Food Additive Testing

Wang, Jianghua, et al. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 324 (2025): 125036.

Sodium tripolyphosphate (STPP) is a common food additive that, when ingested, can cause gastrointestinal discomfort and various adverse reactions, posing a potential health risk. Therefore, developing a fast, sensitive, and simple method to detect STPP in food is crucial.

In this study, nitrogen-doped carbon quantum dots (N-CQDs) were found to exhibit a gradual increase in emission peaks upon the addition of STPP, with a good linear response in the concentration range of 0.067–1.96 μM and a low detection limit of 0.024 μM. To the best of our knowledge, this is the first report of using carbon quantum dots for the direct detection of STPP. Additionally, the addition of Al³⁺ significantly reduced the fluorescence intensity of the N-CQDs@STPP solution, showing a good linear correlation in the 0.33–6.25 μM range, with a detection limit of 0.24 μM. This fluorescent probe was successfully applied to detect STPP and Al³⁺ in bread samples, demonstrating its great potential for practical application.

Zhang, Yumiao, et al. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 323 (2024): 124879.

A novel composite SERS substrate, consisting of AuNPs and NPG, has been developed for the rapid detection of 6-BA in food samples, offering a simple, sensitive, and reproducible method.

In this study, AuNPs with a particle size range of 60-90 nm were synthesized for SERS detection of varying concentrations of 6-BA solutions. SERS spectra were collected from 6-BA solutions at different concentrations, with the minimum detection concentration of 6-BA being 10⁻⁶ M. When compared to the conventional Raman spectra of 6-BA powder, the SERS spectra obtained using AuNPs as the substrate revealed distinct characteristic peaks at 740 cm⁻¹ (symmetric deformation breathing vibration of the amidopurine ring), 813 cm⁻¹ (ring respiration vibration), 1000 cm⁻¹ (stretching breathing vibration of monosubstituted benzene ring skeleton), 1128 cm⁻¹ (R₂NH symmetric stretching vibration), 1314 cm⁻¹ (C-N axial stretching vibration), 1403 cm⁻¹ (CH deformation vibration), and 1465 cm⁻¹ (ring stretching vibration). The strongest peak at 1000 cm⁻¹ was identified as the characteristic peak for 6-BA.

Kamaraj, Jeffrey Joseph John Jeya, et al. Journal of the Taiwan Institute of Chemical Engineers 162 (2024): 105601.

The use of synthetic phenolic antioxidants, such as Propyl gallate (PG), in food products has raised concerns due to their potential impact on the nutraceutical properties of various foods. PG is commonly added to cooking oils, cheese, cookies, and other oil-based products to prevent fatty acid peroxidation, thus reducing fatty acid degradation and rancidity. However, excessive PG consumption can lead to serious health issues, including mitochondrial dysfunction and damage to the liver and kidneys. Therefore, monitoring PG levels in food products is crucial.

In this study, CoSe₂ nano corals and FeS₂ nanosheets were synthesized through a hydrothermal process and combined to create an electrochemical sensor for PG detection. The effect of PG concentrations ranging from 50 to 500 μM on the current response was measured using cyclic voltammetry (CV) in 0.01 M phosphate buffer (pH 7.0) at a scan rate of 50 mVs^-1. The results demonstrated a gradual increase in current response with higher PG concentrations, indicating faster electron transfer kinetics at the modified glassy carbon electrode (GCE). The corresponding linear relationship between current and PG concentration was established, with the equation Ipa = 0.03095x(μM) + 1.824 and a coefficient of determination (R²) of 0.99783.