牛骨髓蛋白及其碱性蛋白酶酶解物的功能特性比较

Comparison of the Functional Characteristics of Bovine Bone Marrow Protein and Its Hydrolysate Obtained with Alkaline Protease

该研究通过水提法提取牛骨髓蛋白(Bovine Bone Marrow Protein,BBMP),采用碱性蛋白酶制备牛骨髓蛋白酶解物(Bovine Bone Marrow Alkaline Protease Hydrolysate,BBMP-AH),测定两者的氨基酸含量,同时比较分析结构特征、理化性质以及抗氧化活性。结果表明,BBMP-AH蛋白含量高于BBMP,BBMP-AH必需氨基酸和疏水性氨基酸含量明显的增加;紫外和红外光谱图谱表明,BBMP及BBMP-AH均显出典型的蛋白吸收峰且酶解后蛋白质二级结构发生了明显的变化;理化性质试验结果表明,BBMP及BBMP-AH的等电点在pH值6左右,远离等电点时,具有较好的理化特性,酸碱性条件下理化性质显著改善。与原蛋白相比,酶解物最高溶解性提高到94.40%、乳化性为1.24 m^(2)/g、乳液稳定性为116.33%,持水性为3.94 g/g,持油性略有降低;BBMP-AH的抗氧化活性显著强于BBMP,均具有较强的DPPH•、•OH、O_(2)^(-)•、ABTS^(+)•清除能力和总还原能力。综上,酶解处理能够改善牛骨髓蛋白理化性质,提高其抗氧化能力,延伸开发应用范围。

In this study,bovine bone marrow protein(BBMP)was extracted by the water extraction method,and alkaline protease was used to prepare BBMP hydrolysate(Bovine bone marrow protein alkaline protease hydrolysate,BBMP-AH).The amino acid contents of both BBMP and BBMP-AH were determined,and the structural characteristics,physicochemical properties,and antioxidant activities were compared and analyzed.The results showed that the protein content of BBMP-AH was higher than that of BBMP,and BBMP-AH contained higher contents of essential amino acids and hydrophobic amino acids.The UV and FT-IR spectra showed that both BBMP and BBMP-AH exhibited typical protein absorption peaks,and the protein’s secondary structure underwent significant changes after enzymatic hydrolysis.The examinations of physicochemical properties revealed that the isoelectric points of BBMP and BBMP-AH were around pH 6.When the pH was far from the isoelectric point,BBMP and BBMP-AH exhibited better physicochemical properties,whilst the physicochemical properties were significantly improved under acidic and alkaline conditions.Compared with the original protein,the highest solubility of the enzymatic hydrolysate increased to 94.40%,the emulsifying ability was 1.24 m^(2)/g,the emulsion stability was 116.33%,and the water-holding capacity was 3.94 g/g,with a slight decrease in oil-holding capacity.The antioxidant activity of BBMP-AH was significantly stronger than that of BBMP,with both BBMP-AH and BBMP having relatively strong DPPH·,·OH,O_(2)^(-)·,and ABTS^(+)·scavenging abilities and total reducing capacity.In summary,the enzymatic hydrolysis treatment could significantly improve the physicochemical properties of bovine bone marrow protein,increase its antioxidant capacity,and expand the development and application scope of bovine bone marrow protein.