FOOD SCIENCE

• Processing Technology • Previous Articles     Next Articles

Extraction and Stability of Purple Sweet Potato Peel Pigment

Haini·BAYINDA, Abdulla·ABBAS   

  1. College of Life Science and Technology, Xinjiang University, Ürümqi 830046, China
  • Online:2016-07-25 Published:2016-07-26
  • Contact: Abdulla·ABBAS

Abstract:

Box-Behnken experimental design and response surface methodology were employed to optimize the conditions
for extraction of purple sweet potato peel pigment. Also, the effect of various physicochemical factors on the stability of the
pigment was addressed. The optimum extraction conditions were obtained as follows: 0.5% citric acid:anhydrous ethanol
at a volume ratio of 1:1 as extraction solvent; solid-to-solvent ratio, 1:60 (g/mL); temperature, 50 ℃; and time, 20 min.
Under these conditions, the predicted absorbance value of the pigment solution was 0.843 and the experimental value was
0.838. The pigment was unstable under light and strong alkali conditions (pH > 7). It was relatively stable at temperatures
between 4 and 60 ℃. Metal ions including K+, Ca2+, Na+, Zn2+, Mg2+, Cu2+, Mn2+, and Fe3+ were helpful in the degradation of
the pigment. Within the safe dosage range, its stability was hardly affected by benzoic acid, sorbic acid, citric acid, sucrose,
soluble starch, glucose, and sodium chloride. Therefore, it can be used as food coloring agent.

Key words: purple sweet potato peel, pigment, response surface methodology, stability

CLC Number: