糟蛋减压加工过程中蛋黄蛋白质二级结构的变化研究

Changes in Yolk Protein Secondary Structure of the Preserved Egg in Wine during Low Pressure-vacuum Processing

摘要:

本研究通过减压抽真空技术加工糟蛋，采用FTIR研究糟蛋加工过程中不同时期的蛋黄中蛋白质二级结构含量变化。结果显示：在糟蛋腌制过程中，α螺旋和无规则卷曲含量变化不明显；而β折叠和β转角在腌制过程中互相转化，在腌制30 d时变化最为明显：β折叠含量明显上升至37.70%，β转角明显下降至16.32%。研究结果表明糟蛋在腌制初期，蛋黄蛋白质在酸性条件、钙离子以及钠离子的影响下，蛋白质天然结构展开，蛋白质分子间的次级键断裂，蛋白质肽链结构打开，二级结构含量发生变化;而在腌制后期，pH值保持恒定，蛋白质二级结构恢复，与生蛋含量基本一致。

Abstract:

The research examined the secondary structure of yolk proteins of the egg preserved in wine and treated by low pressure vacuum for 0-45 days, using Fourier transformed infrared spectrum (FTIR). Noticeable changes in β-sheet ( up to 37.70%) and β-turns (reduce to 16.32%) were found when the egg pickled for 30 days. The structures of β-sheet and β-turns were transformational with each other during pickling. On the other hand, the content of α-helix and random coils had little changes. The results indicated the secondary bonds of yolk proteins of egg preserved in wine were broken effected by ionic strength (Ga2+ and Na+) under acid conditions. The results also showed the degeneration of yolk proteins were accelerated by low pH and ionic strength.