發(fā)布時間：2019-03-21 12:48

【摘要】：肌肽(Car,β-alanyl-L-histidine)和鵝肌肽(Ans,β-alanyl-L-1-methylhistidine)等組氨酸二肽廣泛存在于多脊椎動物的骨骼肌和代謝旺盛的腦中,具有多種生理活性和功能,可作為食品添加劑應(yīng)用于食品加工行業(yè)中,低值肉類尤其是下蛋母雞等是其廉價來源。介孔氧化硅材料具有高比表面積和大小可調(diào)的孔徑率在吸附和分離中具有巨大的應(yīng)用潛力。本論文旨在利用組氨酸二肽含有咪唑基的特性,設(shè)計合成金屬摻雜介孔材料,對其進行表征并研究其對組氨酸二肽的吸附特性,建立動力學(xué)和吸附等溫線模型研究機理。結(jié)果為金屬摻介孔材料在組氨酸二肽等功能肽分離純化領(lǐng)域的應(yīng)用提供了理論依據(jù)。首先,建立組氨酸二肽的HPLC檢測方法。采用OPA柱前衍生法快速測定提取液中肌肽和鵝肌肽含量。測定不同物種及同一物種不同部位中組氨酸二肽含量,發(fā)現(xiàn)蛋雞肉中含有較高的組氨酸二肽(21.58 pmol/g)。又由于蛋雞經(jīng)濟價值低廉,因此是提取組氨酸二肽的理想來源。采用切丁、絞碎、攪拌、超聲、蒸煮及酶解方法提取組氨酸二肽,絞碎后攪拌方法能夠最大化的提取二肽且引入其他氨基酸及多肽較少。采用1000 Da超濾膜和500 Da納濾膜兩步法進行分離,除大分子蛋白和肽,經(jīng)氨基酸分析,組氨酸二肽含量約60%。其次,采用兩步法合成金屬摻雜介孔材料。采用羧基化改性劑CES在SBA-15骨架中加入羧基,通過XRD、TEM、BET等進行表征,羧基化介孔材料S-COOH仍保持SBA-15中二維六方孔道結(jié)構(gòu),而隨CES添加量增加,孔道發(fā)生破壞、塌陷和粘連,有序性降低。經(jīng)改性后S-COOH具有Ⅳ型吸附曲線和H1型滯后環(huán),而改性后孔容、孔徑和比表面積均有下降。采用金屬硝酸鹽合成金屬摻雜介孔材料,以Ni/SBA-15為例,采用XRD、 BET、ICP等進行表征發(fā)現(xiàn),添加金屬的濃度需在一定范圍內(nèi)。第三,對合成材料吸附組氨酸二肽特性進行研究。探究改性介孔材料預(yù)處理條件、金屬種類、金屬添加量對組氨酸二肽吸附的影響,結(jié)果表明Ni50/SBA-15具有良好的吸附容量；研究pH和無機鹽對其吸附的影響,發(fā)現(xiàn)pH 6-7范圍內(nèi)具有較大的吸附容量(20℃C,當pH 7.0,添加量0.5 g/L時,吸附容量為0.69mmol/g),無機鹽對其吸附無較大影響。對Ni50/SBA-15吸附組氨酸二肽洗脫的研究中發(fā)現(xiàn),采用50mmol/L咪唑為最佳洗脫條件。最后,建立Ni50/SBA-15對組氨酸二肽吸附的動力學(xué)方程和吸附等溫線。分別采用偽一級、偽二級和顆粒內(nèi)擴散模型進行動力學(xué)擬合,發(fā)現(xiàn)其符合偽二級動力學(xué)方程(R2在0.983-0.999范圍內(nèi))。采用Langmuir模型和F reundlich模型對其進行擬合發(fā)現(xiàn),吸附過程符合Langmuir模型(R2在0.994-0.998范圍內(nèi)),吸附為單層吸附。由Freundlich模型得出,該吸附為可逆吸附。
[Abstract]:Histidine dipeptides, such as Car, 尾-alanyl-L-histidine and Ans, 尾-alanyl-L-1-methylhistidine, exist widely in skeletal muscle and metabolic brain of polyvertebrates, and have many physiological activities and functions. It can be used as a food additive in the food processing industry, low-value meat, especially laying hens are its cheap source. Mesoporous silica materials have great potential in adsorption and separation with high specific surface area and adjustable pore diameter. The purpose of this paper is to design and synthesize metal-doped mesoporous materials based on the properties of histidine dipeptide containing imidazolyl groups and to study the adsorption characteristics of histidine dipeptides and to establish a kinetic and adsorption isotherm model for studying the mechanism of the metal-doped mesoporous materials. The results provide a theoretical basis for the application of metal-doped mesoporous materials in the separation and purification of functional peptides such as histidine dipeptides. Firstly, a HPLC method for the detection of histidine dipeptide was established. The contents of carnosine and goose carnosine in the extract were determined by OPA pre-column derivatization. The content of histidine dipeptide in different species and different parts of the same species was determined. It was found that there was a higher histidine dipeptide (21.58 pmol/g) in egg chicken. Because the economic value of laying hens is low, it is an ideal source for extracting histidine dipeptide. Histidine dipeptides were extracted by cutting, chopping, stirring, ultrasonic, cooking and enzymolysis methods. The dipeptides were extracted maximally by agitation method and the addition of other amino acids and polypeptides was less than that of other amino acids and peptides. 1000 Da ultrafiltration membrane and 500 Da nanofiltration membrane were used for separation. The content of histidine dipeptide was about 60% after amino acid analysis. Secondly, metal-doped mesoporous materials were synthesized by two-step method. Carboxylation modifier CES was used to add carboxyl groups to SBA-15 framework and characterized by XRD,TEM,BET et al. The carboxylation mesoporous material S-COOH still maintained the two-dimensional hexagonal pore structure in SBA-15. However, with the increase of CES content, the pore channel was destroyed. Collapse and adhesion, order decreased. The modified S-COOH exhibited type 鈪，

本文編號：2444945