紫外诱导的光氧化对浓缩乳蛋白理化性质的影响
详细信息 查看官网全文
- 英文论文题名：Effects of UV induced photo-oxidation on the physicochemical properties of milk protein concentrate
- 论文作者：魏冠棉 ; 周鹏
- 英文论文作者：Guanmian Wei ; Peng Zhou ; State Key Laboratory of Food Science and Technology ; School of Food Science and Technology ; Jiangnan University
- 年：2016
- 作者机构：江南大学食品科学与技术国家重点实验室;
- 论文关键词：浓缩乳蛋白 ; 光氧化 ; 蛋白改性 ; 溶解性 ; LC-MS
- 英文论文关键词：Milk protein concentrate ; Photo-oxidation ; Protein modification ; Solubility ; LC-MS
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十三分会：质谱分析
- 语种：中文
- 分类号：O629.73
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十三分会 ; 质谱分析
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：222k
- 原文格式：D
- 会议级别：全国
摘要
本研究的目的是研究紫外诱导的光氧化对蛋白改性和浓缩乳蛋白(MPC70)的色泽与溶解性的影响。MPC70分别在25℃和40℃温度下进行储藏,相对湿度(RH)为11%、33%和75%。本研究采用液相色谱-质谱(LC-MS)研究溶解蛋白的变化,采用凝胶电泳研究不溶蛋白的变化。研究结果表明光氧化诱导L~%值显著降低;光氧化MPC70的溶解性显著降低,而未经紫外处理的MPC70样品溶解度维持不变,40℃和75%RH储藏的MPC70除外。与对照组相比,光氧化MPC70可溶部分的质谱图除了非糖基化和糖基化完整蛋白外,还显示出了多级附加片段,这表明光氧化诱导蛋白进一步的改性,这与蛋白中羰基基团的形成一致。在低相对湿度时,光氧化促进β-乳球蛋白的糖基化。光氧化MPC70的不同部分主要为酪蛋白和高分子聚集体,这主要是由光氧化诱导的非二硫化物交联引起。研究结果表明光氧化可以诱导蛋白改性,这最终引起了MPC70溶解度降低和变色。
The objective of this study was to investigate the effects of UV induced photo-oxidation on protein modification and corresponding changes in color and solubility of milk protein concentrate powder(MPC70) stored at 25 or40 ℃ and at 11,33 or 75%relative humidity(RH),respectively.Protein modifications in the soluble fractions were determined using liquid chromatography-mass spectrometry(LC-MS) and those in insoluble fractions using gel electrophoresis.The results showed that photo-oxidation caused significant decreases in L value.Moreover,the solubility of photo-oxidized MPC70 decreased significantly,while the MPC70 samples without UV exposure retained their solubility,except at 40 ℃ and 75%RH.For the soluble fractions of photo-oxidized MPC70,the MS spectra showed multiple additional fractions besides the un-and lactosylated intact protein fractions compared to control suggesting that the photo-oxidation induced further modifications of the proteins,which coincided with the formation of carbonyl groups in the protein.At low RH,photo-oxidation promoted lactosylation of β-lactoglobulin.The insoluble fractions of photo-oxidized MPC70 were mainly caseins as well as high molecular weight aggregates,resulting mainly from non-disulfide covalent crosslinks induced by photo-oxidation.The results suggested that photo-oxidation could induce the modification of protein that eventually contributed to the solubility loss and discoloration of MPC70.
The objective of this study was to investigate the effects of UV induced photo-oxidation on protein modification and corresponding changes in color and solubility of milk protein concentrate powder(MPC70) stored at 25 or40 ℃ and at 11,33 or 75%relative humidity(RH),respectively.Protein modifications in the soluble fractions were determined using liquid chromatography-mass spectrometry(LC-MS) and those in insoluble fractions using gel electrophoresis.The results showed that photo-oxidation caused significant decreases in L value.Moreover,the solubility of photo-oxidized MPC70 decreased significantly,while the MPC70 samples without UV exposure retained their solubility,except at 40 ℃ and 75%RH.For the soluble fractions of photo-oxidized MPC70,the MS spectra showed multiple additional fractions besides the un-and lactosylated intact protein fractions compared to control suggesting that the photo-oxidation induced further modifications of the proteins,which coincided with the formation of carbonyl groups in the protein.At low RH,photo-oxidation promoted lactosylation of β-lactoglobulin.The insoluble fractions of photo-oxidized MPC70 were mainly caseins as well as high molecular weight aggregates,resulting mainly from non-disulfide covalent crosslinks induced by photo-oxidation.The results suggested that photo-oxidation could induce the modification of protein that eventually contributed to the solubility loss and discoloration of MPC70.
引文
[1]H.M.Semagoto;Liu,D.;J.M.Regenstein;Zhou,P.Food Res Int.2014,62:580-588