基于红外光谱分析热处理对牛乳蛋白质二级结构变化研究
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- 英文论文题名：Secondary structure changes of heat treatments on milk protein based on fourier transform infrared spectroscopy
- 论文作者：孙佳悦 ; 钱方 ; 牟光庆
- 英文论文作者：Sun Jiayue ; Qian Fang ; Mu Guangqing ; School of Food Science and Technology ; Dalian Polytechnic University
- 年：2016
- 作者机构：大连工业大学食品学院;
- 论文关键词：红外光谱技术 ; 热处理 ; 乳蛋白 ; 二级结构
- 英文论文关键词：FT-IR ; heat treatment ; thermal denaturation ; milk protein ; secondary structure
- 会议召开时间：2016-11-09
- 会议录名称：中国食品科学技术学会第十三届年会论文摘要集
- 英文会议录名称：Abstracts of the 13th Annual Meeting of CIFST
- 语种：中文
- 分类号：TS252.7
- 学会代码：ZGSP
- 会议名称：中国食品科学技术学会第十三届年会
- 会议地点：中国北京
- 主办单位：中国食品科学技术学会
- 学会名称：中国食品科学技术学会
- 页数：2
- 文件大小：101k
- 原文格式：O
- 会议级别：全国
摘要
运用傅里叶变换红外光谱(FT-IR)技术对乳蛋白及其酰胺Ⅰ带进行解析,进一步用红外解谱法对其二级结构进行表征。以原料乳为对照,研究65℃/30 min(低温长时巴氏杀菌)、80℃/15s(高温短时巴氏杀菌)、95℃/5 min(酸乳热处理)、137℃/5s(超高温灭菌)等不同热处理条件对乳中蛋白质二级结构的影响。结果表明,不同热处理程度的乳蛋白酰胺Ⅰ带均向低波数方向发生了不同程度的红移,说明热处理导致乳蛋白间发生相互作用,分子内氢键破坏,分子间形成较强的氢键作用力。同时热处理后乳蛋白各二级结构比例发生明显改变。α-螺旋含量降低,无规则卷曲含量显著增高,β-转角及β-折叠在加热过程均呈先增加后减少变化趋势,表明热处理程度增强导致部分有序结构向无规则卷曲结构转化,蛋白质热变性后会发生热聚集现象,且β-折叠和β-转角结构在热聚集体的形成过程中具有重要作用。
Heat treatment is a very important means of dairy processing.Different degree of heat treatment can change the physical and chemical properties of milk proteins in different level.Fourier transform infrared(FT-IR) spectroscopy was employed to investigate protein conformation changes,which proved that the variation of secondary structures of milk protein in the raw milk,pasteurized milk(65℃/30 min and 80℃/15s),yogurt(95℃/5 min) and ultra high temperature sterilized milk(137℃/5s).The result shows that different heat treatment conditions of milk protein amide I bands direction to low wave number band were occurred different level of red shift.It showed that heat treatment brought about milk protein interactions as well as intramolecular hydrogen bond broken,intermolecular strong hydrogen bonding produced.Meanwhile,the secondary structure of milk protein had certainly changed.During thermal denaturation,compared with untreated milk protein,the heat treatment resulted in reduction of α-helix structure and addition of random coil significantly.Moreover,β-sheet structure and β-turn structure showed a trend of increased firstly and then decreased.It was indicated that the degree of heat treatment led to the secondary structure of milk protein increasingly shifting from ordered structure toward random coil structure.Heating strengthening promoted aggregation of milk protein in the process of thermal denaturation,in addition β-sheet and β-turn played an important role in the process of the formation of thermal aggregate.
Heat treatment is a very important means of dairy processing.Different degree of heat treatment can change the physical and chemical properties of milk proteins in different level.Fourier transform infrared(FT-IR) spectroscopy was employed to investigate protein conformation changes,which proved that the variation of secondary structures of milk protein in the raw milk,pasteurized milk(65℃/30 min and 80℃/15s),yogurt(95℃/5 min) and ultra high temperature sterilized milk(137℃/5s).The result shows that different heat treatment conditions of milk protein amide I bands direction to low wave number band were occurred different level of red shift.It showed that heat treatment brought about milk protein interactions as well as intramolecular hydrogen bond broken,intermolecular strong hydrogen bonding produced.Meanwhile,the secondary structure of milk protein had certainly changed.During thermal denaturation,compared with untreated milk protein,the heat treatment resulted in reduction of α-helix structure and addition of random coil significantly.Moreover,β-sheet structure and β-turn structure showed a trend of increased firstly and then decreased.It was indicated that the degree of heat treatment led to the secondary structure of milk protein increasingly shifting from ordered structure toward random coil structure.Heating strengthening promoted aggregation of milk protein in the process of thermal denaturation,in addition β-sheet and β-turn played an important role in the process of the formation of thermal aggregate.
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