Process Optimization for Ultra-high Pressure Extraction of Tea Polyphenols

In this paper,ultra-high pressure technique was applied for the extraction of tea polyphenols.On the basis of single factor experiments,the optimal extraction process for tea was investigated to explore the effects of solvent concentration,material/liquid ratio,extraction pressure and pressure treatment time on the extraction rate of tea polyphenols.Meanwhile,the extraction rates of tea polyphenols,caffeine,soluble sugars and amino acids between ultra-high pressure extraction and normal high temperature extraction were compared.The results indicated that the optimal extraction processing parameters were 70% ethanol,material/liquid ratio of 1:40,extraction pressure of 200 MPa,and pressure treatment time of 10 min.Under the optimal extraction conditions,the extraction rates of tea polyphenols,amino acids,soluble sugars and caffeine were 26.61%,3.87%,4.76% and 2.95%,respectively,which were higher than those of hot water extraction.Therefore,ultra-high pressure extraction has the advantages of clear supernatant as well as short time and non-thermal extraction.