Abstract:Fungal extracellular polysaccharides possess rich biological activities，making them a focal point in the study of natural polysaccharides.In this study，the extracellular polysaccharides from Floccularia luteovi?rens（FEPS）were studied to determine the minimum inhibitory concentration（MIC）and their inhibitory effect on tyrosinase activity，and the effect of fungal polysaccharide concentration in the composite solution on the quality of Pacific white shrimp（Penaeus vannamei）under refrigeration at 4 ℃was investigated.The results in?dicated that the MIC of FEPS against Escherichia coli is 2.0 g/L.The extracellular polysaccharides and certain inhibitory effect on tyrosinase activity，and the inhibition rates of tyrosinase monophenolase and biphenolase reached（47.67±0.49）% and（44.04±0.21）% at 1.5 g/L，respectively.During the middle and later stages of storage（3-12 d）of Pacific white shrimp，the group treated with 1.0 g/L FEPS composite solution outperformed other treatment groups in terms of melanosis degree，color quality，sensory scores，total volatile basic nitrogen（TVB?N）content，thiobarbituric acid（TBA）value，and total colony count.In summary，FEPS and the pullu?lan had synergistic effects on shrimp preservation，and 1.0 g/L FEPS?pullulan composite solution was able to inhibit the rate of quality deterioration of shrimp effectively，extending the shelf life to 9 d.