雪莲果体外抗氧化和自由基清除能力

抗氧化能力是衡量果蔬营养及保健价值的重要指标之一。雪莲果是一种药食两用植物,对多种慢性疾病有缓解作用。分别采用5 种方法(DPPH、ABTS、FRAP、SASR 和MCC)对雪莲果块根甲醇提取液的自由基清除能力及抗氧化活性进行体外评价。结果表明：DPPH 法测定的Trolox 当量抗氧化能力(TEAC)为410.263mg Trolox/g md,抗坏血酸当量抗氧化能力(AEAC)为230.485mg VC/g md,IC50 值为1.464mg/mL;ABTS 法测定的TEAC 为267.584mg Trolox/g md,AEAC为41.597mg VC/g md,IC50 值为1.269mg/mL;SRSA 法测定的TEAC 为652.816mg Trolox/g md,AEAC 为101.451mg VC/g md,IC50 值为7.720mg/mL。说明雪莲果块根提取物对DPPH 自由基、ABTS+·和O2·三种不同的自由基均有一定的清除活性。此外,雪莲果块根提取物还具有较高的总抗氧化(FRAP 值为131.723 mgFeSO4/g md)和较强的金属螯合能力(73.193%)。     

雪莲果叶中多酚的提取工艺研究

以雪莲果叶为原料,采用醇提方法提取其多酚物质。通过单因素、正交试验和方差分析确定了最佳提取条件为：乙醇浓度30%,料液比1:40,提取温度70℃,提取时间1h,提取2 次。在最佳条件下多酚的提取量为32.92mg/g,此结果可为雪莲果叶的开发利用提供技术依据。     

Effect of Yacon (Smallanthus sonchifolius) fructooligosaccharide purification technique using activated charcoal or ion exchange fixed bed column on recovery,purity and sugar content

A rich in FOS and simple sugar yacon extract was clarified and decoloured and subsequently purified in an activated charcoal column at 25 and 40 °C using two or three stepwise elution with yields of 72.0–86.7% and 90–92.4% purity. Best results were obtained at 25 °C and two stepwise elution, with yield and purity of 81.5% and 92% but 9% sucrose and no glucose and fructose. Different cationic exchange resins on a clarified and demineralised extract at 25 and 60 °C had yields and purity of 73.1–99.4% and 75.0–88.2%, respectively. Best results were obtained with Diaion UBK530Na at 60 °C (99.4% yield and 88.2% purity) but 1.6, 2.7 and 7.5% of fructose, glucose and sucrose. The by‐product was rich in sugars (59–60.1% fructose, 28.3–32.8% glucose, 7.2–8.4% sucrose) and could be used by the feed and food industry.