中国农业科学Issue(10)：2013-2020,8.DOI:10.3864/j.issn.0578-1752.2014.10.015
加热对鸡胸肉肌原纤维蛋白结构与凝胶特性的影响
Influence of Heating on Structure and Gel Properties of Myofibrillar Proteins from Chicken Breast Muscle
摘要
Abstract
ObjectiveThis study was designed to investigate the influence of heating on myofibrillar proteins(MP) secondary structure and gel properties, and to reveal the relationship between MP secondary structure and gel properties.[Method]Forty-day-old commercial AA broilers were slaughtered. The breast muscle was stored at-18℃ before MP was extracted. The MP secondary structure was measured using a circular dichroism spectra to determine the content ofα-helix,β-sheet,β-turn and random coil during heating. The values of G' and Tanδ were continuously measured using a rheometer during heating. The influence of heating temperature on textural properties of MP gel prepared under different temperatures was measured using a textural analyzer. Spin-spin relaxation time (T2) of the gels prepared under different temperatures was measured using a NMR Analyzer in order to investigate the water distribution of gels. SPSS17.0 software was used to analyze the data such as correlation analysis so as to illustrate the relationship between the heating temperature and protein structure and gel properties. [Result] Heating temperature influenced significantly MP secondary structure. Theα-helix content declined from 95.77%to 45.05%as temperature increased from 30℃ to 80℃. Theα-helix content declined slightly as temperature increased from 30℃ to 40℃ and from 70℃ to 80℃, declined abruptly between 40℃ and 70℃ (P<0.05). The β-sheet content increased from 0.20% to 12.65% as temperature increased from 30℃ to 80℃. The decline inα-helix content indicates the unfolding of a protein molecule. The increase inβ-sheet content indicates the aggregation of unfolding protein molecules. Heating temperature influenced rheological properties, textural properties and water distribution of MP. G' values began to increase at about 42℃ indicating the starting of protein gelling. G’ values showed a sharp increase between 42℃ and 50℃ (177 Pa) with a subsequent decrease between 50℃ and 55℃ and a final increase between 55℃and 75℃. Hardness values of MP gel increased as the temperature of the gel prepared rose from 40℃ to 75℃ and reached the maximum value of 51.4 g at 75℃. Springiness values reached the maximum value of 0.754 at 55℃. T2 curves of MP gel usually contained 3 peaks and T22 means immobile water. T22 values of the gels decreased from 403.7 ms to 265.6 ms as the gel preparing temperature rose from 40℃ to 60℃, which indicated that water mobility decreased as temperature rose from 40℃ to 60℃. Heating temperature andβ-sheet content showed a significant positive relationship to G' and hardness of gel (P<0.01), and the correlation coefficients were all over 0.849. The correlation analysis indicated that heating caused MP molecules unfolding, aggregating, gelling, and led to significant change of G' and hardness of MP gel. α-Helix and β-sheet, which didn't show a significant relationship to springiness and T22 of the MP gel. It was found that heating led to MP molecules unfolding, aggregating, gelling simultaneously at temperature over 40℃ by analyzing the influence of heating temperature on α-helix, β-sheet content and G’. The unfolding MP molecules rearranging toβ-sheet was the key factor for the increase of G’ values. The unfolding MP molecules rearranging toβ-sheet was also the key factor for the increase of hardness values by analyzing the influence of heating temperature onβ-sheet content and hardness values of MP gel.[Conclusion]Theα-helix content declined andβ-sheet content increased as temperature increased from 30℃ to 80℃. Heating led to significant changes of protein secondary structure. G' values began to increase and the values of Tanδbegan to decrease at about 42℃, which indicated the starting of protein gelling. Gel hardness values reached the maximum 51.4 g at 75℃. Heating temperature andβ-sheet content showed a significant positive relationship to G' and hardness of the gel. The increase ofβ-sheet content was the key factor for the increase of G’ and hardness values of the MP gel.关键词
肌原纤维蛋白/二级结构/加热温度/凝胶特性Key words
myofibrillar proteins/secondary structure/heating temperature/gel properties引用本文复制引用
杨玉玲,游远,彭晓蓓,陈银基..加热对鸡胸肉肌原纤维蛋白结构与凝胶特性的影响[J].中国农业科学,2014,(10):2013-2020,8.基金项目
国家自然科学基金面上资助项目 （）
