Zhang Xuewei, Yu Peiqiang
College of Animal Science and Animal Veterinary, Tianjin Agricultural University , Tianjin 300384, People's Republic of China.
J Agric Food Chem. 2014 Jul 2;62(26):6199-205. doi: 10.1021/jf501553g. Epub 2014 Jun 23.
Non-invasive techniques are a key to study nutrition and structure interaction. Fourier transform infrared microspectroscopy coupled with a synchrotron radiation source (SR-IMS) is a rapid, non-invasive, and non-destructive bioanalytical technique. To understand internal structure changes in relation to nutrient availability in oil seed processing is vital to find optimal processing conditions. The objective of this study was to use a synchrotron-based bioanalytical technique SR-IMS as a non-invasive and non-destructive tool to study the effects of heat-processing methods and oil seed canola type on modeled protein structure based on spectral data within intact tissue that were randomly selected and quantify the relationship between the modeled protein structure and protein nutrient supply to ruminants. The results showed that the moisture heat-related processing significantly changed (p<0.05) modeled protein structures compared to the raw canola (control) and those processing by dry heating. The moisture heating increased (p<0.05) spectral intensities of amide I, amide II, α-helices, and β-sheets but decreased (p<0.05) the ratio of modeled α-helices to β-sheet spectral intensity. There was no difference (p>0.05) in the protein spectral profile between the raw and dry-heated canola tissue and between yellow- and brown-type canola tissue. The results indicated that different heat processing methods have different impacts on the protein inherent structure. The protein intrinsic structure in canola seed tissue was more sensitive and more response to the moisture heating in comparison to the dry heating. These changes are expected to be related to the nutritive value. However, the current study is based on limited samples, and more large-scale studies are needed to confirm our findings.
非侵入性技术是研究营养与结构相互作用的关键。傅里叶变换红外显微光谱与同步辐射光源相结合(SR-IMS)是一种快速、非侵入性且无损的生物分析技术。了解油料种子加工过程中与养分有效性相关的内部结构变化对于找到最佳加工条件至关重要。本研究的目的是使用基于同步辐射的生物分析技术SR-IMS作为一种非侵入性和无损工具,基于随机选择的完整组织内的光谱数据,研究热处理方法和油菜籽类型对模拟蛋白质结构的影响,并量化模拟蛋白质结构与反刍动物蛋白质养分供应之间的关系。结果表明,与未加工的油菜籽(对照)和干热加工的油菜籽相比,湿热相关加工显著改变了(p<0.05)模拟蛋白质结构。湿热增加了(p<0.05)酰胺I、酰胺II、α-螺旋和β-折叠的光谱强度,但降低了(p<0.05)模拟α-螺旋与β-折叠光谱强度的比值。未加工和干热加工的油菜籽组织之间以及黄色和棕色油菜籽组织之间的蛋白质光谱特征没有差异(p>0.05)。结果表明,不同的热处理方法对蛋白质固有结构有不同的影响。与干热相比,油菜籽组织中的蛋白质固有结构对湿热更敏感,反应更强烈。这些变化预计与营养价值有关。然而,目前的研究基于有限的样本,需要更多大规模研究来证实我们的发现。