determined as follows: ethanol concentration, 90%; extraction temperature 55 ℃; and extraction duration 97 min. Under these conditions, a TPC of (2.76 ± 0.17) mg GAE/g bran (n = 3) and a TAC of (2.99 ± 0.24)μmol TEAC/g bran (n = 3) were observed.