ABSTRACT

Hair or bristle is one of the key by-products of humane slaughter of pigs. In the present study, Fourier-transform infrared (FTIR) spectroscopy was used for examining protein secondary structure of hair fiber from different breeds of pigs (Ghungroo, Ninag Megha, Hampshire, and Duroc). Prominent amide I (1635–1648 cm⁻¹) and amide II (1517–1528 cm ⁻¹) bands could be observed in the spectra. Differences in presence/absence of certain FTIR bands between breeds suggests influence of genetic background in the structure of hair fiber. Deconvolution resolved secondary structure of protein in amide I region of spectra into corresponding α-helix (38.0 ± 2.9%), β-sheets (32.2 ± 2.0%), β-turns (19.4 ± 3.1%) and unorganized structural components (10.3 ± 2.5%). Heating of fibers from 80°C to 120°C resulted in changes in amide regions and α-helix to β-sheet ratio of amide I band. Further, correlations were calculated between area under the curve of various FTIR bands and tensile properties of the fiber. Area of FTIR band at 1635 cm ⁻¹ was positively correlated with tenacity, initial modulus, extensibility, and work of rupture (r = 0.30 to 0.39). In nutshell, the study reveals subtle differences in secondary structure of hair with respect to breed or temperature treatment and suggests relation between FTIR spectral characteristics and tensile properties.

摘要

毛发或猪鬃是人道屠宰猪的主要副产品之一。在本研究中，傅里叶变换红外 (FTIR) 光谱用于检测不同品种猪（Ghungroo、Ninag Megha、Hampshire 和 Duroc）的毛发纤维的蛋白质二级结构。突出的酰胺 I (1635–1648 cm ^-1 ) 和酰胺 II (1517–1528 cm ^-1) 波段可以在光谱中观察到。品种间某些 FTIR 波段存在/不存在的差异表明遗传背景对毛发纤维结构的影响。反卷积将光谱酰胺 I 区域中蛋白质的二级结构分解为相应的 α-螺旋 (38.0 ± 2.9%)、β-折叠 (32.2 ± 2.0%)、β-转角 (19.4 ± 3.1%) 和无组织结构成分 (10.3 ± 2.5%）。将纤维从 80°C 加热到 120°C 会导致酰胺区域和酰胺 I 带的 α-螺旋与 β-折叠比率发生变化。此外，计算了各种 FTIR 波段曲线下面积与纤维拉伸性能之间的相关性。1635 cm ^{-1处的 FTIR 波段面积}与韧性、初始模量、延展性和断裂功呈正相关（r = 0.30 至 0.39）。简而言之，该研究揭示了头发二级结构在品种或温度处理方面的细微差异，并提出了 FTIR 光谱特性和拉伸特性之间的关系。