Effectiveness of Hibiscus Flower Extract (Hibiscus rosa-sinensis L.) and Red Galangal as a Freshness Indicator Label for Chicken Meat

Abstract

Chicken meat, among the most consumed animal proteins globally, is highly susceptible to spoilage due to its high moisture and nutrient content, promoting rapid microbial growth under inadequate storage. This study developed and evaluated an anthocyanin-based indicator label using hibiscus flower extract (Hibiscus rosa-sinensis L.) and red galangal (Alpinia purpurata) for freshness monitoring of raw chicken meat in intelligent packaging. Indicator films were formulated at three hibiscus extract concentrations (14%, 16%, 18%) combined with ganyong starch at 6% and 8%, and evaluated through color change (mean RGB via ImageJ, NIH, USA), pH, weight loss, and organoleptic testing at 25°C over 12 hours, with observations every 3 hours. Results showed visually distinguishable color transitions from red to dark green corresponding to meat deterioration, with the strongest response in the A1S formulation (14% hibiscus extract, 6% ganyong starch). Meat pH increased progressively from 5.64 at hour 0 to 6.67 at hour 12, consistent with volatile amine accumulation during decomposition. Organoleptic acceptability declined during storage, reaching the non-acceptable range by the later observation period. Pearson correlation analysis revealed a statistically significant but weak negative relationship between pH and mean RGB (r = -0.218; p = 0.039; r² = 0.047), indicating pH explained only 4.7% of color response variance. These results should be interpreted as preliminary rather than strong predictive validation. Given the absence of microbiological confirmation, TVB-N measurement, and instrumental colorimetry, the findings nonetheless suggest the potential of hibiscus-based films as freshness indicator labels for intelligent packaging.