蚕蛹蛋白论文：蚕蛹抗氧化多肽的制备及分离纯化研究
【中文摘要】人类许多慢性疾病及衰老现象均和人体内的自由基水平失衡有关,外源性抗氧化剂可以帮助人们维持体内自由基的平衡。通过对具有抗氧化活性的天然食物进行研究、筛选和改性有可能开发出有效的抗氧化药物和保健食品蚕蛹蛋白是一种优质蛋白质资源,含有18种氨基酸,其中8种人体必需氨基酸含量超过氨基酸总量40%,其蛋白含量约为50%,是一种比大豆蛋白更具营养价值的优质蛋白质资源本论文研究了蚕蛹蛋白粉的提取,酶解工艺条件,多肽抗氧化活性的检测方法,以及蚕蛹多肽中具有DPPH·清除活性的多肽的分离纯化。1.蚕蛹蛋白粉的脱脂及前处理。选取常规溶剂正己烷,丙酮,乙酸乙酯,无水乙醇分别作为单一脱脂溶剂做脱脂优化,以脱脂率为指标,得到最佳脱脂溶剂为丙酮。以超声细胞破碎法,微波破碎法,去离子水浸泡法三种方法对蛋白粉进行破碎处理,以上清液中蛋白含量为指标,得到最佳的破碎处理条件为超声波100HZ,间隔2sec,破碎10min2.建立了蚕蛹多肽体外抗氧化活性的检测方法。检测了蚕蛹蛋白水解液的抗氧化能力,包括清除超氧阴离子、清除羟自由基、清除DPPH·、
【英文摘要】Many chronic diseases and human aging phenomenon have something to do with the imbalance of free radicals inside human body. External antioxidants can help people to maintain the balance of free radicals inside body.
It’s possible to develop effective antioxidant drugs and health foods on the base of the research, screening and modification of natural foods with antioxidant activity. Silkworm pupa is a high quality protein resources, containing 18 amino acids, including 8 essential amino acids, the content of which is more than 40%。The protein content of pupa is about 50%.It is more nutritional than soybean protein whit high quality protein resources.In this paper, the detection methods of antioxidant activity of silkworm pupa protein peptides, the enzymatic hydrolysis conditions of silkworm pupa protein, and the purification of peptides with DPPH radicals scavenging activity of silkworm pupa protein peptides were investigated.1. Degrease of silkworm protein powder and pretreatment: Selecing the conventional solvent n-hexane, acetone, ethyl acetate, and ethanol as a single degreasing solvent to get a optimized degreasing rate, the best degreasing solvent aceton is acetone. The protein powder was crushing by three metod of ultrasound crushing, microwave crushing and soaking deionized water. With the crushing of protein content in the supernatant as an index, the best conditions for ultrasonic crushing is 100HZ, interval 2sec, 10min.2. Detection methods of vitro antioxidant activity of silkworm pupa protein powder peptides were established.
Antioxidant capacity of silkworm protein powder fowl protein were detected, including scavenging activity of super oxide anion, hydroxyl radicals, and DPPH free radicals, reductive ability and ability to prevent lipid peroxidation. Experimental results showed that silkworm protein powder peptides showed some antioxidant activity in different detection systems. Scavenging activity of DPPH free radicals was the highest. It showed good prospects in development.3. Further enzymatic hydrolysis technics of silkworm pupa protein was determined. After single enzyme hydrolysis experiment as DPPH free radicals scavenging for target, the best enzyme was pepsin. After L16(45) orthogonal test, the optimum conditions of pepsin digestion were temperature 50℃, initial pH1.5, 8000U/g of E/S, 6h of enzymatic hydrolysis time, 4% of substrate concentration.4. Antioxidant peptides were purified as hydroxyl radical scavenging ability for target. The best Sephadex G-25 gel chromatography separation conditions of silkworm pupa protein peptides were determined: eluted with deionized water, 0.2mL/min elution speed, 10mg/mL of sample concentration, and 0.50mL sample. Silkworm pupa protein peptides could be separated into three peaks, among which the three peak had the highest hydroxyl radical scavenging activity.