Systematic application of UPLC-Q-ToF-MS/MS coupled with chemometrics for the identification of natural food pigments from Davidson plum and native currant

This study investigates the potential of Australian Traditional foods as novel sources of natural colourants for food applications, employing untargeted metabolomics and chemometrics. Two native species were analysed: Davidson plum and native currant. The species were quantitatively assessed for colour properties using the CIELAB colour system in conjunction with Ultra Performance Liquid Chromatography-Quadrupole Time of Flight Tandem Mass Spectrometry (UPLC-Q-ToF-MS/MS). The results highlight diverse phenolic, flavonoid, and significant anthocyanin levels in Davidson plum and native currant, contributing to their robust red hues, comparable to commercial blueberry standards. Davidson plum and native currant exhibited high phenolic, flavonoid, and anthocyanin levels, contributing to vibrant red hues and significant bioactivity. Compared to blueberry, these species showed greater redness (a*) and chroma. Native currant demonstrated the highest phenolic content (146.73 mg g^-1), anthocyanin content (14.48 mg g^-1), and antioxidant activity (95.48 μmol Trolox equivalents/g). The chemometric analysis identified 46 key pigment metabolites, including anthocyanins and flavonoids, directly correlating to observed colour properties. UPLC-Q-ToF-MS/MS combined with CIELAB colourimetry facilitated pigment identification and colour analysis. These findings position Davidson plum and native currant as promising natural food colourants and functional ingredients. Additionally, the study underscores the efficacy of integrating chemometric analysis with CIELAB and UPLC-Q-ToF-MS/MS methodologies for pinpointing specific metabolites that influence the colour properties of these Traditional foods. This approach facilitates a deeper understanding of how indigenous Australian bushfoods can be innovatively incorporated into the food industry, aligning with consumer demand for natural and sustainable food options.