Natural plant extracts for quality assessment in milk by replacing conventional color reduction methods

Abstract Our study proposes a novel approach using aqueous extracts of plant material Ruellia simplex to screen milk for microbiological quality rapidly. We tested plant extracts for colour changes at various pH levels, with different dyes as the control. The differential pH method was used to assess milk freshness using plant extracts. The Ruellia simplex flower extract was tested with its pH-dependent colour shift (6; purple to 1; dark pink). The Ruellia simplex extract has an anthocyanin content of 0.609 g/ml. The approach demonstrated great linearity (R 2 = 0.978), 100% accuracy, and reproducibility. The limits of detection and quantification were 0.027 and 0.082 g/mL, respectively. This technology has the potential to revolutionise milk quality testing by providing a cost-effective and efficient alternative to traditional dye-based procedures, especially in rural and remote locations. Its application in intelligent food packaging has the potential to alter dairy sector practices internationally by allowing for accessible and real-time quality monitoring.