Study on preparation technology of soluble dietary fiber extracted from tea residue by Lactobacillus fermentation

Taking tea residue as the raw material, soluble dietary fiber (SDF) was prepared by mixed strain of Lactobacillus bulgaricus and Streptococcus thermophilus fermentation (1∶1) . Effect of inoculating volume, fermentation temperature, fermentation time and ratios of material and liquid on yield of SDF were investigated, the fermentation conditions were optimized by single-factor experiments and orthogonal test. The result showed that the optimum condition of extracting SDF was as follows:inoculating volume 3%, fermentation temperature 40℃, fermentation time 25h, ratio of material and liquid by 1∶10. Under these conditions, the average SDF yield was 10.99%.