Determination of active constituents in kombucha fermentation broth using nano-composite colorimetric sensor based on selected volatile markers determined by GC-MS

Herein, a nano-composite colorimetric sensor array (Nano-CSA) coupled with near infrared (NIR) spectroscopy was developed for the determination of active constituents. Sixty-seven volatile compounds of seven chemical groups were determined as markers in the kombucha broth by headspace-solid phase microextraction- gas chromatography-mass spectrometry (HS-SPME-GC-MS). A nano-CSA composed of chemically responsive dyes doped metal-organic frameworks (MOF) was fabricated to obtain sensitive interaction with different volatile markers. Kombucha broth samples with different fermentation times were separated using chemometric methods Compared to these partial least squares (PLS) analyses, competitive adaptive reweighted sampling-PLS (CARSPLS) performed optimally for the detection of tea polysaccharides (TPSs) with a prediction set (Rp) correlation coefficient of 0.9007. Despite the better performance of the CARS-PLS towards tea polyphenols (TPPs) with a Rp of 0.9144, the novel nano-CSA-NIRs provides the basis for the optimal results and a reliable system to estimate the chemical and physical properties of tea fermentation broth.

Automated summary

A nano-composite colorimetric sensor array coupled with near infrared spectroscopy was developed for the determination of active constituents. The sensor array, composed of chemically responsive dyes doped metal-organic frameworks, showed sensitive interaction with different volatile markers. Chemometric methods were used to separate kombucha broth samples with different fermentation times, enabling the estimation of the chemical and physical properties of tea fermentation broth.