Study on extraction of a pigment from pineapple peel and its stability

The process of extracting a pigment from pineapple peel was studied,which was optimized through orthogonal experi- ments. The optimum conditions for pigment extraction were determined as:microwave treatment at 50℃ for 150s,microwave power 300W and solid-solvent ratio 1∶10 (g/ml). In addition,a study was carried out on the influences of microwave temperature, pH,metal ions and some conventional food additives on the stability of the pigment. The results showed that VC and metal ions Fe2+,Fe3+ and Cu2+ had significant influences on its stability,and that the pigment was relatively stable in acidic and neutral envi- ronments but unstable in a strong alkaline environment.