International Journal of Food Science and Nutrition

Authors
Ashfak Ahmed Sabuz, Md Hafizul Haque Khan, Md Towhidur Rahman, Rahmatuzzaman Rana, Shyamal Brahma

Abstract
This study was conducted at the laboratory of Food Technology and Rural Industries, Bangladesh Agricultural University and Department of Chemistry, BAU, Mymensingh, Bangladesh. It was concerned with the extraction of annatto extract, a well-known natural food colorant, and the effect of solvents, food matrix, temperature and light on the stability of the color. During extraction, the reflux method gave the highest yield (10.1%) while the soxhlet method yielded 7.1% of dyes, Water soaking method yielded 8.93% of annatto color during 18 hour soaking period. The best background color was found at a concentration of 500 ppm. The annatto color was found quite stable in food matrix. Absorbance of annatto color exhibited almost unchanged over all sugar solution regardless of concentration. Absorbance reading and heating showed a linear relation with negative slope but with low value of slope of regression line. Annatto color was found highly sensitive to light. Oxidation was rapid within first 2 hours of incubation. There is minor change in the intensity of annatto color with the change of pH. Beyond the pH 3.8, color intensity as measured by absorbance reading showed almost close to control.