園藝作物天然色素之研究 1.梔子色素之抽取和化學性質

The extraction and some chemical properties of pigment in the fruits of Gardenia jasminoides Ellis. f. grandiflora Makino are studies. The stability of gardenia pigment is greatly influenced by stored in light condition than in dark. Under light condition, this pigment is more unstable when the pH value of the aqueous solution is not greater than 5. Gardenia pigment has better thermal stability while having been heated for 5 hours, it still maintains a high percentage (about 90%) of remaining. The existence of iron ions will accelerated the change of this pigment. The gardenia pigment is more stable in 75% alcohol solution than in pure water. And the former is the best suitable extraction solvent for this pigment extracted with gardenia fruits.