Determination of the Fatty Acid Composition in Tree Peony Seeds Using Near‐Infrared Spectroscopy

Abstract

Abstract Tree peonies ( Paeonia Sect Moutan DC) are an emerging oil crop because of their high oil and α‐linolenic acid (ALA) content. This research was to investigate the potential use of near infrared reflectance spectroscopy (NIRS) for estimating the major fatty acids contents, such as palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3) in tree peonies. A total of 115 small seed samples and 447 single seeds were selected to calibrate the predictive models. NIRS absorbance spectra were collected using a Fourier transform near infrared (FT‐NIR) spectrometer for the small seed samples, and acousto‐optic tunable filter‐near infrared (AOTF‐NIR) for the single seed samples. Statistical analysis was performed with partial least squares (PLS). For the husked samples, C18:3, C18:1 and C18:2 showed the highest correlation coefficient of validation ( R v ; = 0.9756, 0.9467 and 0.8485, respectively) and the ratio of performance to deviation (RPD; = 3.58, 1.91 and 2.17, respectively); however, C16:0 did not reach expectations ( R v = 0.7783, RPD = 1.32). For intact samples, C18:3 showed the best prediction ( R v = 0.9096, RPD = 3.14), followed by C18:2 ( R v = 0.8479, RPD = 1.96). The results for C18:1 were poor ( R v = 0.7237, RPD = 1.70). For single seeds, only the results for C18:3 ( R = 0.9150, RPD = 1.73) were good in the husked seed samples. It was concluded that NIRS can be used to rapidly assess the content of the major fatty acids in small samples.