天然花色苷的资源收集及稳定性测定

通过天然花色苷材料野外采集，共得到50种植物的花色苷样品，采用pH 1.0/pH 4.5溶液吸光值（△OD）差值法，对这些花色苷提取液进行了1年的测定和筛选，筛选出了花色苷颜色稳定性较好的桔梗（Platycodon grandiflorua A.）、蜀葵（Althaea. Rosea L.）、翠雀（Delphinium grandiflorum L.）和日本红菊（Chrysanthemum morifolium Ramat）等4种植物资源。对这4种花色苷进行酸碱性、光照、金属离子、热处理等条件下的稳定性测定，表明在pH4.0以下稳定，高于pH4.0稳定性则明显下降。日光、pH 1.0条件下上述4种花色苷溶液的半衰期分别为339d、255d、226d和234d。钙、镁离子对花色苷的稳定性无影响，铝、铜、锡和铁的存在降低花色苷的稳定性，其中铝影响较小，铜锡影响较大，铁影响最大。在100℃ 20min pH1.0热处理下色素损失率分别为2.7%、29.2%、20.0%和7.1%。桔梗花色苷稳定性明显优于其余3种花色苷。结果表明上述4种花色苷有希望开发成为食品色素添加剂。

Collection and Stability determination of Natural Anthocyanin

To search for natural and stable colorant for food industry, total 50 plant species containing anthothyanin were collected, the anthocyanin samples were extracted from different organs, and the stability was evaluated according to colour duration in acidic solution with pH 1.0 and pH 4.5 in one year. Finally 4 anthothyanin samples with longer color duration extracted from Platycodon (Platycodon grandiflorua A.), Hollyhock (Althaea Rosea L.), Larkspur (Delphinium grandiflorum L.) and Japanese chrysanthemum (Chrysanthemum morifolium Ramat) respectively were obtained. The characteristics of the anthothyanin were studied according to procession conditions, such as different pH, light, heat and metal ions. It was showed that the anthothyanin were stable bellow pH4.0, stability decreased sharply above pH4.0, and their half lifetime were 339d, 255d, 226d and 234d respectively under pH 1.0 and sunlight. Different metal ions affected stability at different rate, calcium and magnesium had no effect on stability, while aluminium decreased stability slightly, the presents of copper, stannum and iron caused obvious stability decline, iron did the most among the metal ions tested in this study. The lost rate of the 4 anthothyanin samples were 2.7%, 29.2%, 20.0% and 7.1% respectively under 100℃, pH1.0 treatment for 20min, which shows anthothyanin from Platycodon have a higher stability than the other 3 samples. The results show that the anthothyanin from the 4 species could be developed as potential additives in food industry.