蓝莓色素的光热和化学稳定性研究

Study on the light, heat and chemical stabilities of blueberry fruit pigment

目的探讨光照、温度、pH、氧化还原剂、食品添加剂和金属离子对蓝莓色素稳定性影响。方法从蓝莓果实中提取纯化得到蓝莓色素,以色价、总花色苷和总多酚含量为指标考察色素的稳定性。结果蓝莓色素为水溶性色素,具有较强的光热稳定性,短时间(12 h)中等强度的光照(9000 lux以内)和50℃以内的加热处理(2 h以内)对酸性条件下的(pH<3.0)蓝莓色素的影响较小。在pH<4的条件下蓝莓色素颜色艳丽,稳定性好。蓝莓色素耐氧化还原性差,食品添加剂中蔗糖和柠檬酸具有护色作用,麦芽糊精对蓝莓色素有一定不良影响,Vc对色素有破坏作用。金属离子中,Zn^(2+)、Ca^(2+)有护色作用,K^+、Mg^(2+)对色素无影响,Na^+、Cu^(2+)和Fe^(2+)有不同程度的不良影响。结论蓝莓色素的光、热稳定性较化学稳定性强。

Objective To discuss the effects of light, temperature, pH value, oxidant （H2O2）, reductant （Na2SO3）, food additive and metallic ion on the stability of blueberry fruit pigment.Methods The stabilities of blueberry pigment from blueberry fruits were evaluated by the color value, total anthocyanins content and total polyphenols content after treatments. ResultsThe blueberry fruit pigment was resistive to light （within 9000 lux for 12 hours） and heat （within 50℃ for2 hours）, but sensitive to H2O2, Na2SO3 and pH value, which was more stable with bright color under the conditions of pH lower than 4.0. Sweeteners and acidity agents such as sugar and citric acid had protective effect on the stability of pigment, maltodextrin showed definite adverse effect on the pigment, and vitamin C showed remarkably degradation effect on the blueberry fruit pigment. Zn2＋and Ca2＋had a certain color protection or enhancement function, K＋ and Mg2＋had little effect on blueberry fruit pigment, and Na＋, Cu2＋ and Fe2＋ showed different degrees of adverse effect on the blueberry fruit pigment. ConclusionThe light stability and heat stability of blueberry pigment are stronger than its chemical stability.