Production of Halochromic Dye Tablet from P Urple Heart Flower (setcreasea Purpurea) and Its Uses as Spoilage Indicator for Local Beverages

This study focuses on the production of halochromic dye tablets from the purple heart flower (Setcreasea purpurea) and their application as spoilage indicators for local beverages. Anthocyanins were extracted from the flower using acidified methanol, purified through column chromatography, and incorporated into tablet formulations with different binders—lactose and maize starch. The tablets were evaluated for mechanical properties, pH sensitivity, and spoilage detection in soya milk and ginger drink. The results demonstrated that lactose-bound tablets exhibited superior mechanical properties, with a higher crushing strength (8.0 kgf) and lower friability (0.00%), making them more stable for practical applications. In contrast, tablets formulated with maize starch had lower mechanical strength but disintegrated faster, which may enhance responsiveness to spoilage conditions. The halochromic dye tablets effectively detected pH variations in the beverages over a 12-hour period, indicating spoilage. Soya milk showed a pH drop from 4.7 to 4.2, while ginger drink exhibited a more pronounced decrease, with the pH of the plain purple heart tablet formulation shifting from 5.8 to 4.5. Corresponding colorimetric changes in the dye tablets provided a visual indication of beverage spoilage. These findings suggest that halochromic dye tablets from Setcreasea purpurea offer a cost-effective and eco-friendly solution for real-time food spoilage detection. The lactose-based formulation proved most suitable for practical applications, showing both durability and clear color responses to pH variations. Future studies should focus on improving the stability and scalability of these tablets for broader use in intelligent food packaging systems.