摘要:本研究分别采用水、乙醇、50%乙醇、丙酮和50%丙酮五种溶剂提取4种常见的蔬菜豆苗、紫椰菜、丝瓜及芹菜的抗氧化活性物质,然后运用DPPH法对提取的四种蔬菜的抗氧化物质进行抗氧化活性分析,从而判断四种蔬菜的抗氧化性及五种溶剂对四种蔬菜抗氧化物质提取能力的影响,结果显示:四种蔬菜都具有一定的抗氧化性,而且豆苗>芹菜>紫椰菜>丝瓜。不同提取方法对提取效果具有一定的影响,其中,水提取法对紫椰菜抗氧化物质提取效果最佳,50%乙醇提取丝瓜效果好,无水乙醇提取芹菜效果好,丙酮提取豆苗效果较好。所得结果不仅对我们日常生活中健康饮食的优化及食物的贮存、运输都有一定的指导意义,且对食品的工业加工处理也具有重要意义。57577
毕业论文关键词:豆苗,紫椰菜,丝瓜,芹菜,提取物,DPPH,抗氧化性
Abstract: Antioxidant components of vegetables, including bean seedling, purple cabbage, towel gourd and celery, were extracted with water, 50% ethanol, ethanol, 50% acetone and acetone. And in order to estimate the antioxidant ability of the vegetables, the antioxidant activity were assayed by using the DPPH• method. The results shows that all the four vegetables possessed certain antioxidant ability. And from high to low the sequences of DPPH• radicals-scavenging activity were bean seedling, celery, purple cabbage and towel gourd. Different extracting method had various influences on the extracting efficacy. For the purple cabbage, water extraction method appeared to be the best in extracting the antioxidant components. On the other hand, preferable results of extracting the antioxidant components from towel gourd, celery, bean seedling, were obtained with solvents of 50% ethanol, absolute ethanol and absolute acetone, respectively. This study not only provides guidance for a healthy diet of our daily life, food storage and transportation, but also can be applied to the food processing industry.
Keywords:bean seedling,purple cabbage,towel gourd,celery,extract ,DPPH ,antioxidative
目 录
1 前言 4
2 材料与方法 5
2.1 材料 5
2.2 试剂 6
2.3 仪器 6
2.4 实验方法 6
2.4.1 样品的预处理 6
2.4.2 DPPH溶液配制 6
2.4.3 提取液的制备 6
2.4.4 提取物溶液的配制 6
2.4.5 抗氧化性的测定 6
3 结果与分析 7
3.1 豆苗5种溶剂提取物的DPPH•清除率 7
3.2 紫椰菜5种溶剂提取物的DPPH活性 8
3.3 丝瓜5种溶剂提取物的DPPH活性 9
3.4 芹菜5种溶剂提取物的DPPH活性 9
3.5 同种溶剂提取剂中四种蔬菜的自由基清除率 10
3.6 四种果蔬对DPPH清除作用比较 11
结 论 12
参考文献 13
致 谢 14
1 前言
自由基是机体内氧化代谢反应中产生的有害基团,具有很强的氧化性,可损害机体的组织和细胞,进而机体的衰老效应及引起慢性疾病[1]。 然而,自由基也是机体正常代谢的产物,其不仅可以促进细胞代谢、增殖,而且也具有刺激白细胞和吞噬细胞,同时还具有杀灭细菌,消除炎症,分解机体内有毒产物等功能。尽管如此,但由于外界环境污染、食品添加剂、食物农药残留、烟草、酒精等外来因素引入机体,从而导致机体自由基过量,引发机体的新陈代谢紊乱等诸多不良反应。此外,更为严重的是,过多的自由基能够引起机体蛋白质、脂类及核酸等生命大分子过氧化损伤,甚至导致重大疾病[2]。