Detection of Blackcurrant Adulteration by Aronia Berry Using High Resolution Mass Spectrometry, Variable Selection and Combined PLS Regression Models

Abstract

Aronia berry has a deep red colour, and as it is cheaper than blackcurrant, it may be used to adulterate blackcurrant juice and drinks made therefrom. The aim of the study was to produce a model using multivariate tools to quantify the level of adulteration of blackcurrant concentrates with aronia berry concentrates. Samples of various blends between the two fruits were analysed after dilution on an ultra high pressure liquid chromatography-time of flight mass spectrometry (UPLC-TOF-MS) to create partial least squares (PLS) models. Moreover, variable selection was investigated with the recursive weighted PLS (rPLS) method to increase PLS model quality, and different levels of fusion between data from the two ionisation modes were also compared. The best model was obtained from fusion of ionisation modes with variable selection using the rPLS method. The limit of detection of 5 % aronia berry concentrate in blackcurrant concentrate was achievable with ±1 % error on the adulteration level.