升华法纯化茶叶咖啡碱及其对胶原酶和弹性蛋白酶的抑制作用研究

Purification of tea caffeine by sublimation and its inhibitory activity on collagenase and elastase

为实现废弃茶叶资源中咖啡碱的高效提取,并促进茶叶咖啡碱的开发利用,以液液萃取工艺提取茶多酚后的萃余液为原料,采用升华法分离纯化其中的咖啡碱,考察不同前处理剂和升华条件对咖啡碱得率的影响,并运用响应面分析法优化升华工艺参数,最后分析了茶叶咖啡碱对胶原酶和弹性蛋白酶的体外抑制能力。结果表明,升华法分离纯化茶叶咖啡碱的最佳工艺条件为:升华前使用碳酸钠处理萃余液,碳酸钠添加量与萃余液固形物质量比为2.3∶1,升华温度214℃、升华时间28 min,在此条件下咖啡碱得率为76.21%,咖啡碱纯度>98.5%。另外,茶叶咖啡碱对胶原酶和弹性蛋白酶具有良好的抑制作用,质量浓度为1 mg/mL时对胶原酶和弹性蛋白酶的抑制率分别达到46.72%和38.43%。该工艺较传统工艺较大地提高了咖啡碱得率,更加经济安全,具有较好的工业运用前景,同时得到的茶叶咖啡碱可作为天然的胶原酶和弹性蛋白酶抑制剂,在相关护肤产品中可被进一步运用。

In order to efficiently extract caffeine from waste tea resources and promote the development and utilization of tea caffeine,the raffinate after extracting tea polyphenols by liquid-liquid extraction was used as raw material to purify caffeine through sublimation.Effects of pretreatment agents and sublimation conditions on caffeine yield were investigated,and response surface methodology was used to optimize the process parameters,followed by analyzing the inhibition of caffeine on collagenase and elastase in vitro.The optimum sublimation conditions were as follows:sodium carbonate was used as pretreatment agent,the mass ratio of sodium carbonate addition to solidified raffinate was 2.3∶1,the sublimation temperature was 214℃,and the sublimation time was 28 min.Under these conditions,the yield of caffeine was 76.21%,and the purity of caffeine exceeded 98.5%.Furthermore,tea caffeine had an excellent inhibitory activity on collagenase and elastase,and the inhibition rates at 1 mg/mL were 46.72%and 38.43%,respectively.Compared with the traditional process,this process not only greatly improves the yield of caffeine,but also is much more economical and safer,and has a great industrial application prospect.Meanwhile,the obtained tea caffeine can be used as a natural collagenase and elastase inhibitor,and get a further utilization in related skin care products.