苦荞黄酮类化合物的稳定性研究

目的研究苦荞黄酮类化合物的稳定性。方法用分光光度法研究储存时间、光照、加热、pH值、食品添加剂、氧化剂、还原剂和金属离子等条件对苦荞麸皮中类黄酮化合物的影响;比较了两种提取方法获得的黄酮提取物在上述条件下的稳定性。结果苦荞黄酮溶液在暗处存放60 d无变化,但光照能破坏其结构;苦荞黄酮溶液耐热性强,90℃保温1 h不受影响;在酸性条件下苦荞黄酮溶液稳定,在中性、碱性环境中不稳定,碱性对其有强破坏作用;常用食品添加剂在安全使用量范围内,柠檬酸、苹果酸、抗坏血酸、蔗糖对苦荞黄酮稳定性无影响,苯甲酸钠对其有一定的影响,氧化剂H2O2对其稳定性无明显影响,还原剂Na2SO3对其有强烈破坏作用;金属离子K+、Na+、Ca2+、Mg2+对苦荞黄酮稳定性无明显影响,Cu2+、Fe2+、Al3+对其影响较大,Fe3+影响最大。结论各因素对苦荞黄酮2#提取物的影响较1#提取物大,即1#提取物的稳定性略高于2#提取物。

Studied on the Stability of Flavonoids from Tartary Buckwheat

Objective The effects of different conditions on flavonoids from tartary buckwheat bran were studied by spectrophotometry,including preserving time,light,heat,pH,food additives,oxidizer,reducing agents and metal ions.Furthermore,the stabilities of tartary buckwheat flavonoids extracted by two methods were compared.Results showed that: The flavonoids solution did not change after 60 days in dark,but its structure can be damaged by light.The flavonoids solution was heat-resistant.It had not been affected after incubated in 90℃ for 1h.The flavonoids was stable in acidic conditions,while unstable in neutral and alkaline conditions,alkaline had strong damaging effects.Within safe dose of food additions such as Citric-acid,Malic-acid Ascorbic-acid and sugar,no effect on the stability of flavonoids solution have shown.Sodium-benzoate had a certain effect on it.The influence of oxidant H2O2 on stability of flavonoids was not obvious,the reducing agent Na2SO3 had a strongly destructive effect on it.The metal ions such as K+,Na+,Ca2+,Mg2+ had no obvious effect on the stability of tartary buckwheat flavonoids.While Cu2+,Fe2+,Al3+ had larger effect,and Fe3+ had the most.