宣恩火腿加工过程中蛋白质相互作用力变化

Changes in Protein Interactions during Xuanen Ham Processing

将宣恩火腿加工过程分为5个阶段,分析测定不同阶段蛋白质相互作用力的变化情况,研究结果表明:对于原料腿而言,维持蛋白质结构稳定的化学作用力以疏水相互作用和离子键为主,而成品腿以疏水相互作用和二硫键为主,在加工过程中离子键和氢键相对含量下降,疏水相互作用和二硫键相对含量上升。从原料腿到成品腿,肌原纤维蛋白溴酚蓝结合量从9.09μg增加到38.7μg,而表征蛋白质氧化程度的羰基值从原料腿的0.68 nmol/mg增加到成品的2.28 nmol/mg,变化趋势与表面疏水性变化趋势保持一致,表面疏水性的增加可能与蛋白质的氧化有关。宣恩火腿加工过程中巯基暴露后被氧化形成二硫键,其含量从原料腿的9.65 nmol/mg增加到成品的21.6 nmol/mg。表面疏水性、二硫键是维持蛋白质三级结构稳定的重要作用力,正是这些作用力的增强,导致宣恩火腿在漫长的发酵期内依然维持其结构和功能的稳定。

Xuanen ham processing was divided into five stages,and changes in protein interactions at each stage were determined and analyzed.Interactions were mediated primarily by hydrophobic effects and ionic bonds in the raw leg.Interactions in finished hams were largely mediated by hydrophobic effects and disulfide bonds.During processing,the relative content of ionic and hydrogen bonds decreases,while the relative content of hy-drophobic interactions and disulfide bonds increases.From the raw leg to the finished ham,the bromophenol blue binding myofibrillar protein content increased from 9.09μg to 38.7μg.The increase in surface hydropho-bicity may be related to protein oxidation.The carbonyl conten(t characteristic of the degree of protein oxidation)increased from 0.68 nmol/mg in the raw leg,to 2.28 nmol/mg in the finished ham.This trend was consistent with the observed change in surface hydrophobicity.During the processing of Xuanen ham,sulfhydryl groups were oxidized upon exposure,forming disulfide bonds.Disulfide bond content increased from 9.65 nmol/mg in the raw leg,to 21.6 nmol/mg in finished ham.Surface hydrophobicity and disulfide bonds were important forces that sta-bilize protein tertiary structures.Enrichment in these forces contributes to the stability of Xuanen ham structure and function during its long fermentation period.