反复冻融法对枸杞多糖溶出率的研究

Technique of Extracting Polysaccharides from Goji Berry by Repeated Freezing and Thawing Method

[目的]探究反复冻融法对枸杞多糖溶出率的影响。[方法]通过对解冻温度、冻结时间、冻融次数、冻结温度进行单因素试验及正交试验,验证反复冻融法对枸杞多糖的提取效果影响。[结果]当温度低于45℃时,枸杞多糖的溶出率随温度的升高而升高,当温度高于45℃时,枸杞多糖的溶出率却降低;随着冻融次数的增多,枸杞多糖的溶出率逐渐增大,但超过3次以后溶出率提升并不明显;随着冻结时间的增长,枸杞多糖的溶出率逐渐增大,当冻结时间超过3 h后,枸杞多糖溶出率趋于平稳,无明显变化;随着冻结温度的降低,枸杞多糖的融出率逐渐增大,当冻结温度低于-24℃后,枸杞多糖融出率趋于平稳,无明显变化。[结论]反复冻融法提取枸杞多糖的最佳工艺组合为:解冻温度45℃,冻融次数4次,冻结时间3 h,冻结温度-28℃。

[Objective] To study the effects of repeated freezing and thawing method on rate of extracting polysaccharides from Goji Berry.[Methods]Single factor experiment and orthogonal test were carried out for thawing temperature,freezing time,freezing and thawing times,and freezing temperature,to verify the effects of repeated freezing and thawing method on rate of extracting polysaccharides from Goji Berry.[Results]When the temperature was lower than 45 ℃,the dissolving rate of polysaccharides increases with temperature rise; when the temperature is higher than 45 ℃,the dissolving rate of polysaccharides drops; with increase in freezing-thawing times,the increase of dissolving rate of polysaccharides is slight when the freezing time exceeds 3 h; with increase in the freezing time,the dissolving rate of polysaccharides gradually increases,but when the freezing time exceeds 3 h,the dissolving rate of polysaccharides tends to become steady; when the freezing temperature drops,the dissolving rate of polysaccharides gradually rises,but when the temperature is lower than- 42 ℃,the dissolving rate of polysaccharides tends to become steady. [Conclusion]The optimal process combination of repeated freezing and thawing method for extracting polysaccharides from Goji Berry is as follows： 45 ℃ for thawing temperature,4 for repeated times; 3 h for freezing time;- 28 ℃ for freezing temperature.