Abstract: The extraction technology and properties of water soluble dietary fiber (SDF) from tea through enzymatic method were studied. The results showed that the effect of pH was the most important, followed by temperature, enzyme dosage, time and ratio of solid-liquid. Through orthogonal test, the optimum conditions of extraction were obtained on the basis of single factor test, as follows: enzyme dosage 0.08 g/g, pH9.0, time 2 h, temperature 60℃ and ratio of solid-liquid 1∶20. The yield of SDF is 53.72%. SDF from tea is a superior dietary fiber with high capacities of water holding, swelling and oil holding, as well as good absorption on cholesterol and sodium cholate.

Key words: tea, water-soluble dietary fiber, enzymatic method, extraction, physicochemical properties