Distinguishing yak and cashmere fibers from each other to prohibit mislabeling through microscopic and spectroscopic analysis

Abstract

Since yak and cashmere fibers show very similar properties and yak fibers are considerably cheaper than cashmere, it is an important issue that yak is used instead of cashmere in the industry and the final product is sold as cashmere with misleading labelling. Therefore, researchers have been working on developing a method for differentiating these two fibers for many years. In the studies carried out in literature to date, no definitive method has been found which can distinguish these fibers from each other. Accurate results can only be obtained with DNA analysis, and this method is difficult and expensive to apply. On the other hand, when the literature was examined, it was seen that various fiber properties were investigated to distinguish yak and cashmere fibers. However, fibers having the same color were not systematically used together in these studies. In this study, both white and brown fibers from cashmere and yak origin were examined and thus, whether any method would be useful or not to distinguish yak and cashmere fibers in general or white cashmere from white yak and brown cashmere from brown yak in particular was presented. Within the scope of present work, it was aimed to find a way of distinguishing these fibers from each other by making various microscopic and spectroscopic analysis. For this aim fiber cross-section and longitudinal appearance analysis by light microscopy; scale morphology (scale structure, scale shape, scale pattern), scale height (thickness), scale length and scale frequency analysis by scanning electron microscopy; color (CIE L*a*b* color coordinates) analysis with spectrophotometer, fiber functional group analysis by Fourier transform infrared spectroscopy and fiber combustion behavior analysis with thermogravimetric analysis were conducted.