食品科学 ›› 2018, Vol. 39 ›› Issue (20): 43-48.doi: 10.7506/spkx1002-6630-201820007

• 食品化学 • 上一篇    下一篇

丙烯醛氧化修饰对核桃蛋白结构和乳化特性的影响

孙领鸽,王丹丹,毛晓英*,詹萍,田洪磊   

  1. (石河子大学食品学院,新疆?石河子 832000)
  • 出版日期:2018-10-25 发布日期:2018-10-24
  • 基金资助:
    国家自然科学基金地区科学基金项目(31560433)

Influence of Oxidative Modification with Acrolein on Structural and Emulsifying Properties of Walnut Protein

SUN Lingge, WANG Dandan, MAO Xiaoying*, ZHAN Ping, TIAN Honglei   

  1. (College of Food, Shihezi University, Shihezi 832000, China)
  • Online:2018-10-25 Published:2018-10-24

摘要: 采用不同浓度(0~1?mmol/L)的丙烯醛代表多不饱和脂肪酸在脂肪氧合酶诱导下发生脂质过氧化反应过程中产生的小分子醛类物质,研究脂质活性氧化产物丙烯醛氧化对核桃蛋白结构和乳化特性的影响。结果表明,随着丙烯醛浓度的增加,核桃蛋白羰基含量从4.287?nmol/mg显著增加到11.078?nmol/mg。游离巯基和总巯基含量分别下降了55.18%和31.13%,说明丙烯醛使核桃蛋白发生了显著氧化。随着核桃蛋白氧化程度的增加,溶解度下降了84%;表面疏水指数从469.47下降到412.22;β-折叠、α-螺旋(有序)结构相对含量减少,β-转角、无规则卷曲(无序)结构相对含量增加。同时,核桃蛋白的乳化性和乳化稳定性分别从46.87?m2/g和25.93?min下降至9.86?m2/g和17.63?min。研究结果说明丙烯醛氧化能够导致核桃蛋白发生结构性氧化修饰,从而引起其乳化特性的变化。

关键词: 丙烯醛, 蛋白氧化, 核桃蛋白, 结构, 乳化特性

Abstract: In order to investigate the effect of oxidative modification with reactive aldehyde on the structural and emulsifying properties of walnut protein, acrolein (0–1 mmol/L) was selected as a representative secondary byproduct of lipid peroxidation induced by lipoxygenase (LOX) for incubation with walnut protein. The results showed that the carbonyl content of walnut protein significantly increased from 4.287 to 11.078 nmol/mg with increasing aldehyde concentration, accompanied by a decrease in free sulphydryl and total sulphydryl by 55.18% and 31.13%, respectively suggesting that acrolein caused significant changes to walnut protein. The solubility of walnut protein decreased by up to 84% with the increase in its degree of oxidation, and the surface hydrophobicity declined from 469.47 to 412.22; the contents of α-helix and β-sheet increased, while the contents of β-turn and random coil decreased. In addition, the emulsifying capacity and emulsion stability of walnut protein decreased from 46.87 to 9.86 m2/g and from 25.93 to 17.63 min, respectively. All of these results indicate that acrolein can lead to oxidative structural modification of walnut protein, thus causing damage to the emulsifying properties of the protein.

Key words: acrolein, protein oxidation, walnut protein, structure, emulsifying properties

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