Effect of the different extracting methods on functional properties of tea-residue protein

The effects of modification and functional properties were investigated by the alkali solution extraction, alkali solution extraction with extrusion pretreatment and enzymatic extraction with extrusion pretreatment from the Danzong tea-residue. The results showed that the hydroscopicity, waterholding capacity, foamability and emulsibility of tea-residue protein by alkali solution extraction with extrusion pretreatment increased by 25%, 43.43%, 8.79% and 5.57% respectively and oil absorbability decreased by 8.67% compared with the alkali solution extraction. The same case with the functional properties increased by 34.73%, 86.87%, 18.01% and 12.46% respectively and oil absorbability decreased by 18.50% of enzymatic extraction with extrusion pretreatment. The conclusion was a most useful processing method to improve tea-residue protein functional properties for extrusion pretreatment.