STUDY ON THE ULTRA-HIGH PRESSURE EXTRACTION OF POLYSACCHARIDES FROM LITCHI FRUIT

In this paper, the extraction of polysaccharides from litchi by ultra-high pressure extraction (UPE) was studied. Based on the monofactorial test, the optimum extraction conditions were made by using L₉ (3⁴) orthogonal design. The effects of UPE pressure, UPE time, grinding degree and the ratio of materials weight to solvent volume on the yield of polysaccharides in litchi were investigated. The optimum experimental parameters were determined as follows: UPE pressure 420 MPa, UPE time 5 min, grinding degree 80 mesh and the ratio of materials weight to solvent volume 1:15 (g:ml).The result was analyzed by variance test and showed that UPE time had a significant effect on extraction yield. The polysaccharides yield of UPE, SE, UAE and MAE were 8.11, 4.86, 6.43 and 5.56% and the extraction time were 5, 360, 10 and 10 min respectively. UPE is a better method for extraction polysaccharides from litchi for it has a higher yield in shorter time.