低温贮藏对鸡胸肉肌原纤维蛋白结构及热诱导凝胶性能的影响

Effects of low temperature storage on the structure and heat-induced gelation properties of myofibrillar protein prepared from chicken breast muscle

中文关键词:  鸡胸肉  肌原纤维蛋白  低温贮藏  热诱导凝胶  分子间作用力

英文关键词:chicken breast muscle  myofibrillar protein  low tempertaure storage  heated-induced gelation  intermolecular force

中文摘要:

      目的 研究4 ℃(冷藏)与?18 ℃(冷冻)贮藏条件对鸡胸肉肌原纤维蛋白(myofibrillar protein, MP)结构及热诱导凝胶性能的影响。方法 通过测定总巯基、钙离子ATP酶(calcium-ATPase, Ca2+-ATPase)活性、表面疏水性、凝胶质构、保水性等指标衡量MP结构及凝胶特性的变化, 并从分子间作用力及蛋白质构象角度阐述贮藏条件对MP热诱导凝胶机制的影响。结果 在4 ℃与和?18 ℃贮藏环境下, 随着贮藏时间的延长, MP总巯基含量减少, 表面疏水性上升, Ca2+-ATPase酶活性降低。其次, MP热诱导凝胶中离子键及氢键作用力也随贮藏时间的延长而呈下降趋势, 而疏水作用力呈上升趋势; 凝胶中的α-螺旋和β-折叠含量呈下降趋势, 而β-转角与无规则卷曲含量呈上升趋势。结论 低温贮藏期间MP结构发生劣变, 蛋白凝胶结构由有序转向无序结构, 导致凝胶质构、保水性下降; 相较4 ℃贮藏, ?18 ℃能够更好地长时间维持MP结构和凝胶特性。

英文摘要:

      Objective To study the effects of 4 ℃ (chilled) and ?18 ℃ (frozen) storage conditions on the structure and heat-induced gelation properties of chicken breast muscle myofibrillar protein (MP). Methods The changes of MP structure and gel properties were characterized by total sulfhydryl content, the activity of calcium-ATPase (Ca2+-ATPase), the surface hydrophobicity, gel texture and water holding capacity, and the effects of different storage conditions on heat-induced gelation mechanism of MP were studied from the perspectives of protein conformation and intermolecular bonds. Results The total sulfhydryl content of MP and the activity of Ca2+-ATPase decreased while the surface hydrophobicity increased with the extension of storage time at 4 ℃ and ?18 ℃. In the determination of intermolecular force, the ionic bond and hydrogen bond of gel decreased during the storage, while the hydrophobic force was increased; meanwhile, the content of α-helix and β-sheet decreased with the increase of storage time, but the content of β-turn and random coil increased. Conclusion During low temperature storage, the structure of MP deteriorate, and the structure of protein gel changes from order to disorder, resulting in the decrease of gel texture and water retention; compared with 4 ℃ storage, ?18 ℃ can better maintain the structure and gel properties of MP for a long time.