《紫苏叶抗氧化物的提取分离及其在油脂中抗氧化应用研究》由会员分享,可在线阅读,更多相关《紫苏叶抗氧化物的提取分离及其在油脂中抗氧化应用研究(68页珍藏版)》请在金锄头文库上搜索。
1、福建农林大学 硕士学位论文 紫苏叶抗氧化物的提取分离及其在油脂中抗氧化应用研究 姓名:朱元龙 申请学位级别:硕士 专业:农产品加工及贮藏工程 指导教师:陈绍军 20100401 I 摘 要 紫苏(Perilla frutescens(L.)Britt)为唇形科紫苏属药用植物,是我国传统的多 用途经济作物,也是国家卫生部公布的首批药食同源 60 个品种之一。紫苏叶、茎 及果实中含有丰富的黄酮类和萜类物质,具有抗氧化、抗衰老、抑菌、预防和抑制 肿瘤、降血糖、抗过敏等功效。为了更好地开发利用中草药紫苏资源,本文以紫苏 叶为原料,采用超声波提取方法和超滤膜过滤方法结合试验设计优化紫苏叶抗氧化 物的提取
2、工艺和分离工艺,并研究抗氧化提取物在食用油脂中的抗氧化效果。主要 结果如下: 1、以 DPPH清除率为抗氧化活性评价指标,采用 L9(34)正交试验设计优化 紫苏叶抗氧化物超声波提取工艺条件,并比较超声波提取法和传统乙醇浸提法对 DPPH的清除效果。结果表明:超声波提取的最佳工艺条件为提取溶剂 75 %乙醇、 料液比 1:25 g/mL、超声温度 50 、超声功率 270 W、超声频率 45 KHz、超声处 理时间 15 min、超声提取次数 1 次。在此工艺条件下提取物对 DPPH的清除率达 94.58 %,比传统乙醇浸提法提高 6.69%。紫外可见光谱扫描表明超声波提取法和传 统乙醇浸提法
3、所得的产品物质成分基本一致。 2、在单因素预试验基础上,采用响应面 Box-Behnken 模型设计法研究超滤压 力、超滤温度、料液比等因素对紫苏叶粗提物分离效果的影响,并探讨其抗氧化提 取物的稳定性。结果表明:超滤的最佳工艺条件为:截留分子量 10000 D、超滤压 力 0.35 MPa、超滤温度 35 、液料比 1:1.8,在此条件下超滤分离的膜通量可达 24.24 L/m2h。紫外可见光谱扫描表明,超滤膜分离过程除去了大量的叶绿素 a 等杂 质。分离得到的抗氧化提取物在碱性环境下抗氧化活性基本丧失,酸性环境下抗氧 化活性较高,在 pH=6 左右抗氧化活性最为稳定,保存 25 d 对 DP
4、PH的清除率仍保 持 85 %左右,而温度和光照对紫苏叶抗氧化提取物的活性没有明显影响,。 3、采用烘箱强化贮藏法研究紫苏叶抗氧化提取物在大豆油和花生油中的抗氧 化作用,并比较柠檬酸、甘氨酸和维生素 C 与提取物复配后的抗氧化效果。结果表 明:紫苏叶抗氧化提取物对大豆油和花生油都有明显的抗氧化作用,提取物对花生 油的抗氧化能力(PF=2.14)优于大豆油(PF=2.03) 。0.2 %添加量的提取物对大豆 油的抗氧化作用强于 BHT, 与维生素 E 相当, 而对花生油的抗氧化作用均强于 BHT 和维生素 E。添加柠檬酸的复合抗氧化剂对大豆油和花生油的抗氧化作用均有大幅 II 提高,20 下大豆
5、油的预期货架寿命由 2.14 个月延长至 6.42 个月,花生油的预期 货架寿命由 3.07 个月延长至 7.73 个月。 关键词:紫苏叶 抗氧化 超声波提取 超滤 响应面 油脂抗氧化 III Abstract Perilla is a traditionally medicinal and edible plants in China. It belongs to medicinal plant of Labiatae Perilla, meanwhile it is one of the first batch of the 60 homology of medicine and food
6、 species that Ministry of Health has announced. The leaves, stems and fruits of perilla are rich in flavonoids and terpenoid and have the functions of antioxidant, anti-aging, antibacterial, prevention and suppression of tumor, hypoglycemic and anti-allergy. To better develop of resources of perilla
7、, taking perilla leaves as raw material in my research, using ultrasonic extraction and ultrafiltration methods combining with experimental designed to optimize the extraction and separation processes of perilla leaf antioxidant, and to study the antioxidant effects of the perilla leaf antioxidant i
8、n edible oil. The main results are as follow: Taking the clearance rate of DPPH as the antioxidant activity evaluation, the L9(34) orthogonal was adopted in the experimental design to optimize the ultrasonic extraction conditions of perilla leaf antioxidant, and compared the effect on DPPH of the ul
9、trasonic extraction to traditional ethanol extraction scavenging. The results indicated that the optimum ultrasonic extraction conditions are the ethanol extraction solvent is 75 %, the solid-liquid ratio is 1:25 g/mL, the ultrasonic temperature is 50 , the ultrasonic power is 270 W, the ultrasound
10、frequency is 45 KHz, the ultrasonic time is 15 min and the ultrasonic extraction times is once. Under these conditions, the extraction clearance rate of DPPH is 94.58 %. Compared to the traditional ethanol extraction the clearance rate increased 6.69 %. And the UV-Vis scans shows that composition of
11、 the product derived by ultrasonic extraction or traditional ethanol extraction were basically consistent. Basing on the single-factor trial test, Box-Behnken model of response surface analysis was used to indicate the effect of UF pressure, UF temperature and stock ratio on the separation of perill
12、a leafs crude extracts, and discussed the stability of the antioxidant extract. The results indicated that the optimum conditions for UF as follows: the MWCO is 10000 D, the UP pressure is 0.35 MPa, the UP temperature is 35 , the stock ratio is 1:1.8, the UF membrane flux under these conditions is 2
13、4.24 L/m2h. And the UV-Vis scans shows that UF filter most of chlorophyll-a which is impurity. There is IV not obvious influence of temperature and light on the antioxidant activity of perilla leaf extraction. The activity of perilla leaf extraction basically inactivated beyond the alkaline conditio
14、ns but higher under acidic conditions, and around pH6 the antioxidant activity is quite stable, after storing 25 d the clearance rate of perilla leaf extraction on DPPH remained around 85 %. Oven storage strengthen method was applied to research the anti-oxidation effect of the antioxidant (produced
15、 from perilla leaf) extract on the soybean oil and peanut oil. And the experiment also studied the effects of antioxidant the citric acid, glycine and VC compounded with the perilla leaf extract. The results indicated that the perilla leaf extract has a certain antioxidant effect on the soybean oil
16、and peanut oil, and the antioxidant ability of the extract on peanut oil (PF = 2.14) is stronger than that of soybean oil (PF = 2.03). The extracts antioxidant effect that add 0.2 % to soybean oil was stronger than that of BHT and the same to that of VE, while that add to peanut oil was stronger than the antioxidant BHT and VE. The complex antioxidant added citric acid of the soybean oil and peanut oil are a substantial increase in anti-oxidation, under 20 the shelf life of