吸湿对不同干制方式下枸杞粉活性成分及色泽变化的影响

探讨晒干、烘干和冻干对枸杞粉吸湿前后多糖、黄酮和类胡萝卜素含量的影响,并采用高效液相色谱法测定了3种干制方式对黄酮类和胡萝卜素类化合物的种类和含量的影响,研究吸湿前后的色泽变化。结果表明:相同干制方式下,枸杞粉吸湿后多糖和类胡萝卜素含量均显著降低(p<0.05);黄酮含量显著升高(p<0.05),其中阿魏酸、咖啡酸、对香豆酸含量减少,而槲皮素、芦丁含量增大;3种干制方式的枸杞粉吸湿后的L*、a*、b*值较吸湿前均显著降低(p<0.05)。不同干制方式下,冻干枸杞粉的多糖和类胡萝卜素含量均高于其他两种干制方式,而烘干枸杞粉黄酮含量最高;其色泽参数显示,吸湿前:烘干>晒干>冻干,吸湿后:冻干>烘干>晒干。综合而言,吸湿对不同干制方式下枸杞粉活性成分的保留及色泽均有不利影响。

Effect of moisture on the active components and color of Lycium barbarum powder under different drying method

The effects of different drying methods on Lycium barbarum powder were explored to find the polysaccharides,flavonoids and carotenoids change of contents before and after moisture absorption. HPLC was adapted to assay the content changes of the main flavonoids and carotenoids of 3 kinds of drying methods. And the color changes before and after moisture absorption. The result showed that the contents of polysaccharides and carotenoids in the wolfberry powder were significantly decreased(p<0.05)after the same drying method. And the content of flavonoids in wolfberry powder was significantly increased(p<0.05). The content of ferulic acid,caffeic acid,the coumaric acid which in flavonoids decreased,and quercetin,rutin increased. The color parameters of L*,a* and b* showed that the three kinds of dried wolfberry powder were significantly lower than those before moisture(p<0.05). The contents of polysaccharides and carotenoids in freeze-dried wolfberry powder were higher than those in the other two methods. But the flavonoid contents were the highest in hot-air-dried wolfberry powder. Its color parameters display that color differences before moisture absorption were as follows:hot-air-dried>sun-dried>freeze-dried,after moisture absorption Color differences were freeze-dried>hot-air-dried>sun-dried. Overall,the moisture absorption on the different dry way under the wolfberry powder active ingredient retention and color have a negative impact.