Optimization of extraction and stability characterization of rose petal natural dye: A standardized approach

Aim: Standardization of natural dye extraction process from the petals of rose flower for maximum yield of natural dye. Methodology: Optimization of natural dye extraction process was conducted using Box Behnken Design of Response Surface Methodology followed by stability studies to study the effect of different factors involved in the degradation of extracted anthocyanin. Results: Optimal anthocyanin extraction from rose petals, yielded 19.653 mg g-1 with a high redness index of 240.314, was achieved at 25°C using a 1:5 solid-to-solvent ratio and 0.015% HCl. Anthocyanin stability decreased exponentially with increased temperature and time, with natural light exposure causing the most significant degradation. The dyes color shifted from bright red in acidic condition to blue in alkaline conditions. Interpretation: The study successfully identified optimal conditions for extracting vibrant red anthocyanin dye from roses. However, the sensitivity of dye to heat, light, and pH variations indicate a need for careful handling and storage to maintain its colour and stability. Key words: Anthocyanin, Natural dye, Optimization, Rose flower petals, Stability