【作者】 罗季阳；

【导师】 田呈瑞；

【作者基本信息】 陕西师范大学 ， 食品科学， 2004， 硕士

【摘要】 杜仲（Eucommia ulmoides Oliv）是杜仲科杜仲属植物，是我国传统的珍贵药材，具有补肝肾、强筋骨、降血压、抗衰老、抗肿瘤等功效。杜仲叶与杜仲皮在功效上相当，只是在某些成分含量上有差异，具有良好的开发前景，可以作为杜仲皮的替代品。 杜仲叶活性成分提取，主要有水提取法和有机溶剂提取法，这两种方法都有一定的缺点。本文采用纤维素酶和果胶酶对杜仲叶活性成分进行提取，取得了良好的效果。 自由基生物学研究认为，导致癌症、衰老、肿瘤、免疫力下降等疾病的原因之一是体内自由基堆积过多，超出自身清除自由基的能力，引起生物膜上脂类过氧化，导致膜结构损伤和功能破坏，细胞活力下降，因此，必须引入外源性的自由基清除剂，以维持体内自由基的平衡。本文通过用三种不同抗氧化体系对杜仲叶酶提取物、乙醇提取物进行了体外抗氧化效果的评价，并对其反应动力学进行了研究。 本试验还对不同加工条件及方法对酶提取杜仲叶活性成分的影响进行了研究，通过明胶澄清、β-环状糊精对活性成分进行包埋，提高了酶提取杜仲叶活性成分的加工适应性。另外，通过对加热温度、pH、加热时间等因素的研究，以期为杜仲叶功能食品的加工提供依据。 主要试验结果如下： 1．纤维素酶是提取杜仲叶活性成分的一种有效酶类，但果胶酶以及果胶酶和纤维素酶的联合作用的提取效果均较差。 2．纤维素酶提取杜仲叶活性成分的最佳工艺参数为pH4.5、加酶量0.01％、提取温度55℃、提取时间2.5h。 3．清除DPPH自由基体系中，在0.16～10.00mg／ml的浓度范围内，杜仲叶酶提取物和乙醇提取物清除DPPH自由基的能力分别是：47.62～78.15％和5.12～81.99％，当浓度分别达到0.62mg／ml和2.5mg／ml时，清除率基本达到最大值，而作为对照的TBHQ在0.02～1.25mg／ml的浓度剂量范围内表现为：32.83～85.09％的清除率，当TBHQ的浓度达到0.16mg／ml时，清除率基本达到最大值。 4．Fe²⁺螯合能力试验中，杜仲叶酶提取物和乙醇提取物在0.62～20mg／ml的浓度剂量范围内，其Fe²⁺螯合率分别为25.06～75.76％和0.54～33.43％，当浓度剂量达到5.00mg／ml时，杜仲叶酶提取物Fe²⁺螯合率基本达到最大值，而在试验的浓度范围内，TBHQ未检测到有Fez+鳌合能力。 5.亚油酸氧化体系中，在0.31一10.00mg/m1的浓度剂最内，杜仲叶酶提取物对烷基自由基的清除率最高只达到39.05%，而杜仲叶乙醉提取物为34.42%，而在0.04一1.25lug/m1的浓度剂量内，TBHQ的最高清除率则达到86.99%， 6.除TBHQ在Fe2+鳌和试验中未检测到外，在三种抗氧化反应体系中，三种抗氧化物质的浓度剂量在一定范围内与抗氧化效果呈良好的指数曲线关系，郎抗氧化效果在一定范围内随抗氧化剂的浓度剂量的增加而显著增加，但当达到一定的抗氧化效果时，随着浓度剂量的进一步增加，抗氧化效果的增量不大或不明显. 7.从瓜。值和K值可以看出，TBHQ是三种抗氧化剂中清除DPPH自由签效果最好的抗氧化剂，其次为杜仲叶酶提取物，最后为杜仲叶乙醉提取物。杜仲叶酶提取物表现出良好的Fez+鳌和能力，杜仲叶乙醇提取物在试验中的浓度剂童范围内未达到50%的Fe卜鳌和率，而TBHQ在试验中的浓度荆量范围内未发现有Fe跳的鳌和能力。杜仲叶酶提取物和乙醇提取物在亚油酸氧化体系试验中的浓度剂蚤范围内抑制率均未达到50%，而TBHQ的效果最好。 8.明胶加量为0.巧%时，杜仲叶酶提取液的澄清效果最好。 9.p一环状糊精添加量为1.2%时，杜仲叶酶提取液中活性成分热稳定性嘴显增强，苦涩味等不良口味明显减轻。 10.pH值4.0⁵.0时，杜仲叶酶提取液中活性成分热稳定性较好，另外在加工中应尽量避免70℃以上高温长时间处理。 11.蔗糖和Vc对杜仲叶酶提取液中活性成分热稳定性都有一定的影响，当蔗糖浓度为6%、Vc为0.06%Vc时，其稳定性最好。更多还原

