Toward Food Freshness Monitoring: Coordination Binding-Based Colorimetric Sensor Array for Sulfur-Containing Amino Acids.

Xiaojun Lyu,Wei Tang,Tsuyoshi Minami,Yui Sasaki,Tingting Zheng,Yang Tian,Jie Zhao

doi:10.3389/fchem.2021.685783

Xiaojun Lyu, Wei Tang + Show 5 more

Open Access

https://doi.org/10.3389/fchem.2021.685783

Copy DOI

Abstract

Herein, a self-assembled colorimetric chemosensor array composed of off-the-shelf catechol dyes and a metal ion (i.e., Zn2+) has been used for the sulfur-containing amino acids (SCAAs; i.e., glutathione, glutathione disulfide, L–cysteine, DL–homocysteine, and L–cystine). The coordination binding–based chemosensor array (CBSA) fabricated by a competitive assay among SCAAs, Zn2+ ions, and catechol dyes [i.e., pyrocatechol violet (PV), bromopyrogallol red (BPR), pyrogallol red (PR), and alizarin red S (ARS)] yielded fingerprint-like colorimetric changes. We succeeded in the qualification of SCAAs based on pattern recognition [i.e., a linear discrimination analysis (LDA)] with 100% correct classification accuracy. The semiquantification of reduced/oxidized forms of SCAAs was also performed based on LDA. Furthermore, we carried out a spike test of glutathione in food samples using the proposed chemosensor array with regression analysis. It is worth mentioning that we achieved a 91–110% recovery rate in real sample tests, which confirmed the accuracy of the constructed model. Thus, this study represents a step forward in assessing food freshness based on supramolecular analytical methods.

Highlights

To date, there is an increasing demand from consumers to evaluate the safety of food products
We quantified the pseudo-oxidation processes of sulfur-containing amino acids (SCAAs) in aqueous media and predicted the GSH concentration in tomato and grapefruit juice (Minich and Brown, 2019). These results indicate that our simple preparation and user-friendly sensing system could achieve high-throughput analysis for SCAAs, which would be a step forward for assessing food freshness based on supramolecular analytical methods
The result of the semiquantitative analysis and the spike test indicated that the chemosensor array combined with pattern recognition could be applied for quantifying unknown GSH concentrations, which suggests that the proposed method would become a rapid and promising method for the detection of SCAAs in food samples

Summary

INTRODUCTION

There is an increasing demand from consumers to evaluate the safety of food products. To simplify the sensing procedures, chemosensors have become a promising option, which can exhibit optical property changes based on molecular recognition (Hyman and Franz, 2012; Lee et al, 2015; Wu et al, 2015; Yan et al, 2017; Khorasani et al, 2019; Roy, 2021) In this regard, several optical chemosensors have been developed for natural amino acids (Buryak and Severin, 2005; Ma et al, 2013; Yin et al, 2013; Sener et al, 2014; Ghasemi et al, 2015; Meng et al, 2015; Chao and Zhang, 2017; Gholami et al, 2019; Liu et al, 2019; Xu et al, 2020). We quantified the pseudo-oxidation processes of SCAAs in aqueous media and predicted the GSH concentration in tomato and grapefruit juice (Minich and Brown, 2019) These results indicate that our simple preparation and user-friendly sensing system could achieve high-throughput analysis for SCAAs, which would be a step forward for assessing food freshness based on supramolecular analytical methods

MATERIALS AND METHODS

CONCLUSION

Findings

DATA AVAILABILITY STATEMENT