碱法提取普洱茶渣膳食纤维的工艺优化

Optimization of Alkaline Extraction of Dietary Fiber from Pu-erh Tea Residue

以普洱茶渣为原料,通过碱法提取茶渣中膳食纤维,研究影响因素(碱液浓度、碱解温度、碱解时间和料液比)对普洱茶渣中膳食纤维得率的影响。结合单因素和响应面试验得到最优提取工艺参数为碱液浓度3.35%、碱解温度100℃、碱解时间2.36 h、料液比1∶28(g/mL)。在该条件下,普洱茶渣中膳食纤维的得率为82.26%,较提取前极显著提高(P<0.001)。提取后的茶渣膳食纤维中纤维素、半纤维素、木质素和果胶的含量分别为52.10%、14.20%、15.30%和5.00%,以不溶性纤维为主。

Dietary fiber was extracted from Pu-erh tea residue by alkaline method.The factors(alkali concentration,alkaline extraction temperature,extraction time,and solid-to-liquid ratio)influencing the dietary fiber yield were studied.The extraction conditions were optimized by single factor test and response surface methodology as extraction with 3.35%alkali and the solid-to-liquid ratio of 1∶28(g/mL)at 100℃for 2.36 h.Under these conditions,the yield of dietary fiber from Pu-erh tea residue was 82.26%,which was significantly higher than that before extraction(P<0.001).The content of cellulose,hemicellulose,lignin,and pectin in dietary fiber from the tea residue was 52.10%,14.20%,15.30%and 5.00%,respectively,and insoluble fiber was the main fiber component.