Properties and Stability of Pigment from Macadamia Shell

In this manuscript, properties and stability of the pigment from macadamia shell were investigated. Results indicated that this pigment was easily soluble in solvents with relatively strong polarity, such as water, methanol and ethanol but insoluble in chloroform, petroleum ether, ethyl acetate and ethyl ether. Temperature and solution p H showed remarkable effect on the stability of the pigment. The preservation rate of pigment decreased obviously with an increase in temperature. Extremely high or low p H values also could result in a decrease in pigment content. In addition, Na+, Cu2+, and Mn2+ revealed a color enhancement effect on this pigment, and K+ and Ca2+ could protect the pigment. In contrast, Fe2+, Fe3+, Al3+and Zn2+ in solution could obviously result in color fading. Moreover, it was found that the pigment was poorly tolerant to oxidants and light, while reducing agents showed little effect on the stability of the pigment. Some commonly used food additives possessed hyperchromic and color protecting effects on the pigment from macadamia shell.