葡萄糖氧化酶对面团水分状态及蛋白质结构的影响

Effect of Glucose Oxidase on Moisture Status and Protein Structure of Dough

采用核磁共振和傅立叶变换红外光谱技术,研究了葡萄糖氧化酶（0~0.5%）对面团水分分布状态和蛋白质结构参数变化的影响,并结合面团热力学特性和二硫键含量变化对各实验指标进行相关性分析。结果表明：添加葡萄糖氧化酶可降低面团T2弛豫时间,在0~0.5%范围内,T21和T22呈现先减小后增大的趋势,添加量为0.4%时,T21、T22测定值最小,且添加量与T21和T22具有显著负相关（p〈0.05）;β-折叠片层、β-折叠、α-螺旋、无序结构和β-转角含量先增加后降,且添加量与r具有极显著正相关（p〈0.01）;葡萄糖氧化酶可提高面团糊化温度,增强面团热稳定性,并促使面团体系中的-SH转化为S-S,且对S-S变化影响显著（p〈0.05）;面团中水分迁移与面团糊化温度、二硫键（S-S）含量、α-螺旋、β-转角和无序结构均具有显著相关性（p〈0.05）;团糊化峰值温度（Tp）与S-S、α-螺旋和β-转角具有显著正相关（p〈0.05）。

Nuclear Magnetic Resonance（NMR） and Fourier transform infrared spectroscopy（FT-IR） were used to study the effect of glucose oxidase（GOD）（0~0.5%） on moisture distribution and parameter changes of protein structures in dough. A correlation analysis of each experimental indicator was conducted based on the thermodynamic properties of dough and the changes in disulfide bond content. The results showed that the addition of GOD could reduce the relaxation times（T2） for water in dough. In the range of 0~0.5%, the T21 and T22 values decreased first and then increased, whereas when the dose was 0.4%, the measured T21 and T22 values were the lowest; thus, GOD concentration had a significant negative correlation（p 〈 0.05） with T21 and T22. The amount of β-pleated sheet, β-sheet, α-helix, unordered structure, and β-turn increased first and then decreased, and a significant positive correlation（p 〈 0.01） was found between GOD concentration and r values. GOD could increase the gelatinization temperature and thermal stability of the dough, promote sulfhydryl groups（-SH） to be converted to disulfide groups（S-S）, and significantly affect changes in disulfide groups（S-S）. The moisture migration in dough showed significant correlation（p 〈 0.05） with the gelatinization temperature of dough, disulfide（S-S） content, α-helix, β-turn, and unordered structure. The gelatinization peak temperature（Tp） had significant positive correlation with disulfide groups（S-S）, α-helix, and β-turn（p 〈 0.05）.