“…Since then, through over half a century of development, it has matured and is now widely employed in food, medicine, petrochemical, and other research fields (Mohamed et al, 2018 ; Guo et al, 2020 ). In recent years, NIR spectroscopy technology has become increasingly and broadly used in forestry, for example, to estimate photosynthetic characteristics (Dechant et al, 2017 ), to predict leaf-level nitrogen content (Kokaly, 2001 ), to distinguish bamboo shoots of different qualities (Tong et al, 2020 ), and to name a few applications. Partial least squares (PLS) regression, a quick, efficient, and optimal regression method based on covariance, is a widely used chemometric method, one that combines the advantages of multiple linear regression, canonical correlation analysis, and principal component regression (Tenenhaus et al, 2005 ; Sarker and Nichol, 2011 ).…”