  A chemometric data analysis challenge has been arranged during the first
edition of the "International Workshop on Spectroscopy and Chemometrics",
organized by the Vistamilk SFI Research Centre and held online in April 2021.
The aim of the competition was to build a calibration model in order to predict
milk quality traits exploiting the information contained in mid-infrared
spectra only. Three different traits have been provided, presenting
heterogeneous degrees of prediction complexity thus possibly requiring
trait-specific modelling choices. In this paper the different approaches
adopted by the participants are outlined and the insights obtained from the
analyses are critically discussed.
