DIETARY FIBER AND PREPARATION METHOD

The present invention provides a dietary fiber and a preparation method thereof, and the preparation method comprises the following steps: 1) mixing mulberry pomace with water, then pulping to obtain a pomace puree; 2) adding medium components to the pomace puree, then inoculating a compound strain for fermentation, and ending the fermentation when pH of a fermentation liquid is 4-5, to obtain a fermented puree; 3) subjecting the fermented puree to an alcohol precipitation treatment, filtering and drying a precipitate, to obtain the dietary fiber; where the compound strain comprises Lactobacillus plantarum, Monascus, and Bacillus subtilis. The preparation method performs a mixed fermentation to mulberry pomace by choosing a compound strain, thereby not only improving the total content of the dietary fiber in a product, but also improving the content of a soluble dietary fiber in the product. The present invention also relates to the Lactobacillus plantarum strain having a deposit number of GDMCC No. 60614.