Silver-Based Nanofilms Show Promise in Reducing Synthetic Food Dye Risks in Soft Drinks

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Synthetic food dyes are used in a variety of soft drinks, but their impact on human health is considered negative. A recent study that was published in the journal Applied Food Research explored the impact of synthetic food dyes (1). In the study, a team of researchers from the Vellore Institute of Technology-Vellore (India) used advanced analytical techniques to study the harmful compounds found in popular soft drinks and the potential of polyvinyl alcohol-silver (PVA-Ag) nanofilms to mitigate these risks.

According to nutritionists, modern dietary choices, which include consuming foods high in calories and replete in nutrients, often lead to health problems such as obesity, high blood pressure, diabetes, heart disease, and even cancer (2). Food-grade dyes play a role in contributing to these health conditions. Although using synthetic food dyes are legally permissible for the most part, they can cause damage to the gut microbiome, liver, kidney, pancreas, and nervous system (1). Some products also contain non-permitted dyes, further raising concerns about consumer safety (1).

The researchers investigated these risks by analyzing several soft drink samples using techniques such as UV–vis spectroscopy, gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FT-IR), and high-performance liquid chromatography (HPLC) (1). By using these methods, the researchers were able to detect the presence of both permitted and non-permitted synthetic colorants, including erythrosine, sunset yellow, carmoisine, caramel 150D, tartrazine, brilliant blue, and Allura red (1).

The study also investigated whether PVA-Ag nanofilms could act as effective absorbents of these dyes. Small nanofilm samples (1 × 1 cm) were incubated in soft drinks for three days, with the researchers monitoring any changes using UV–vis spectroscopy (1). The results showed a significant reduction in dye concentration over time, suggesting that the nanofilms can absorb a wide range of synthetic colorants (1).

Based on their findings, the researchers believe these nanofilms can be used in industries such as cosmetics and pharmaceuticals, which used synthetic dyes often in their products. However, the researchers caution that more work is needed to assess long-term efficiency, scalability, and the shelf life of the films when used in large sample volumes (1).

References

1. Rajkumar, R.; Rejith, A. V. P.; Ramasubba, K.; et al. Analysis of Marketed Soft Drinks and Reduction of Food Colours with a Simple Absorption Technique with PVA-Ag nanofilms. Appl. Food Res. 2025, 5 (1), 100779. DOI: 10.1016/j.afres.2025.100779
2. Cena, H.; Calder, P. C. Defining a Healthy Diet: Evidence for the Role of Contemporary Dietary Patterns in Health and Disease. Nutrients 2020, 12 (2), 334. DOI: 10.3390/nu12020334