EVALUATION OF STABILITY OF NATURAL FOOD COLORANT EXTRACTED FROM ANNATTO SEED (BIXA ORELLANA) AT DIFFERENT PROCESSING AND STORAGE CONDITIONS

Abstract

There is a growing global demand for eco-friendly products, particularly in food, favoring natural colorants. However, these often lack durability compared to synthetics. Annatto dye from Bixa Orellana seeds exemplifies this natural colorant. This study investigates the stability of Annatto pigments, specifically bixin, and norbixin, under varying storage conditions including pH levels, sodium chloride concentrations, exposure to oxygen and light, and temperature variations. The method employed for annatto color extraction involves solvent extraction (using Ethanol) accompanied by ultrasonic treatment at 50°C for 30 minutes. Throughout the experimentation, losses in both bixin and norbixin were monitored and determined by the measured via UV spectroscopy (487nm), with samples being evaluated every 2 days over two weeks. Notably, bixin demonstrated the highest rate of mass loss at pH = 5, followed by pH = 3, and the lowest at pH = 7. The addition of different concentrations of NaCl to the annatto preservation medium resulted in the highest bixin loss at 3% NaCl and the lowest at 0.4% NaCl. Moreover, prolonged exposure to diffused light notably impacted the stability of annatto, while the presence or absence of oxygen did not yield a significant effect. Storage under dark conditions at 4°C and room temperature (27°C) both led to less bixin losses. In contrast, rapid and substantial bixin loss was observed during frying at temperatures ranging from 170 to 180°C. Bixin showed the highest stability in a naturally alkaline environment (pH = 7), with sodium chloride content below 3%, minimal light exposure, and cold storage at 4°C.