Abstract:Taking Tie Guanyin residues as the research object, through single factor experiment and response surface methodology, the effects of extrusion water content, sleeve temperature and screw frequency on its assisted alkaline-enzyme combined extraction of tea residue protein hydrolysates (TPH) were discussed, and the functionalities of TPH was then investigated. The optimal extrusion assisted extractions were water content of tea residue material 15%, sleeve temperature 97 ℃, screw frequency 40 Hz. Under the conditions the extraction rate of TPH was improved to (71.37±0.09)%, which was close to the predicted result. The results of TPH antioxidant activity showed the IC50 values of DPPH· and ABTS+· were 23.4 μg/mL and 111.4 μg/mL, respectively, which were 18% and 32% lower than those of directly extracted sample; and except the decrease of emulsion stathe, the solubility, emulsifying activity index and foaming properties of TPH were all significantly improved (P<0.05). The results indicated that the extrusion assisted extraction process could well improve the functionalities of TPH, which makes its application in food system valuable and possible.