摘 要本实验研究了采用超声波辅助处理，碱性蛋白酶酶解麦谷蛋白制备抗氧化肽的工艺条件及所得抗氧化肽的抗氧化活性。以对DPPH自由基的清除率作为抗氧化性指标，使用超声波作为辅助手段，考察了超声功率、超声时间、底物浓度、加酶量、酶解温度、酶解时间及pH对麦谷蛋白抗氧化肽制备的影响。经正交试验和验证实验，得出超声辅助制备麦谷蛋白抗氧化肽的最佳工艺参数为：超声功率300 W、超声时间10 min、底物浓度60 mg/mL、加酶量3000 U/g、酶解温度45 ℃、酶解时间20 min、pH 7。0。在此工艺条件下制备的抗氧化肽DPPH自由基清除率高达92。51 %。

以相同浓度的维生素C作为对照，考察最佳工艺条件下制备的麦谷蛋白抗氧化肽的抗氧化活性。结果表明：抗氧化肽总还原力远不如同浓度的VC；与Fe2+螯合能力显著；0。5 mg/mL抗氧化肽溶液的DPPH自由基清除率接近同浓度下的VC。86843

毕业论文关键词: 麦谷蛋白；超声；抗氧化肽；DPPH自由基清除率

Abstract  Ultrasound-assisted preparation of antioxidant peptides from gluten were studied。 We took the DPPH scavenging ratio as an indicator of antioxidant and used ultrasound as auxiliary means to study the effects of ultrasonic power, ultrasonic time, substrate concentration, enzyme dosage, enzyme hydrolysis temperature, hydrolysis time and pH on preparation of antioxidant peptides from gluten。 The results showed that the optimum conditions by single-factor experiment and orthogonal experiment were 300 W of ultrasonic power, 20 min of ultrasonic time, 60 mg/mL of substrate concentration, 3000 U/g of the amount of enzyme, 45 ℃ of enzyme hydrolysis temperature, enzymolysis time 20 min, and pH 7。0。 DPPH scavenging ratio prepared under this condition was as high as 92。51%。

With the same concentration of Vc as control group, the antioxidant activity of antioxidant peptides from gluten under the conditions of the optimum process were investigated。 The results showed that the total reduction capacity was lower than that of Vc solution with the same concentration。 DPPH scavenging ratio at the concentration of 0。5 mg/mL was close to that of Vc at the same concentration。

Keywords: Glutenin; Ultrasonic-assisted; Antioxidant peptide; DPPH scavenging ratio

目 录

第一章 绪 论 1

1。1 本实验的研究意义 1

1。2 麦谷蛋白 1

1。2。1谷朊粉 1

1。2。2 麦谷蛋白性质和结构 2

1。2。3麦谷蛋白的应用 3

1。3 抗氧化肽 3

1。3。1 生物活性肽 3

1。3。2 抗氧化活性肽 3

1。3。3 抗氧化肽的制备 4

1。3。4 抗氧化肽的测定方法 5

1。3。5 发展趋势 6

1。4 超声波 6

1。5 研究目的和研究内容 7

1。5。1 研究目的 7

1。5。2 研究内容 7

第二章 实验材料与方法 8

2。1 实验仪器和试剂 8

2。1。1 实验药品 8

2。1。2 实验仪器 8

2。2 实验方法 8

2。2。1 测定蛋白质含量