【Abstract】 Abstracts: Eucommia ulmoides Oliv is a precious herb in China, it has many kinds of function compositions. Eucommia ulmoides Oliv leaves and Eucommia ulmoides Oliv bark are about equal on the functions, just there are diffiences on the content of some.In the paper, the cellulose and pectinase technology of extracting function compositions from Eucommia ulmoides Oliv leaves have been studied. This study evaluated antioxidative activities of enzyme extract and ethanolic extract from Eucommia ulmoides Oliv leaves in three kinds of antioxidative systems, and processing properties of enzyme extract from Eucommia ulmoides Oliv leaves was also investigated.The main results are listed as follows:1. Cellulose is a effective enzyme in extracting function compositions from Eucommia ulmoides Oliv leaves, but pectinase and union of cellulose and pectinase are relatively bad.2. The optimum parameters for cellulose extracting function compositions from Eucommia ulmoides Oliv leaves:pH4.5, extracting time of 2.5h, adding amount of enzyme of 0.01 %, extracting temperature of 55 ℃.3. In DPPH system, at a dosage of 0.16~ 10.00mg/ml,enzyme extract and ethanol extract from Eucommia ulmoides Oliv leaves showed 47.62~78.15% and 5.12~81.99% scavenging activity of DPPH radical, compared with TBHQ showed 32.83-85.09% at a dosage of 0.02-1.25mg/ml.4. In Fe2+-chelating ability system, at a dosage of 0.62-20.00mg/ml,enzyme extract and ethanol extract from Eucommia ulmoides Oliv leaves showed 25.06-75.76% and 0.54-33.43%,but,TBHQ can not be detected Fe2+-chelating effect at dosage of 0.02-1.25mg/ml.5. In linoleic acid system, at a dosage of 0.31 -10.00mg/ml.the enzyme extract from Eucommia ulmoides Oliv leaves showed 39.05% highest scavenging activity ,the ethanol extract showed 34.42%,compared with TBHQ showed 86.99% at a dosage of 0.04-1.25mg/ml.6. The relation between concentration of three kinds of antioxidant andantioxidative results display good index curve within contain range. In other words, the antioxidative activity increased with antioxidant concentration to a certain extent, then leveled off with further increase in antioxidant concentrations.7.On the basis of IC50 and K- results, TBHQ was found to be the most effective DPPH radical-scavenger, followed by the enzyme extract and the ethanol extract. The enzyme extract demonstrates good in Fe2+-chelating capability, the ethanol extract has not reached 50% and TBHQ did not exhibit a detectable Fe2+-chelating capability. In linoleic acid system ,the enzyme extract and the ethanol extract have not reached 50% ,TBHQ demonstrates good in scavenging activity.8.The clarification result is best in extracting the liquid from Eucommia ulmoides Oliv leaves at adding amount of gelatin of 0.15%.9. At adding amount of 3 -cyclodextrin of 1.2%,the hot stability of the function compositions is obviously strengthened, pained flavor obviously lightens.10.Should try one’s best to prevent more than 70C of high temperature from being dealt with for a long time in processing.11.Cane sugar and Vc have certain influences for hot stability of function compositions, consider synthetically, choose cane sagar of 6% , Vc of 0.06%.更多还原