农业工程学报2016，Vol.32Issue(8)：285-291,7.DOI:10.11975/j.issn.1002-6819.2016.08.040
热处理强度对猪肉肌球蛋白结构及风味成分吸附特性的影响
Effect of heat treatment intensity on structure and binding capacity of volatile compounds of myosin
摘要
Abstract
In this paper, myosin in pork was extracted as the object of the research, and the purity of the protein was analyzed by sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE); the effects of variable heating strength on the total sulfydryl content (T-SH), the secondary structure and the surface hydrophobicity of myosin were detected by Raman spectroscopy and fluorescence spectroscopy. Eight typical meat flavor compounds were added to the myosin solutions to form a myosin-flavor compound interaction system. Taking the ratio of flavor compounds relative content as index, the influence of different heating strength on the flavor binding ability of myosin was studied by means of solid-phase microextraction - gas chromatography - mass spectrometry (SPME-GC-MS), providing a reference for future research on the formation mechanism of meat flavor. The results showed that heat treatment had significant effect on the absorption and release of various flavor compounds, through changing myosin conformation to hit the mark what we wanted to achieve; when the temperature was adjusted up to 55℃, the myosin molecules were unfolded obviously, resulting a conversion fromα-helix andβ-sheet toβ-turn and random coil. However, as the temperature continued to increase to 75℃, the myosin molecules degenerated and the process showed the reverse change, that was to say, there was a transition fromβ-turn and random coil toα-helix andβ-sheet. In the procedure when the temperature was raised to 45℃, the amount of protein sulfydryl group remained stable, but there was a marked reduction when further improving the temperature to 80℃, resulted in protein aggregating because a small part of sulfydryl converted to disulfide bond; the surface hydrophobicity of myosin continued to increase dramatically during the course of the temperature going up to 65℃ and then many hydrophobic residue groups would be exposed at the molecular surface, however, when the temperature rose, its surface hydrophobicity decreased slightly, indistinctively; myosin’s binding ability to 3-methyl butaldehyde, pentanal, heptanal and octanal was enhanced with the protein unfolding and decreased with the protein degenerating. Besides the hydrophobic group and hydrogen bond, sulfydryl group played a considerable role in affecting the binding ability of myosin to aldehydes. On the one hand, the binding ability of myosin to 2-pentanone presented a trend of first decreasing and then increasing on the whole, in which it showed the lowest binding ability under the condition of 45℃ and the fastest binding under 85℃; on the other hand, their binding ability between myosin and 2-heptanone, 2-octanone or 2-nonanone demonstrated a trend of increasing, decreasing, and then increasing again, and the binding ability reduced to the minimum while myosin degenerated at the temperature of 75℃, and the binding ability rose to the highest at the temperature of 85℃ compared to other conditions. To sum up, the binding ability of myosin to ketones mainly depends on the hydrophobic properties.关键词
温度/蛋白/风味/热处理/肌球蛋白/巯基总量/二级结构/表面疏水性Key words
temperature/protein/flavors/heat treatment/myosin/total sulphydryl content/secondary structure/surface hydrophobicity分类
轻工纺织引用本文复制引用
吕彤,林俊杰,周昌瑜,王颖,曹锦轩,潘道东..热处理强度对猪肉肌球蛋白结构及风味成分吸附特性的影响[J].农业工程学报,2016,32(8):285-291,7.基金项目
宁波市创新团队（2012B82017），国家农业科技成果转化资金项目（2013GB2C200191），国家自然科学基金资助项目（31471681）。 （）
