Food Coloromics: Multi-spectral strategy incorporated with time slicing method and their colorant-oriented-searching workflows for black tea infusion

Abstract

Metabolomics approaches are frequently constrained by colorless variables for identifying chromogenic compounds. A novel multi-spectral strategy, combining diode-array detector absorption spectra with a newly developed time slicing method, was proposed as an effective tool for rapidly screening colored ingredients. This approach was demonstrated by analyzing black tea from different countries. Compared to conventional metabolomics, colorant-oriented-searching metabolomics significantly decreased analytical time, reduced false positive results by 35.45 %–71.06 %, improved analytical accuracy by 30.00 %–46.66 %, and provided additional spectral characteristics related to color. Furthermore, this approach successfully identified eight p-coumarylated flavonol glycosides with absorbance at 440–450 nm, exhibiting their role in contributing to the red hue of black tea infusions. The time slicing method, with optional parameters including color and intensity options, offered flexibility and high efficiency. Therefore, this approach provided a powerful tool and can readily be applied to search for novel colored ingredients in food science.