Development of Sustainable Paper Based Indicator Strip for Detection of Adulteration in Milk and Fish

Abstract

The increasing incidence of chemical adulteration in highly perishable foods such as milk and fish demands rapid, accessible, and environmentally sustainable detection strategies. Conventional laboratory-based analytical techniques provide high accuracy but are often impractical for routine, on-site monitoring due to cost, complexity, and time constraints. This has encouraged the exploration of biodegradable and naturally derived sensing materials for food quality assessment. This review evaluates recent advancements in anthocyanin-based paper strip developed for the detection of common milk and fish adulterants. The literature indicates that anthocyanins, due to their pH-sensitive structural transformations, enable visible colorimetric responses when exposed to chemical contaminants. When immobilized onto cellulose substrates and biopolymer matrices such as chitosan, these natural pigments demonstrate improved functionality for low-cost, disposable sensing applications. Studies report promising sensitivity toward adulterants including urea, detergents, formaldehyde, and ammonia compounds. Despite their potential, limitations such as pigment instability under light, temperature, and prolonged storage conditions remain key challenges. Ongoing research focuses on enhancing stability, improving detection limits, and integrating these indicators into intelligent packaging and portable diagnostic platforms. Overall, anthocyanin-based paper strip represents a sustainable and innovative direction in food adulteration detection, offering a bridge between laboratory precision and field-level applicability, with strong potential for future commercialization and smart food monitoring systems.